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15 Commits

Author SHA1 Message Date
Ana Maria Martinez Gomez
3831f1c104 extractors: Do not use generate_api_features
`generate_api_features` was merged with the implementation of
`generate_import_features` and replaced by `generate_symbol`:
2b2656c2a3
 Use the new function in the miasm backend implementation.
2021-02-05 15:41:13 +01:00
Ana Maria Martinez Gomez
dc828e82b3 extractors: add required loc_db
Since the following PR, miasm requires LocationDB in the object's
constructor instead of creating a new LocationDB:
https://github.com/cea-sec/miasm/pull/1274

This was not the case at the point I started the miasm backend
implementation. Adapt the code to work with this change, which also
means interacting with miasm in a better way.
2021-02-05 15:41:04 +01:00
Ana María Martínez Gómez
2e98ba990c tests: enable tests for miasm
Everything is red :( Some tests are failing due to the not yet
implemented features. In addition, it looks like miasm has problems
disassembling some of the used files.
2021-02-03 15:07:31 +01:00
Ana María Martínez Gómez
d008fef23f extractors: enable miasm in Python3
Do not make miasm the default until we have ensured everything works as
it should.
2021-02-03 15:07:31 +01:00
Ana María Martínez Gómez
fe458c387a extractors: use block and feature offset function
`f` and `bb` in miasm are not an integer. Introduce `block_offset()` and
`feature_offset()` in the extractors and use them in main to solve this.

Related to https://github.com/cea-sec/miasm/pull/1277
2021-02-03 12:50:56 +01:00
Ana María Martínez Gómez
3e52c7de23 features: store mnemomics lower case
miasm extracts mnemonic capitalized while other backends do it
lowercase. To ensure capa works with all of them, use lower case in the
Mnemomic constructor.
2021-02-03 12:50:56 +01:00
Ana María Martínez Gómez
2d1e7946e3 extractors: Implement extract_insn_mnemonic_features
Extract insn mnemonic features in miasm.
2021-02-03 12:50:56 +01:00
Ana María Martínez Gómez
f2fe173ef3 extractors: Implement extract_insn_api_features
Extract insn API features in miasm.
2021-02-03 12:50:56 +01:00
Ana María Martínez Gómez
b2fc52d390 extractors: implement miasm insn features template
Add a template for insn features. These features needs some work and
there are many of them, so I'll introduce them independently in their
own commit.
2021-02-03 12:50:56 +01:00
Ana María Martínez Gómez
5ba4629c3c extractors: implement miasm function features
Add function features.
2021-02-03 12:50:56 +01:00
Ana María Martínez Gómez
4fc9c77791 extractors: implement miasm basic block features
Add basic block features.
2021-02-03 12:50:55 +01:00
Ana María Martínez Gómez
31ba9ee1b3 extractors: Implement get_basic_blocks in miasm
Implement `get_basic_blocks` in `MiasmFeatureExtractor`.
2021-02-03 12:50:55 +01:00
Ana María Martínez Gómez
b4a808ac76 extractors: Implement get_functions in miasm
Implement `get_functions` in `MiasmFeatureExtractor`. It is a proof of
concept, which just considers all loc_keys targets of calls a function.
This is enough to test feature extraction against the functions. A final
version should include other function recognition techniques and be
ported to miasm.
2021-02-03 12:50:55 +01:00
Ana María Martínez Gómez
0f030115d1 extractors: Implement cfg in miasm
Implement `_build_cfg()` in `MiasmFeatureExtractor`.

Co-authored-by: William Ballenthin <william.ballenthin@fireeye.com>
2021-02-03 12:50:55 +01:00
Ana María Martínez Gómez
42573d8df2 extractors: implement miasm file features
Begin to implement miasm backend. Add file features.

This implementation needs:
- https://github.com/cea-sec/miasm/pull/1273

Co-authored-by: William Ballenthin <william.ballenthin@fireeye.com>
2021-02-03 12:50:51 +01:00
237 changed files with 9814 additions and 70631 deletions

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@@ -1,21 +0,0 @@
# See here for image contents: https://github.com/microsoft/vscode-dev-containers/tree/v0.233.0/containers/python-3/.devcontainer/base.Dockerfile
# [Choice] Python version (use -bullseye variants on local arm64/Apple Silicon): 3, 3.10, 3.9, 3.8, 3.7, 3.6, 3-bullseye, 3.10-bullseye, 3.9-bullseye, 3.8-bullseye, 3.7-bullseye, 3.6-bullseye, 3-buster, 3.10-buster, 3.9-buster, 3.8-buster, 3.7-buster, 3.6-buster
ARG VARIANT="3.10-bullseye"
FROM mcr.microsoft.com/vscode/devcontainers/python:0-${VARIANT}
# [Choice] Node.js version: none, lts/*, 16, 14, 12, 10
ARG NODE_VERSION="none"
RUN if [ "${NODE_VERSION}" != "none" ]; then su vscode -c "umask 0002 && . /usr/local/share/nvm/nvm.sh && nvm install ${NODE_VERSION} 2>&1"; fi
# [Optional] If your pip requirements rarely change, uncomment this section to add them to the image.
# COPY requirements.txt /tmp/pip-tmp/
# RUN pip3 --disable-pip-version-check --no-cache-dir install -r /tmp/pip-tmp/requirements.txt \
# && rm -rf /tmp/pip-tmp
# [Optional] Uncomment this section to install additional OS packages.
# RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
# && apt-get -y install --no-install-recommends <your-package-list-here>
# [Optional] Uncomment this line to install global node packages.
# RUN su vscode -c "source /usr/local/share/nvm/nvm.sh && npm install -g <your-package-here>" 2>&1

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@@ -1,51 +0,0 @@
// For format details, see https://aka.ms/devcontainer.json. For config options, see the README at:
// https://github.com/microsoft/vscode-dev-containers/tree/v0.233.0/containers/python-3
{
"name": "Python 3",
"build": {
"dockerfile": "Dockerfile",
"context": "..",
"args": {
// Update 'VARIANT' to pick a Python version: 3, 3.10, 3.9, 3.8, 3.7, 3.6
// Append -bullseye or -buster to pin to an OS version.
// Use -bullseye variants on local on arm64/Apple Silicon.
"VARIANT": "3.10",
// Options
"NODE_VERSION": "none"
}
},
// Set *default* container specific settings.json values on container create.
"settings": {
"python.defaultInterpreterPath": "/usr/local/bin/python",
"python.linting.enabled": true,
"python.linting.pylintEnabled": true,
"python.formatting.autopep8Path": "/usr/local/py-utils/bin/autopep8",
"python.formatting.blackPath": "/usr/local/py-utils/bin/black",
"python.formatting.yapfPath": "/usr/local/py-utils/bin/yapf",
"python.linting.banditPath": "/usr/local/py-utils/bin/bandit",
"python.linting.flake8Path": "/usr/local/py-utils/bin/flake8",
"python.linting.mypyPath": "/usr/local/py-utils/bin/mypy",
"python.linting.pycodestylePath": "/usr/local/py-utils/bin/pycodestyle",
"python.linting.pydocstylePath": "/usr/local/py-utils/bin/pydocstyle",
"python.linting.pylintPath": "/usr/local/py-utils/bin/pylint"
},
// Add the IDs of extensions you want installed when the container is created.
"extensions": [
"ms-python.python",
"ms-python.vscode-pylance"
],
// Use 'forwardPorts' to make a list of ports inside the container available locally.
// "forwardPorts": [],
// Use 'postCreateCommand' to run commands after the container is created.
"postCreateCommand": "git submodule update --init && pip3 install --user -e .[dev] && pre-commit install",
// Comment out to connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
"remoteUser": "vscode",
"features": {
"git": "latest"
}
}

9
.gitattributes vendored
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# Set the default behavior, in case people don't have core.autocrlf set.
* text=auto
# Explicitly declare text files you want to always be normalized and converted
# to native line endings on checkout.
*.py text
*.yml text
*.md text
*.txt text

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@@ -1,46 +1,46 @@
# Contributor Covenant Code of Conduct
## Our Pledge
In the interest of fostering an open and welcoming environment, we as contributors and maintainers pledge to making participation in our project and our community a harassment-free experience for everyone, regardless of age, body size, disability, ethnicity, gender identity and expression, level of experience, nationality, personal appearance, race, religion, or sexual identity and orientation.
## Our Standards
Examples of behavior that contributes to creating a positive environment include:
* Using welcoming and inclusive language
* Being respectful of differing viewpoints and experiences
* Gracefully accepting constructive criticism
* Focusing on what is best for the community
* Showing empathy towards other community members
Examples of unacceptable behavior by participants include:
* The use of sexualized language or imagery and unwelcome sexual attention or advances
* Trolling, insulting/derogatory comments, and personal or political attacks
* Public or private harassment
* Publishing others' private information, such as a physical or electronic address, without explicit permission
* Other conduct which could reasonably be considered inappropriate in a professional setting
## Our Responsibilities
Project maintainers are responsible for clarifying the standards of acceptable behavior and are expected to take appropriate and fair corrective action in response to any instances of unacceptable behavior.
Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, or to ban temporarily or permanently any contributor for other behaviors that they deem inappropriate, threatening, offensive, or harmful.
## Scope
This Code of Conduct applies both within project spaces and in public spaces when an individual is representing the project or its community. Examples of representing a project or community include using an official project e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event. Representation of a project may be further defined and clarified by project maintainers.
## Enforcement
Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team. All complaints will be reviewed and investigated and will result in a response that is deemed necessary and appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.
Project maintainers who do not follow or enforce the Code of Conduct in good faith may face temporary or permanent repercussions as determined by other members of the project's leadership.
## Attribution
This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4, available at [https://contributor-covenant.org/version/1/4][version]
[homepage]: https://contributor-covenant.org
[version]: https://contributor-covenant.org/version/1/4/
# Contributor Covenant Code of Conduct
## Our Pledge
In the interest of fostering an open and welcoming environment, we as contributors and maintainers pledge to making participation in our project and our community a harassment-free experience for everyone, regardless of age, body size, disability, ethnicity, gender identity and expression, level of experience, nationality, personal appearance, race, religion, or sexual identity and orientation.
## Our Standards
Examples of behavior that contributes to creating a positive environment include:
* Using welcoming and inclusive language
* Being respectful of differing viewpoints and experiences
* Gracefully accepting constructive criticism
* Focusing on what is best for the community
* Showing empathy towards other community members
Examples of unacceptable behavior by participants include:
* The use of sexualized language or imagery and unwelcome sexual attention or advances
* Trolling, insulting/derogatory comments, and personal or political attacks
* Public or private harassment
* Publishing others' private information, such as a physical or electronic address, without explicit permission
* Other conduct which could reasonably be considered inappropriate in a professional setting
## Our Responsibilities
Project maintainers are responsible for clarifying the standards of acceptable behavior and are expected to take appropriate and fair corrective action in response to any instances of unacceptable behavior.
Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, or to ban temporarily or permanently any contributor for other behaviors that they deem inappropriate, threatening, offensive, or harmful.
## Scope
This Code of Conduct applies both within project spaces and in public spaces when an individual is representing the project or its community. Examples of representing a project or community include using an official project e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event. Representation of a project may be further defined and clarified by project maintainers.
## Enforcement
Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team. All complaints will be reviewed and investigated and will result in a response that is deemed necessary and appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.
Project maintainers who do not follow or enforce the Code of Conduct in good faith may face temporary or permanent repercussions as determined by other members of the project's leadership.
## Attribution
This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4, available at [https://contributor-covenant.org/version/1/4][version]
[homepage]: https://contributor-covenant.org
[version]: https://contributor-covenant.org/version/1/4/

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@@ -1,210 +1,197 @@
# Contributing to Capa
First off, thanks for taking the time to contribute!
The following is a set of guidelines for contributing to capa and its packages, which are hosted in the [Mandiant Organization](https://github.com/mandiant) on GitHub. These are mostly guidelines, not rules. Use your best judgment, and feel free to propose changes to this document in a pull request.
#### Table Of Contents
[Code of Conduct](#code-of-conduct)
[What should I know before I get started?](#what-should-i-know-before-i-get-started)
* [Capa and its Repositories](#capa-and-its-repositories)
* [Capa Design Decisions](#design-decisions)
[How Can I Contribute?](#how-can-i-contribute)
* [Reporting Bugs](#reporting-bugs)
* [Suggesting Enhancements](#suggesting-enhancements)
* [Your First Code Contribution](#your-first-code-contribution)
* [Pull Requests](#pull-requests)
[Styleguides](#styleguides)
* [Git Commit Messages](#git-commit-messages)
* [Python Styleguide](#python-styleguide)
* [Rules Styleguide](#rules-styleguide)
## Code of Conduct
This project and everyone participating in it is governed by the [Capa Code of Conduct](CODE_OF_CONDUCT.md). By participating, you are expected to uphold this code. Please report unacceptable behavior to the maintainers.
## What should I know before I get started?
### Capa and its repositories
We host the capa project as three GitHub repositories:
- [capa](https://github.com/mandiant/capa)
- [capa-rules](https://github.com/mandiant/capa-rules)
- [capa-testfiles](https://github.com/mandiant/capa-testfiles)
The command line tools, logic engine, and other Python source code are found in the `capa` repository.
This is the repository to fork when you want to enhance the features, performance, or user interface of capa.
Do *not* push rules directly to this repository, instead...
The standard rules contributed by the community are found in the `capa-rules` repository.
When you have an idea for a new rule, you should open a PR against `capa-rules`.
We keep `capa` and `capa-rules` separate to distinguish where ideas, bugs, and discussions should happen.
If you're writing yaml it probably goes in `capa-rules` and if you're writing Python it probably goes in `capa`.
Also, we encourage users to develop their own rule repositories, so we treat our default set of rules in the same way.
Test fixtures, such as malware samples and analysis workspaces, are found in the `capa-testfiles` repository.
These are files you'll need in order to run the linter (in `--thorough` mode) and full test suites;
however, they take up a lot of space (1GB+), so by keeping `capa-testfiles` separate,
a shallow checkout of `capa` and `capa-rules` doesn't take much bandwidth.
### Design Decisions
When we make a significant decision in how we maintain the project and what we can or cannot support,
we will document it in the [capa issues tracker](https://github.com/mandiant/capa/issues).
This is the best place review our discussions about what/how/why we do things in the project.
If you have a question, check to see if it is documented there.
If it is *not* documented there, or you can't find an answer, please open a issue.
We'll link to existing issues when appropriate to keep discussions in one place.
## How Can I Contribute?
### Reporting Bugs
This section guides you through submitting a bug report for capa.
Following these guidelines helps maintainers and the community understand your report, reproduce the behavior, and find related reports.
Before creating bug reports, please check [this list](#before-submitting-a-bug-report)
as you might find out that you don't need to create one.
When you are creating a bug report, please [include as many details as possible](#how-do-i-submit-a-good-bug-report).
Fill out [the required template](./ISSUE_TEMPLATE/bug_report.md),
the information it asks for helps us resolve issues faster.
> **Note:** If you find a **Closed** issue that seems like it is the same thing that you're experiencing, open a new issue and include a link to the original issue in the body of your new one.
#### Before Submitting A Bug Report
* **Determine [which repository the problem should be reported in](#capa-and-its-repositories)**.
* **Perform a [cursory search](https://github.com/mandiant/capa/issues?q=is%3Aissue)** to see if the problem has already been reported. If it has **and the issue is still open**, add a comment to the existing issue instead of opening a new one.
#### How Do I Submit A (Good) Bug Report?
Bugs are tracked as [GitHub issues](https://guides.github.com/features/issues/).
After you've determined [which repository](#capa-and-its-repositories) your bug is related to,
create an issue on that repository and provide the following information by filling in
[the template](./ISSUE_TEMPLATE/bug_report.md).
Explain the problem and include additional details to help maintainers reproduce the problem:
* **Use a clear and descriptive title** for the issue to identify the problem.
* **Describe the exact steps which reproduce the problem** in as many details as possible. For example, start by explaining how you started capa, e.g. which command exactly you used in the terminal, or how you started capa otherwise.
* **Provide specific examples to demonstrate the steps**. Include links to files or GitHub projects, or copy/pasteable snippets, which you use in those examples. If you're providing snippets in the issue, use [Markdown code blocks](https://help.github.com/articles/markdown-basics/#multiple-lines).
* **Describe the behavior you observed after following the steps** and point out what exactly is the problem with that behavior.
* **Explain which behavior you expected to see instead and why.**
* **Include screenshots and animated GIFs** which show you following the described steps and clearly demonstrate the problem. You can use [this tool](https://www.cockos.com/licecap/) to record GIFs on macOS and Windows, and [this tool](https://github.com/colinkeenan/silentcast) or [this tool](https://github.com/GNOME/byzanz) on Linux.
* **If you're reporting that capa crashed**, include the stack trace from the terminal. Include the stack trace in the issue in a [code block](https://help.github.com/articles/markdown-basics/#multiple-lines), a [file attachment](https://help.github.com/articles/file-attachments-on-issues-and-pull-requests/), or put it in a [gist](https://gist.github.com/) and provide link to that gist.
* **If the problem wasn't triggered by a specific action**, describe what you were doing before the problem happened and share more information using the guidelines below.
Provide more context by answering these questions:
* **Did the problem start happening recently** (e.g. after updating to a new version of capa) or was this always a problem?
* If the problem started happening recently, **can you reproduce the problem in an older version of capa?** What's the most recent version in which the problem doesn't happen? You can download older versions of capa from [the releases page](https://github.com/mandiant/capa/releases).
* **Can you reliably reproduce the issue?** If not, provide details about how often the problem happens and under which conditions it normally happens.
* If the problem is related to working with files (e.g. opening and editing files), **does the problem happen for all files and projects or only some?** Does the problem happen only when working with local or remote files (e.g. on network drives), with files of a specific type (e.g. only JavaScript or Python files), with large files or files with very long lines, or with files in a specific encoding? Is there anything else special about the files you are using?
Include details about your configuration and environment:
* **Which version of capa are you using?** You can get the exact version by running `capa --version` in your terminal.
* **What's the name and version of the OS you're using**?
### Suggesting Enhancements
This section guides you through submitting an enhancement suggestion for capa, including completely new features and minor improvements to existing functionality. Following these guidelines helps maintainers and the community understand your suggestion and find related suggestions.
Before creating enhancement suggestions, please check [this list](#before-submitting-an-enhancement-suggestion) as you might find out that you don't need to create one. When you are creating an enhancement suggestion, please [include as many details as possible](#how-do-i-submit-a-good-enhancement-suggestion). Fill in [the template](./ISSUE_TEMPLATE/feature_request.md), including the steps that you imagine you would take if the feature you're requesting existed.
#### Before Submitting An Enhancement Suggestion
* **Determine [which repository the enhancement should be suggested in](#capa-and-its-repositories).**
* **Perform a [cursory search](https://github.com/mandiant/capa/issues?q=is%3Aissue)** to see if the enhancement has already been suggested. If it has, add a comment to the existing issue instead of opening a new one.
#### How Do I Submit A (Good) Enhancement Suggestion?
Enhancement suggestions are tracked as [GitHub issues](https://guides.github.com/features/issues/). After you've determined [which repository](#capa-and-its-repositories) your enhancement suggestion is related to, create an issue on that repository and provide the following information:
* **Use a clear and descriptive title** for the issue to identify the suggestion.
* **Provide a step-by-step description of the suggested enhancement** in as many details as possible.
* **Provide specific examples to demonstrate the steps**. Include copy/pasteable snippets which you use in those examples, as [Markdown code blocks](https://help.github.com/articles/markdown-basics/#multiple-lines).
* **Describe the current behavior** and **explain which behavior you expected to see instead** and why.
* **Include screenshots and animated GIFs** which help you demonstrate the steps or point out the part of capa which the suggestion is related to. You can use [this tool](https://www.cockos.com/licecap/) to record GIFs on macOS and Windows, and [this tool](https://github.com/colinkeenan/silentcast) or [this tool](https://github.com/GNOME/byzanz) on Linux.
* **Explain why this enhancement would be useful** to most capa users and isn't something that can or should be implemented as an external tool that uses capa as a library.
* **Specify which version of capa you're using.** You can get the exact version by running `capa --version` in your terminal.
* **Specify the name and version of the OS you're using.**
### Your First Code Contribution
Unsure where to begin contributing to capa? You can start by looking through these `good-first-issue` and `rule-idea` issues:
* [good-first-issue](https://github.com/mandiant/capa/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22) - issues which should only require a few lines of code, and a test or two.
* [rule-idea](https://github.com/mandiant/capa-rules/issues?q=is%3Aissue+is%3Aopen+label%3A%22rule+idea%22) - issues that describe potential new rule ideas.
Both issue lists are sorted by total number of comments. While not perfect, number of comments is a reasonable proxy for impact a given change will have.
#### Local development
capa and all its resources can be developed locally.
For instructions on how to do this, see the "Method 3" section of the [installation guide](https://github.com/mandiant/capa/blob/master/doc/installation.md).
### Pull Requests
The process described here has several goals:
- Maintain capa's quality
- Fix problems that are important to users
- Engage the community in working toward the best possible capa
- Enable a sustainable system for capa's maintainers to review contributions
Please follow these steps to have your contribution considered by the maintainers:
0. Sign the [Contributor License Agreement](#contributor-license-agreement)
1. Follow the [styleguides](#styleguides)
2. Update the CHANGELOG and add tests and documentation. In case they are not needed, indicate it in [the PR template](pull_request_template.md).
3. After you submit your pull request, verify that all [status checks](https://help.github.com/articles/about-status-checks/) are passing <details><summary>What if the status checks are failing? </summary>If a status check is failing, and you believe that the failure is unrelated to your change, please leave a comment on the pull request explaining why you believe the failure is unrelated. A maintainer will re-run the status check for you. If we conclude that the failure was a false positive, then we will open an issue to track that problem with our status check suite.</details>
While the prerequisites above must be satisfied prior to having your pull request reviewed, the reviewer(s) may ask you to complete additional design work, tests, or other changes before your pull request can be ultimately accepted.
### Contributor License Agreement
Contributions to this project must be accompanied by a Contributor License
Agreement. You (or your employer) retain the copyright to your contribution,
this simply gives us permission to use and redistribute your contributions as
part of the project. Head over to <https://cla.developers.google.com/> to see
your current agreements on file or to sign a new one.
You generally only need to submit a CLA once, so if you've already submitted one
(even if it was for a different project), you probably don't need to do it
again.
## Styleguides
### Git Commit Messages
* Use the present tense ("Add feature" not "Added feature")
* Use the imperative mood ("Move cursor to..." not "Moves cursor to...")
* Prefix the first line with the component in question ("rules: ..." or "render: ...")
* Reference issues and pull requests liberally after the first line
### Python Styleguide
All Python code must adhere to the style guide used by capa:
1. [PEP8](https://www.python.org/dev/peps/pep-0008/), with clarifications from
2. [Willi's style guide](https://docs.google.com/document/d/1iRpeg-w4DtibwytUyC_dDT7IGhNGBP25-nQfuBa-Fyk/edit?usp=sharing), formatted with
3. [isort](https://pypi.org/project/isort/) (with line width 120 and ordered by line length), and formatted with
4. [black](https://github.com/psf/black) (with line width 120), and formatted with
5. [dos2unix](https://linux.die.net/man/1/dos2unix)
Our CI pipeline will reformat and enforce the Python styleguide.
### Rules Styleguide
All (non-nursery) capa rules must:
1. pass the [linter](https://github.com/mandiant/capa/blob/master/scripts/lint.py), and
2. be formatted with [capafmt](https://github.com/mandiant/capa/blob/master/scripts/capafmt.py)
This ensures that all rules meet the same minimum level of quality and are structured in a consistent way.
Our CI pipeline will reformat and enforce the capa rules styleguide.
# Contributing to Capa
First off, thanks for taking the time to contribute!
The following is a set of guidelines for contributing to capa and its packages, which are hosted in the [FireEye Organization](https://github.com/fireeye) on GitHub. These are mostly guidelines, not rules. Use your best judgment, and feel free to propose changes to this document in a pull request.
#### Table Of Contents
[Code of Conduct](#code-of-conduct)
[What should I know before I get started?](#what-should-i-know-before-i-get-started)
* [Capa and its Repositories](#capa-and-its-repositories)
* [Capa Design Decisions](#design-decisions)
[How Can I Contribute?](#how-can-i-contribute)
* [Reporting Bugs](#reporting-bugs)
* [Suggesting Enhancements](#suggesting-enhancements)
* [Your First Code Contribution](#your-first-code-contribution)
* [Pull Requests](#pull-requests)
[Styleguides](#styleguides)
* [Git Commit Messages](#git-commit-messages)
* [Python Styleguide](#python-styleguide)
* [Rules Styleguide](#rules-styleguide)
## Code of Conduct
This project and everyone participating in it is governed by the [Capa Code of Conduct](CODE_OF_CONDUCT.md). By participating, you are expected to uphold this code. Please report unacceptable behavior to the maintainers.
## What should I know before I get started?
### Capa and its repositories
We host the capa project as three Github repositories:
- [capa](https://github.com/fireeye/capa)
- [capa-rules](https://github.com/fireeye/capa-rules)
- [capa-testfiles](https://github.com/fireeye/capa-testfiles)
The command line tools, logic engine, and other Python source code are found in the `capa` repository.
This is the repository to fork when you want to enhance the features, performance, or user interface of capa.
Do *not* push rules directly to this repository, instead...
The standard rules contributed by the community are found in the `capa-rules` repository.
When you have an idea for a new rule, you should open a PR against `capa-rules`.
We keep `capa` and `capa-rules` separate to distinguish where ideas, bugs, and discussions should happen.
If you're writing yaml it probably goes in `capa-rules` and if you're writing Python it probably goes in `capa`.
Also, we encourage users to develop their own rule repositories, so we treat our default set of rules in the same way.
Test fixtures, such as malware samples and analysis workspaces, are found in the `capa-testfiles` repository.
These are files you'll need in order to run the linter (in `--thorough` mode) and full test suites;
however, they take up a lot of space (1GB+), so by keeping `capa-testfiles` separate,
a shallow checkout of `capa` and `capa-rules` doesn't take much bandwidth.
### Design Decisions
When we make a significant decision in how we maintain the project and what we can or cannot support,
we will document it in the [capa issues tracker](https://github.com/fireeye/capa/issues).
This is the best place review our discussions about what/how/why we do things in the project.
If you have a question, check to see if it is documented there.
If it is *not* documented there, or you can't find an answer, please open a issue.
We'll link to existing issues when appropriate to keep discussions in one place.
## How Can I Contribute?
### Reporting Bugs
This section guides you through submitting a bug report for capa.
Following these guidelines helps maintainers and the community understand your report, reproduce the behavior, and find related reports.
Before creating bug reports, please check [this list](#before-submitting-a-bug-report)
as you might find out that you don't need to create one.
When you are creating a bug report, please [include as many details as possible](#how-do-i-submit-a-good-bug-report).
Fill out [the required template](./ISSUE_TEMPLATE/bug_report.md),
the information it asks for helps us resolve issues faster.
> **Note:** If you find a **Closed** issue that seems like it is the same thing that you're experiencing, open a new issue and include a link to the original issue in the body of your new one.
#### Before Submitting A Bug Report
* **Determine [which repository the problem should be reported in](#capa-and-its-repositories)**.
* **Perform a [cursory search](https://github.com/fireeye/capa/issues?q=is%3Aissue)** to see if the problem has already been reported. If it has **and the issue is still open**, add a comment to the existing issue instead of opening a new one.
#### How Do I Submit A (Good) Bug Report?
Bugs are tracked as [GitHub issues](https://guides.github.com/features/issues/).
After you've determined [which repository](#capa-and-its-repositories) your bug is related to,
create an issue on that repository and provide the following information by filling in
[the template](./ISSUE_TEMPLATE/bug_report.md).
Explain the problem and include additional details to help maintainers reproduce the problem:
* **Use a clear and descriptive title** for the issue to identify the problem.
* **Describe the exact steps which reproduce the problem** in as many details as possible. For example, start by explaining how you started capa, e.g. which command exactly you used in the terminal, or how you started capa otherwise.
* **Provide specific examples to demonstrate the steps**. Include links to files or GitHub projects, or copy/pasteable snippets, which you use in those examples. If you're providing snippets in the issue, use [Markdown code blocks](https://help.github.com/articles/markdown-basics/#multiple-lines).
* **Describe the behavior you observed after following the steps** and point out what exactly is the problem with that behavior.
* **Explain which behavior you expected to see instead and why.**
* **Include screenshots and animated GIFs** which show you following the described steps and clearly demonstrate the problem. You can use [this tool](https://www.cockos.com/licecap/) to record GIFs on macOS and Windows, and [this tool](https://github.com/colinkeenan/silentcast) or [this tool](https://github.com/GNOME/byzanz) on Linux.
* **If you're reporting that capa crashed**, include the stack trace from the terminal. Include the stack trace in the issue in a [code block](https://help.github.com/articles/markdown-basics/#multiple-lines), a [file attachment](https://help.github.com/articles/file-attachments-on-issues-and-pull-requests/), or put it in a [gist](https://gist.github.com/) and provide link to that gist.
* **If the problem wasn't triggered by a specific action**, describe what you were doing before the problem happened and share more information using the guidelines below.
Provide more context by answering these questions:
* **Did the problem start happening recently** (e.g. after updating to a new version of capa) or was this always a problem?
* If the problem started happening recently, **can you reproduce the problem in an older version of capa?** What's the most recent version in which the problem doesn't happen? You can download older versions of capa from [the releases page](https://github.com/fireeye/capa/releases).
* **Can you reliably reproduce the issue?** If not, provide details about how often the problem happens and under which conditions it normally happens.
* If the problem is related to working with files (e.g. opening and editing files), **does the problem happen for all files and projects or only some?** Does the problem happen only when working with local or remote files (e.g. on network drives), with files of a specific type (e.g. only JavaScript or Python files), with large files or files with very long lines, or with files in a specific encoding? Is there anything else special about the files you are using?
Include details about your configuration and environment:
* **Which version of capa are you using?** You can get the exact version by running `capa --version` in your terminal.
* **What's the name and version of the OS you're using**?
### Suggesting Enhancements
This section guides you through submitting an enhancement suggestion for capa, including completely new features and minor improvements to existing functionality. Following these guidelines helps maintainers and the community understand your suggestion and find related suggestions.
Before creating enhancement suggestions, please check [this list](#before-submitting-an-enhancement-suggestion) as you might find out that you don't need to create one. When you are creating an enhancement suggestion, please [include as many details as possible](#how-do-i-submit-a-good-enhancement-suggestion). Fill in [the template](./ISSUE_TEMPLATE/feature_request.md), including the steps that you imagine you would take if the feature you're requesting existed.
#### Before Submitting An Enhancement Suggestion
* **Determine [which repository the enhancement should be suggested in](#capa-and-its-repositories).**
* **Perform a [cursory search](https://github.com/fireeye/capa/issues?q=is%3Aissue)** to see if the enhancement has already been suggested. If it has, add a comment to the existing issue instead of opening a new one.
#### How Do I Submit A (Good) Enhancement Suggestion?
Enhancement suggestions are tracked as [GitHub issues](https://guides.github.com/features/issues/). After you've determined [which repository](#capa-and-its-repositories) your enhancement suggestion is related to, create an issue on that repository and provide the following information:
* **Use a clear and descriptive title** for the issue to identify the suggestion.
* **Provide a step-by-step description of the suggested enhancement** in as many details as possible.
* **Provide specific examples to demonstrate the steps**. Include copy/pasteable snippets which you use in those examples, as [Markdown code blocks](https://help.github.com/articles/markdown-basics/#multiple-lines).
* **Describe the current behavior** and **explain which behavior you expected to see instead** and why.
* **Include screenshots and animated GIFs** which help you demonstrate the steps or point out the part of capa which the suggestion is related to. You can use [this tool](https://www.cockos.com/licecap/) to record GIFs on macOS and Windows, and [this tool](https://github.com/colinkeenan/silentcast) or [this tool](https://github.com/GNOME/byzanz) on Linux.
* **Explain why this enhancement would be useful** to most capa users and isn't something that can or should be implemented as an external tool that uses capa as a library.
* **Specify which version of capa you're using.** You can get the exact version by running `capa --version` in your terminal.
* **Specify the name and version of the OS you're using.**
### Your First Code Contribution
Unsure where to begin contributing to capa? You can start by looking through these `good-first-issue` and `rule-idea` issues:
* [good-first-issue](https://github.com/fireeye/capa/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22) - issues which should only require a few lines of code, and a test or two.
* [rule-idea](https://github.com/fireeye/capa-rules/issues?q=is%3Aissue+is%3Aopen+label%3A%22rule+idea%22) - issues that describe potential new rule ideas.
Both issue lists are sorted by total number of comments. While not perfect, number of comments is a reasonable proxy for impact a given change will have.
#### Local development
capa and all its resources can be developed locally.
For instructions on how to do this, see the "Method 3" section of the [installation guide](https://github.com/fireeye/capa/blob/master/doc/installation.md).
### Pull Requests
The process described here has several goals:
- Maintain capa's quality
- Fix problems that are important to users
- Engage the community in working toward the best possible capa
- Enable a sustainable system for capa's maintainers to review contributions
Please follow these steps to have your contribution considered by the maintainers:
1. Follow all instructions in [the template](PULL_REQUEST_TEMPLATE.md)
2. Follow the [styleguides](#styleguides)
3. After you submit your pull request, verify that all [status checks](https://help.github.com/articles/about-status-checks/) are passing <details><summary>What if the status checks are failing? </summary>If a status check is failing, and you believe that the failure is unrelated to your change, please leave a comment on the pull request explaining why you believe the failure is unrelated. A maintainer will re-run the status check for you. If we conclude that the failure was a false positive, then we will open an issue to track that problem with our status check suite.</details>
While the prerequisites above must be satisfied prior to having your pull request reviewed, the reviewer(s) may ask you to complete additional design work, tests, or other changes before your pull request can be ultimately accepted.
## Styleguides
### Git Commit Messages
* Use the present tense ("Add feature" not "Added feature")
* Use the imperative mood ("Move cursor to..." not "Moves cursor to...")
* Prefix the first line with the component in question ("rules: ..." or "render: ...")
* Reference issues and pull requests liberally after the first line
### Python Styleguide
All Python code must adhere to the style guide used by capa:
1. [PEP8](https://www.python.org/dev/peps/pep-0008/), with clarifications from
2. [Willi's style guide](https://docs.google.com/document/d/1iRpeg-w4DtibwytUyC_dDT7IGhNGBP25-nQfuBa-Fyk/edit?usp=sharing), formatted with
3. [isort](https://pypi.org/project/isort/) (with line width 120 and ordered by line length), and formatted with
4. [black](https://github.com/psf/black) (with line width 120), and formatted with
5. [dos2unix](https://linux.die.net/man/1/dos2unix)
Our CI pipeline will reformat and enforce the Python styleguide.
### Rules Styleguide
All (non-nursery) capa rules must:
1. pass the [linter](https://github.com/fireeye/capa/blob/master/scripts/lint.py), and
2. be formatted with [capafmt](https://github.com/fireeye/capa/blob/master/scripts/capafmt.py)
This ensures that all rules meet the same minimum level of quality and are structured in a consistent way.
Our CI pipeline will reformat and enforce the capa rules styleguide.

View File

@@ -1,47 +1,47 @@
---
name: Bug report
about: Create a report to help us improve
---
<!--
# Is your bug report related to capa rules (for example a false positive)?
We use submodules to separate code, rules and test data. If your issue is related to capa rules, please report it at https://github.com/mandiant/capa-rules/issues.
# Have you checked that your issue isn't already filed?
Please search if there is a similar issue at https://github.com/mandiant/capa/issues. If there is already a similar issue, please add more details there instead of opening a new one.
# Have you read capa's Code of Conduct?
By filing an Issue, you are expected to comply with it, including treating everyone with respect: https://github.com/mandiant/capa/blob/master/.github/CODE_OF_CONDUCT.md
# Have you read capa's CONTRIBUTING guide?
It contains helpful information about how to contribute to capa. Check https://github.com/mandiant/capa/blob/master/.github/CONTRIBUTING.md#reporting-bugs
-->
### Description
<!-- Description of the issue -->
### Steps to Reproduce
<!-- 1. First Step -->
<!-- 2. Second Step -->
<!-- 3. and so on… -->
**Expected behavior:**
<!-- What you expect to happen -->
**Actual behavior:**
<!-- What actually happens -->
### Versions
<!-- You can get this information from copy and pasting the output of `capa --version` from the command line.
Please specify the component you're using (e.g. standalone tool or IDA Pro integration) and your Python version.
Also, please include the OS and what version of the OS you're running. -->
### Additional Information
<!-- Any additional information, configuration or data that might be necessary to reproduce the issue. -->
---
name: Bug report
about: Create a report to help us improve
---
<!--
# Is your bug report related to capa rules (for example a false positive)?
We use sybmodules to separate code, rules and test data. If your issue is related to capa rules, please report it at https://github.com/fireeye/capa-rules/issues.
# Have you checked that your issue isn't already filed?
Please search if there is a similar issue at https://github.com/fireeye/capa/issues. If there is already a similar issue, please add more details there instead of opening a new one.
# Have you read capa's Code of Conduct?
By filing an Issue, you are expected to comply with it, including treating everyone with respect: https://github.com/fireeye/capa/blob/master/.github/CODE_OF_CONDUCT.md
# Have you read capa's CONTRIBUTING guide?
It contains helpful information about how to contribute to capa. Check https://github.com/fireeye/capa/blob/master/.github/CONTRIBUTING.md#reporting-bugs
-->
### Description
<!-- Description of the issue -->
### Steps to Reproduce
<!-- 1. First Step -->
<!-- 2. Second Step -->
<!-- 3. and so on… -->
**Expected behavior:**
<!-- What you expect to happen -->
**Actual behavior:**
<!-- What actually happens -->
### Versions
<!-- You can get this information from copy and pasting the output of `capa --version` from the command line.
Please specify the component you're using (e.g. standalone tool or IDA Pro integration) and your Python version.
Also, please include the OS and what version of the OS you're running. -->
### Additional Information
<!-- Any additional information, configuration or data that might be necessary to reproduce the issue. -->

View File

@@ -1,35 +1,35 @@
---
name: Feature request
about: Suggest an idea for capa
---
<!--
# Is your issue related to capa rules (for example an idea for a new rule)?
We use submodules to separate code, rules and test data. If your issue is related to capa rules, please report it at https://github.com/mandiant/capa-rules/issues.
# Have you checked that your issue isn't already filed?
Please search if there is a similar issue at https://github.com/mandiant/capa/issues. If there is already a similar issue, please add more details there instead of opening a new one.
# Have you read capa's Code of Conduct?
By filing an Issue, you are expected to comply with it, including treating everyone with respect: https://github.com/mandiant/capa/blob/master/.github/CODE_OF_CONDUCT.md
# Have you read capa's CONTRIBUTING guide?
It contains helpful information about how to contribute to capa. Check https://github.com/mandiant/capa/blob/master/.github/CONTRIBUTING.md#suggesting-enhancements
-->
### Summary
<!-- One paragraph explanation of the feature. -->
### Motivation
<!-- Why are we doing this? What use cases does it support? What is the expected outcome? -->
### Describe alternatives you've considered
<!-- A clear and concise description of the alternative solutions you've considered. -->
## Additional context
<!-- Add any other context or screenshots about the feature request here. -->
---
name: Feature request
about: Suggest an idea for capa
---
<!--
# Is your issue related to capa rules (for example an idea for a new rule)?
We use sybmodules to separate code, rules and test data. If your issue is related to capa rules, please report it at https://github.com/fireeye/capa-rules/issues.
# Have you checked that your issue isn't already filed?
Please search if there is a similar issue at https://github.com/fireeye/capa/issues. If there is already a similar issue, please add more details there instead of opening a new one.
# Have you read capa's Code of Conduct?
By filing an Issue, you are expected to comply with it, including treating everyone with respect: https://github.com/fireeye/capa/blob/master/.github/CODE_OF_CONDUCT.md
# Have you read capa's CONTRIBUTING guide?
It contains helpful information about how to contribute to capa. Check https://github.com/fireeye/capa/blob/master/.github/CONTRIBUTING.md#suggesting-enhancements
-->
### Summary
<!-- One paragraph explanation of the feature. -->
### Motivation
<!-- Why are we doing this? What use cases does it support? What is the expected outcome? -->
### Describe alternatives you've considered
<!-- A clear and concise description of the alternative solutions you've considered. -->
## Additional context
<!-- Add any other context or screenshots about the feature request here. -->

43
.github/flake8.ini vendored
View File

@@ -1,43 +0,0 @@
[flake8]
max-line-length = 120
extend-ignore =
# E203: whitespace before ':' (black does this)
E203,
# F401: `foo` imported but unused (prefer ruff)
F401,
# F811 Redefinition of unused `foo` (prefer ruff)
F811,
# E501 line too long (prefer black)
E501,
# E701 multiple statements on one line (colon) (prefer black, see https://github.com/psf/black/issues/4173)
E701,
# B010 Do not call setattr with a constant attribute value
B010,
# G200 Logging statement uses exception in arguments
G200,
# SIM102 Use a single if-statement instead of nested if-statements
# doesn't provide a space for commenting or logical separation of conditions
SIM102,
# SIM114 Use logical or and a single body
# makes logic trees too complex
SIM114,
# SIM117 Use 'with Foo, Bar:' instead of multiple with statements
# makes lines too long
SIM117
per-file-ignores =
# T201 print found.
#
# scripts are meant to print output
scripts/*: T201
# capa.exe is meant to print output
capa/main.py: T201
# IDA tests emit results to output window so need to print
tests/test_ida_features.py: T201
# utility used to find the Binary Ninja API via invoking python.exe
capa/features/extractors/binja/find_binja_api.py: T201
copyright-check = True
copyright-min-file-size = 1
copyright-regexp = Copyright \(C\) 2023 Mandiant, Inc. All Rights Reserved.

91
.github/mypy/mypy.ini vendored
View File

@@ -1,91 +0,0 @@
[mypy]
[mypy-halo.*]
ignore_missing_imports = True
[mypy-tqdm.*]
ignore_missing_imports = True
[mypy-ruamel.*]
ignore_missing_imports = True
[mypy-networkx.*]
ignore_missing_imports = True
[mypy-pefile.*]
ignore_missing_imports = True
[mypy-viv_utils.*]
ignore_missing_imports = True
[mypy-flirt.*]
ignore_missing_imports = True
[mypy-lief.*]
ignore_missing_imports = True
[mypy-idc.*]
ignore_missing_imports = True
[mypy-vivisect.*]
ignore_missing_imports = True
[mypy-envi.*]
ignore_missing_imports = True
[mypy-PE.*]
ignore_missing_imports = True
[mypy-idaapi.*]
ignore_missing_imports = True
[mypy-idautils.*]
ignore_missing_imports = True
[mypy-ida_auto.*]
ignore_missing_imports = True
[mypy-ida_bytes.*]
ignore_missing_imports = True
[mypy-ida_nalt.*]
ignore_missing_imports = True
[mypy-ida_kernwin.*]
ignore_missing_imports = True
[mypy-ida_settings.*]
ignore_missing_imports = True
[mypy-ida_funcs.*]
ignore_missing_imports = True
[mypy-ida_loader.*]
ignore_missing_imports = True
[mypy-ida_segment.*]
ignore_missing_imports = True
[mypy-PyQt5.*]
ignore_missing_imports = True
[mypy-binaryninja.*]
ignore_missing_imports = True
[mypy-pytest.*]
ignore_missing_imports = True
[mypy-devtools.*]
ignore_missing_imports = True
[mypy-elftools.*]
ignore_missing_imports = True
[mypy-dncil.*]
ignore_missing_imports = True
[mypy-netnode.*]
ignore_missing_imports = True
[mypy-ghidra.*]
ignore_missing_imports = True

View File

@@ -1,22 +0,0 @@
<!--
Thank you for contributing to capa! <3
Please read capa's CONTRIBUTING guide if you haven't done so already.
It contains helpful information about how to contribute to capa. Check https://github.com/mandiant/capa/blob/master/.github/CONTRIBUTING.md
Please describe the changes in this pull request (PR). Include your motivation and context to help us review.
Please mention the issue your PR addresses (if any):
closes #issue_number
-->
### Checklist
<!-- CHANGELOG.md has a `master (unreleased)` section. Please add bug fixes, new features, breaking changes and anything else you think is worthwhile mentioning in the release notes to this file. -->
- [ ] No CHANGELOG update needed
<!-- Tests prove that your fix/work as expected and ensure it doesn't break on the feature. -->
- [ ] No new tests needed
<!-- Please help us keeping capa documentation up-to-date -->
- [ ] No documentation update needed

View File

@@ -1,4 +1,4 @@
# Copyright (C) 2020 Mandiant, Inc. All Rights Reserved.
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
from PyInstaller.utils.hooks import copy_metadata
@@ -13,173 +13,3 @@ from PyInstaller.utils.hooks import copy_metadata
#
# ref: https://github.com/pyinstaller/pyinstaller/issues/1713#issuecomment-162682084
datas = copy_metadata("vivisect")
excludedimports = [
# viv gui requires these heavy libraries,
# but viv as a library doesn't.
# they shouldn't be installed in our configuration,
# but we'll ensure they don't slip in here (such as on developers' systems).
"PyQt5",
"qt5",
"pyqtwebengine",
# the above are imported by these viv modules.
# so really, we'd want to exclude these submodules of viv.
# but i dont think this works.
"vqt",
"vdb.qt",
"envi.qt",
# unused by capa
"pyasn1",
]
hiddenimports = [
# vivisect does manual/runtime importing of its modules,
# so declare the things that could be imported here.
"vivisect",
"vivisect.analysis",
"vivisect.analysis.amd64",
"vivisect.analysis.amd64.emulation",
"vivisect.analysis.amd64.golang",
"vivisect.analysis.crypto",
"vivisect.analysis.crypto.constants",
"vivisect.analysis.elf",
"vivisect.analysis.elf.elfplt",
"vivisect.analysis.elf.elfplt_late",
"vivisect.analysis.elf.libc_start_main",
"vivisect.analysis.generic",
"vivisect.analysis.generic.codeblocks",
"vivisect.analysis.generic.emucode",
"vivisect.analysis.generic.entrypoints",
"vivisect.analysis.generic.funcentries",
"vivisect.analysis.generic.impapi",
"vivisect.analysis.generic.linker",
"vivisect.analysis.generic.mkpointers",
"vivisect.analysis.generic.noret",
"vivisect.analysis.generic.pointers",
"vivisect.analysis.generic.pointertables",
"vivisect.analysis.generic.relocations",
"vivisect.analysis.generic.strconst",
"vivisect.analysis.generic.switchcase",
"vivisect.analysis.generic.symswitchcase",
"vivisect.analysis.generic.thunks",
"vivisect.analysis.i386",
"vivisect.analysis.i386.calling",
"vivisect.analysis.i386.golang",
"vivisect.analysis.i386.importcalls",
"vivisect.analysis.i386.instrhook",
"vivisect.analysis.i386.thunk_reg",
"vivisect.analysis.ms",
"vivisect.analysis.ms.hotpatch",
"vivisect.analysis.ms.localhints",
"vivisect.analysis.ms.msvc",
"vivisect.analysis.ms.msvcfunc",
"vivisect.analysis.ms.vftables",
"vivisect.analysis.pe",
"vivisect.impapi.posix.amd64",
"vivisect.impapi.posix.i386",
"vivisect.impapi.windows",
"vivisect.impapi.windows.advapi_32",
"vivisect.impapi.windows.advapi_64",
"vivisect.impapi.windows.amd64",
"vivisect.impapi.windows.gdi_32",
"vivisect.impapi.windows.gdi_64",
"vivisect.impapi.windows.i386",
"vivisect.impapi.windows.kernel_32",
"vivisect.impapi.windows.kernel_64",
"vivisect.impapi.windows.msvcr100_32",
"vivisect.impapi.windows.msvcr100_64",
"vivisect.impapi.windows.msvcr110_32",
"vivisect.impapi.windows.msvcr110_64",
"vivisect.impapi.windows.msvcr120_32",
"vivisect.impapi.windows.msvcr120_64",
"vivisect.impapi.windows.msvcr71_32",
"vivisect.impapi.windows.msvcr80_32",
"vivisect.impapi.windows.msvcr80_64",
"vivisect.impapi.windows.msvcr90_32",
"vivisect.impapi.windows.msvcr90_64",
"vivisect.impapi.windows.msvcrt_32",
"vivisect.impapi.windows.msvcrt_64",
"vivisect.impapi.windows.ntdll_32",
"vivisect.impapi.windows.ntdll_64",
"vivisect.impapi.windows.ole_32",
"vivisect.impapi.windows.ole_64",
"vivisect.impapi.windows.rpcrt4_32",
"vivisect.impapi.windows.rpcrt4_64",
"vivisect.impapi.windows.shell_32",
"vivisect.impapi.windows.shell_64",
"vivisect.impapi.windows.user_32",
"vivisect.impapi.windows.user_64",
"vivisect.impapi.windows.ws2plus_32",
"vivisect.impapi.windows.ws2plus_64",
"vivisect.impapi.winkern",
"vivisect.impapi.winkern.i386",
"vivisect.impapi.winkern.amd64",
"vivisect.parsers.blob",
"vivisect.parsers.elf",
"vivisect.parsers.ihex",
"vivisect.parsers.macho",
"vivisect.parsers.pe",
"vivisect.storage",
"vivisect.storage.basicfile",
"vstruct.constants",
"vstruct.constants.ntstatus",
"vstruct.defs",
"vstruct.defs.arm7",
"vstruct.defs.bmp",
"vstruct.defs.dns",
"vstruct.defs.elf",
"vstruct.defs.gif",
"vstruct.defs.ihex",
"vstruct.defs.inet",
"vstruct.defs.java",
"vstruct.defs.kdcom",
"vstruct.defs.macho",
"vstruct.defs.macho.const",
"vstruct.defs.macho.fat",
"vstruct.defs.macho.loader",
"vstruct.defs.macho.stabs",
"vstruct.defs.minidump",
"vstruct.defs.pcap",
"vstruct.defs.pe",
"vstruct.defs.pptp",
"vstruct.defs.rar",
"vstruct.defs.swf",
"vstruct.defs.win32",
"vstruct.defs.windows",
"vstruct.defs.windows.win_5_1_i386",
"vstruct.defs.windows.win_5_1_i386.ntdll",
"vstruct.defs.windows.win_5_1_i386.ntoskrnl",
"vstruct.defs.windows.win_5_1_i386.win32k",
"vstruct.defs.windows.win_5_2_i386",
"vstruct.defs.windows.win_5_2_i386.ntdll",
"vstruct.defs.windows.win_5_2_i386.ntoskrnl",
"vstruct.defs.windows.win_5_2_i386.win32k",
"vstruct.defs.windows.win_6_1_amd64",
"vstruct.defs.windows.win_6_1_amd64.ntdll",
"vstruct.defs.windows.win_6_1_amd64.ntoskrnl",
"vstruct.defs.windows.win_6_1_amd64.win32k",
"vstruct.defs.windows.win_6_1_i386",
"vstruct.defs.windows.win_6_1_i386.ntdll",
"vstruct.defs.windows.win_6_1_i386.ntoskrnl",
"vstruct.defs.windows.win_6_1_i386.win32k",
"vstruct.defs.windows.win_6_1_wow64",
"vstruct.defs.windows.win_6_1_wow64.ntdll",
"vstruct.defs.windows.win_6_2_amd64",
"vstruct.defs.windows.win_6_2_amd64.ntdll",
"vstruct.defs.windows.win_6_2_amd64.ntoskrnl",
"vstruct.defs.windows.win_6_2_amd64.win32k",
"vstruct.defs.windows.win_6_2_i386",
"vstruct.defs.windows.win_6_2_i386.ntdll",
"vstruct.defs.windows.win_6_2_i386.ntoskrnl",
"vstruct.defs.windows.win_6_2_i386.win32k",
"vstruct.defs.windows.win_6_2_wow64",
"vstruct.defs.windows.win_6_2_wow64.ntdll",
"vstruct.defs.windows.win_6_3_amd64",
"vstruct.defs.windows.win_6_3_amd64.ntdll",
"vstruct.defs.windows.win_6_3_amd64.ntoskrnl",
"vstruct.defs.windows.win_6_3_i386",
"vstruct.defs.windows.win_6_3_i386.ntdll",
"vstruct.defs.windows.win_6_3_i386.ntoskrnl",
"vstruct.defs.windows.win_6_3_wow64",
"vstruct.defs.windows.win_6_3_wow64.ntdll",
]

View File

@@ -1,40 +1,176 @@
# -*- mode: python -*-
# Copyright (C) 2020 Mandiant, Inc. All Rights Reserved.
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
import os.path
import subprocess
import wcwidth
# when invoking pyinstaller from the project root,
# this gets run from the project root.
with open('./capa/version.py', 'wb') as f:
# git output will look like:
#
# tags/v1.0.0-0-g3af38dc
# ------- tag
# - commits since
# g------- git hash fragment
version = (subprocess.check_output(["git", "describe", "--always", "--tags", "--long"])
.strip()
.replace("tags/", ""))
f.write("__version__ = '%s'" % version)
a = Analysis(
# when invoking pyinstaller from the project root,
# this gets invoked from the directory of the spec file,
# i.e. ./.github/pyinstaller
["../../capa/main.py"],
pathex=["capa"],
['../../capa/main.py'],
pathex=['capa'],
binaries=None,
datas=[
# when invoking pyinstaller from the project root,
# this gets invoked from the directory of the spec file,
# i.e. ./.github/pyinstaller
("../../rules", "rules"),
("../../sigs", "sigs"),
("../../cache", "cache"),
('../../rules', 'rules'),
# capa.render.default uses tabulate that depends on wcwidth.
# it seems wcwidth uses a json file `version.json`
# and this doesn't get picked up by pyinstaller automatically.
# so we manually embed the wcwidth resources here.
#
# ref: https://stackoverflow.com/a/62278462/87207
(os.path.dirname(wcwidth.__file__), "wcwidth"),
(os.path.dirname(wcwidth.__file__), 'wcwidth')
],
hiddenimports=[
# vivisect does manual/runtime importing of its modules,
# so declare the things that could be imported here.
"vivisect",
"vivisect.analysis",
"vivisect.analysis.amd64",
"vivisect.analysis.amd64",
"vivisect.analysis.amd64.emulation",
"vivisect.analysis.amd64.golang",
"vivisect.analysis.crypto",
"vivisect.analysis.crypto",
"vivisect.analysis.crypto.constants",
"vivisect.analysis.elf",
"vivisect.analysis.elf",
"vivisect.analysis.elf.elfplt",
"vivisect.analysis.elf.libc_start_main",
"vivisect.analysis.generic",
"vivisect.analysis.generic",
"vivisect.analysis.generic.codeblocks",
"vivisect.analysis.generic.emucode",
"vivisect.analysis.generic.entrypoints",
"vivisect.analysis.generic.funcentries",
"vivisect.analysis.generic.impapi",
"vivisect.analysis.generic.mkpointers",
"vivisect.analysis.generic.pointers",
"vivisect.analysis.generic.pointertables",
"vivisect.analysis.generic.relocations",
"vivisect.analysis.generic.strconst",
"vivisect.analysis.generic.switchcase",
"vivisect.analysis.generic.thunks",
"vivisect.analysis.i386",
"vivisect.analysis.i386",
"vivisect.analysis.i386.calling",
"vivisect.analysis.i386.golang",
"vivisect.analysis.i386.importcalls",
"vivisect.analysis.i386.instrhook",
"vivisect.analysis.i386.thunk_bx",
"vivisect.analysis.ms",
"vivisect.analysis.ms",
"vivisect.analysis.ms.hotpatch",
"vivisect.analysis.ms.localhints",
"vivisect.analysis.ms.msvc",
"vivisect.analysis.ms.msvcfunc",
"vivisect.analysis.ms.vftables",
"vivisect.analysis.pe",
"vivisect.impapi.posix.amd64",
"vivisect.impapi.posix.i386",
"vivisect.impapi.windows",
"vivisect.impapi.windows.amd64",
"vivisect.impapi.windows.i386",
"vivisect.impapi.winkern.i386",
"vivisect.impapi.winkern.amd64",
"vivisect.parsers.blob",
"vivisect.parsers.elf",
"vivisect.parsers.ihex",
"vivisect.parsers.macho",
"vivisect.parsers.pe",
"vivisect.parsers.utils",
"vivisect.storage",
"vivisect.storage.basicfile",
"vstruct.constants",
"vstruct.constants.ntstatus",
"vstruct.defs",
"vstruct.defs.arm7",
"vstruct.defs.bmp",
"vstruct.defs.dns",
"vstruct.defs.elf",
"vstruct.defs.gif",
"vstruct.defs.ihex",
"vstruct.defs.inet",
"vstruct.defs.java",
"vstruct.defs.kdcom",
"vstruct.defs.macho",
"vstruct.defs.macho.const",
"vstruct.defs.macho.fat",
"vstruct.defs.macho.loader",
"vstruct.defs.macho.stabs",
"vstruct.defs.minidump",
"vstruct.defs.pcap",
"vstruct.defs.pe",
"vstruct.defs.pptp",
"vstruct.defs.rar",
"vstruct.defs.swf",
"vstruct.defs.win32",
"vstruct.defs.windows",
"vstruct.defs.windows.win_5_1_i386",
"vstruct.defs.windows.win_5_1_i386.ntdll",
"vstruct.defs.windows.win_5_1_i386.ntoskrnl",
"vstruct.defs.windows.win_5_1_i386.win32k",
"vstruct.defs.windows.win_5_2_i386",
"vstruct.defs.windows.win_5_2_i386.ntdll",
"vstruct.defs.windows.win_5_2_i386.ntoskrnl",
"vstruct.defs.windows.win_5_2_i386.win32k",
"vstruct.defs.windows.win_6_1_amd64",
"vstruct.defs.windows.win_6_1_amd64.ntdll",
"vstruct.defs.windows.win_6_1_amd64.ntoskrnl",
"vstruct.defs.windows.win_6_1_amd64.win32k",
"vstruct.defs.windows.win_6_1_i386",
"vstruct.defs.windows.win_6_1_i386.ntdll",
"vstruct.defs.windows.win_6_1_i386.ntoskrnl",
"vstruct.defs.windows.win_6_1_i386.win32k",
"vstruct.defs.windows.win_6_1_wow64",
"vstruct.defs.windows.win_6_1_wow64.ntdll",
"vstruct.defs.windows.win_6_2_amd64",
"vstruct.defs.windows.win_6_2_amd64.ntdll",
"vstruct.defs.windows.win_6_2_amd64.ntoskrnl",
"vstruct.defs.windows.win_6_2_amd64.win32k",
"vstruct.defs.windows.win_6_2_i386",
"vstruct.defs.windows.win_6_2_i386.ntdll",
"vstruct.defs.windows.win_6_2_i386.ntoskrnl",
"vstruct.defs.windows.win_6_2_i386.win32k",
"vstruct.defs.windows.win_6_2_wow64",
"vstruct.defs.windows.win_6_2_wow64.ntdll",
"vstruct.defs.windows.win_6_3_amd64",
"vstruct.defs.windows.win_6_3_amd64.ntdll",
"vstruct.defs.windows.win_6_3_amd64.ntoskrnl",
"vstruct.defs.windows.win_6_3_i386",
"vstruct.defs.windows.win_6_3_i386.ntdll",
"vstruct.defs.windows.win_6_3_i386.ntoskrnl",
"vstruct.defs.windows.win_6_3_wow64",
"vstruct.defs.windows.win_6_3_wow64.ntdll",
],
# when invoking pyinstaller from the project root,
# this gets run from the project root.
hookspath=[".github/pyinstaller/hooks"],
hookspath=['.github/pyinstaller/hooks'],
runtime_hooks=None,
excludes=[
# ignore packages that would otherwise be bundled with the .exe.
# review: build/pyinstaller/xref-pyinstaller.html
# we don't do any GUI stuff, so ignore these modules
"tkinter",
"_tkinter",
@@ -44,52 +180,35 @@ a = Analysis(
# since we don't spawn a notebook, we can safely remove these.
"IPython",
"ipywidgets",
# these are pulled in by networkx
# but we don't need to compute the strongly connected components.
"numpy",
"scipy",
"matplotlib",
"pandas",
"pytest",
# deps from viv that we don't use.
# this duplicates the entries in `hook-vivisect`,
# but works better this way.
"vqt",
"vdb.qt",
"envi.qt",
"PyQt5",
"qt5",
"pyqtwebengine",
"pyasn1",
"binaryninja",
],
)
])
a.binaries = a.binaries - TOC([("tcl85.dll", None, None), ("tk85.dll", None, None), ("_tkinter", None, None)])
a.binaries = a.binaries - TOC([
('tcl85.dll', None, None),
('tk85.dll', None, None),
('_tkinter', None, None)])
pyz = PYZ(a.pure, a.zipped_data)
exe = EXE(
pyz,
a.scripts,
a.binaries,
a.zipfiles,
a.datas,
exclude_binaries=False,
name="capa",
icon="logo.ico",
debug=False,
strip=False,
upx=True,
console=True,
)
exe = EXE(pyz,
a.scripts,
a.binaries,
a.zipfiles,
a.datas,
exclude_binaries=False,
name='capa',
icon='logo.ico',
debug=False,
strip=None,
upx=True,
console=True )
# enable the following to debug the contents of the .exe
#
# coll = COLLECT(exe,
#coll = COLLECT(exe,
# a.binaries,
# a.zipfiles,
# a.datas,
# strip=None,
# upx=True,
# name='capa-dat')

43
.github/ruff.toml vendored
View File

@@ -1,43 +0,0 @@
# Enable the pycodestyle (`E`) and Pyflakes (`F`) rules by default.
# Unlike Flake8, Ruff doesn't enable pycodestyle warnings (`W`) or
# McCabe complexity (`C901`) by default.
select = ["E", "F"]
# Allow autofix for all enabled rules (when `--fix`) is provided.
fixable = ["ALL"]
unfixable = []
# E402 module level import not at top of file
# E722 do not use bare 'except'
# E501 line too long
ignore = ["E402", "E722", "E501"]
line-length = 120
exclude = [
# Exclude a variety of commonly ignored directories.
".bzr",
".direnv",
".eggs",
".git",
".git-rewrite",
".hg",
".mypy_cache",
".nox",
".pants.d",
".pytype",
".ruff_cache",
".svn",
".tox",
".venv",
"__pypackages__",
"_build",
"buck-out",
"build",
"dist",
"node_modules",
"venv",
# protobuf generated files
"*_pb2.py",
"*_pb2.pyi"
]

10
.github/tox.ini vendored Normal file
View File

@@ -0,0 +1,10 @@
[pycodestyle]
; E402: module level import not at top of file
; W503: line break before binary operator
; E231 missing whitespace after ',' (emitted by black)
; E203 whitespace before ':' (emitted by black)
ignore = E402,W503,E203,E231
max-line-length = 160
statistics = True
count = True
exclude = .*

View File

@@ -1,135 +1,82 @@
name: build
on:
pull_request:
branches: [ master ]
release:
types: [edited, published]
permissions:
contents: write
jobs:
build:
name: PyInstaller for ${{ matrix.os }} / Py ${{ matrix.python_version }}
runs-on: ${{ matrix.os }}
strategy:
# set to false for debugging
fail-fast: true
matrix:
# using Python 3.8 to support running across multiple operating systems including Windows 7
include:
- os: ubuntu-20.04
# use old linux so that the shared library versioning is more portable
artifact_name: capa
asset_name: linux
python_version: 3.8
- os: ubuntu-20.04
artifact_name: capa
asset_name: linux-py311
python_version: 3.11
- os: windows-2019
artifact_name: capa.exe
asset_name: windows
python_version: 3.8
- os: macos-11
# use older macOS for assumed better portability
artifact_name: capa
asset_name: macos
python_version: 3.8
steps:
- name: Checkout capa
uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
with:
submodules: true
- name: Set up Python ${{ matrix.python_version }}
uses: actions/setup-python@d27e3f3d7c64b4bbf8e4abfb9b63b83e846e0435 # v4.5.0
with:
python-version: ${{ matrix.python_version }}
- if: matrix.os == 'ubuntu-20.04'
run: sudo apt-get install -y libyaml-dev
- name: Upgrade pip, setuptools
run: python -m pip install --upgrade pip setuptools
- name: Install capa with build requirements
run: pip install -e .[build]
- name: Cache the rule set
run: python ./scripts/cache-ruleset.py ./rules/ ./cache/
- name: Build standalone executable
run: pyinstaller --log-level DEBUG .github/pyinstaller/pyinstaller.spec
- name: Does it run (PE)?
run: dist/capa -d "tests/data/Practical Malware Analysis Lab 01-01.dll_"
- name: Does it run (Shellcode)?
run: dist/capa -d "tests/data/499c2a85f6e8142c3f48d4251c9c7cd6.raw32"
- name: Does it run (ELF)?
run: dist/capa -d "tests/data/7351f8a40c5450557b24622417fc478d.elf_"
- name: Does it run (CAPE)?
run: |
7z e "tests/data/dynamic/cape/v2.2/d46900384c78863420fb3e297d0a2f743cd2b6b3f7f82bf64059a168e07aceb7.json.gz"
dist/capa -d "d46900384c78863420fb3e297d0a2f743cd2b6b3f7f82bf64059a168e07aceb7.json"
- uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
with:
name: ${{ matrix.asset_name }}
path: dist/${{ matrix.artifact_name }}
test_run:
name: Test run on ${{ matrix.os }} / ${{ matrix.asset_name }}
runs-on: ${{ matrix.os }}
needs: [build]
strategy:
matrix:
include:
# OSs not already tested above
- os: ubuntu-22.04
artifact_name: capa
asset_name: linux
- os: ubuntu-22.04
artifact_name: capa
asset_name: linux-py311
- os: windows-2022
artifact_name: capa.exe
asset_name: windows
steps:
- name: Download ${{ matrix.asset_name }}
uses: actions/download-artifact@9bc31d5ccc31df68ecc42ccf4149144866c47d8a # v3.0.2
with:
name: ${{ matrix.asset_name }}
- name: Set executable flag
if: matrix.os != 'windows-2022'
run: chmod +x ${{ matrix.artifact_name }}
- name: Run capa
run: ./${{ matrix.artifact_name }} -h
zip_and_upload:
# upload zipped binaries to Release page
if: github.event_name == 'release'
name: zip and upload ${{ matrix.asset_name }}
runs-on: ubuntu-20.04
needs: [build]
strategy:
matrix:
include:
- asset_name: linux
artifact_name: capa
- asset_name: linux-py311
artifact_name: capa
- asset_name: windows
artifact_name: capa.exe
- asset_name: macos
artifact_name: capa
steps:
- name: Download ${{ matrix.asset_name }}
uses: actions/download-artifact@9bc31d5ccc31df68ecc42ccf4149144866c47d8a # v3.0.2
with:
name: ${{ matrix.asset_name }}
- name: Set executable flag
run: chmod +x ${{ matrix.artifact_name }}
- name: Set zip name
run: echo "zip_name=capa-${GITHUB_REF#refs/tags/}-${{ matrix.asset_name }}.zip" >> $GITHUB_ENV
- name: Zip ${{ matrix.artifact_name }} into ${{ env.zip_name }}
run: zip ${{ env.zip_name }} ${{ matrix.artifact_name }}
- name: Upload ${{ env.zip_name }} to GH Release
uses: svenstaro/upload-release-action@2728235f7dc9ff598bd86ce3c274b74f802d2208 # v2
with:
repo_token: ${{ secrets.GITHUB_TOKEN}}
file: ${{ env.zip_name }}
tag: ${{ github.ref }}
name: build
on:
release:
types: [edited, published]
jobs:
build:
name: PyInstaller for ${{ matrix.os }}
runs-on: ${{ matrix.os }}
strategy:
matrix:
include:
- os: ubuntu-16.04
# use old linux so that the shared library versioning is more portable
artifact_name: capa
asset_name: linux
- os: windows-latest
artifact_name: capa.exe
asset_name: windows
- os: macos-latest
artifact_name: capa
asset_name: macos
steps:
- name: Checkout capa
uses: actions/checkout@v2
with:
submodules: true
- name: Set up Python 2.7
uses: actions/setup-python@v2
with:
python-version: 2.7
- if: matrix.os == 'ubuntu-latest'
run: sudo apt-get install -y libyaml-dev
- if: matrix.os == 'windows-latest'
run: |
choco install vcredist2008
choco install --ignore-dependencies vcpython27
- name: Install PyInstaller
# pyinstaller 4 doesn't support Python 2.7
run: pip install 'pyinstaller==3.*'
- name: Install capa
run: pip install -e .
- name: Build standalone executable
run: pyinstaller .github/pyinstaller/pyinstaller.spec
- name: Does it run?
run: dist/capa "tests/data/Practical Malware Analysis Lab 01-01.dll_"
- uses: actions/upload-artifact@v2
with:
name: ${{ matrix.asset_name }}
path: dist/${{ matrix.artifact_name }}
zip:
name: zip ${{ matrix.asset_name }}
runs-on: ubuntu-latest
needs: build
strategy:
matrix:
include:
- asset_name: linux
artifact_name: capa
- asset_name: windows
artifact_name: capa.exe
- asset_name: macos
artifact_name: capa
steps:
- name: Download ${{ matrix.asset_name }}
uses: actions/download-artifact@v2
with:
name: ${{ matrix.asset_name }}
- name: Set executable flag
run: chmod +x ${{ matrix.artifact_name }}
- name: Set zip name
run: echo "zip_name=capa-${GITHUB_REF#refs/tags/}-${{ matrix.asset_name }}.zip" >> $GITHUB_ENV
- name: Zip ${{ matrix.artifact_name }} into ${{ env.zip_name }}
run: zip ${{ env.zip_name }} ${{ matrix.artifact_name }}
- name: Upload ${{ env.zip_name }} to GH Release
uses: svenstaro/upload-release-action@v2
with:
repo_token: ${{ secrets.GITHUB_TOKEN}}
file: ${{ env.zip_name }}
tag: ${{ github.ref }}

View File

@@ -1,43 +0,0 @@
name: changelog
on:
# We need pull_request_target instead of pull_request because a write
# repository token is needed to add a review to a PR. DO NOT BUILD
# OR RUN UNTRUSTED CODE FROM PRs IN THIS ACTION
pull_request_target:
types: [opened, edited, synchronize]
permissions: read-all
jobs:
check_changelog:
# no need to check for dependency updates via dependabot
if: github.actor != 'dependabot[bot]' && github.actor != 'dependabot-preview[bot]'
runs-on: ubuntu-20.04
env:
NO_CHANGELOG: '[x] No CHANGELOG update needed'
steps:
- name: Get changed files
id: files
uses: Ana06/get-changed-files@e0c398b7065a8d84700c471b6afc4116d1ba4e96 # v2.2.0
- name: check changelog updated
id: changelog_updated
env:
PR_BODY: ${{ github.event.pull_request.body }}
FILES: ${{ steps.files.outputs.modified }}
run: |
echo $FILES | grep -qF 'CHANGELOG.md' || echo $PR_BODY | grep -qiF "$NO_CHANGELOG"
- name: Reject pull request if no CHANGELOG update
if: ${{ always() && steps.changelog_updated.outcome == 'failure' }}
uses: Ana06/automatic-pull-request-review@0cf4e8a17ba79344ed3fdd7fed6dd0311d08a9d4 # v0.1.0
with:
repo-token: ${{ secrets.GITHUB_TOKEN }}
event: REQUEST_CHANGES
body: "Please add bug fixes, new features, breaking changes and anything else you think is worthwhile mentioning to the `master (unreleased)` section of CHANGELOG.md. If no CHANGELOG update is needed add the following to the PR description: `${{ env.NO_CHANGELOG }}`"
allow_duplicate: false
- name: Dismiss previous review if CHANGELOG update
uses: Ana06/automatic-pull-request-review@0cf4e8a17ba79344ed3fdd7fed6dd0311d08a9d4 # v0.1.0
with:
repo-token: ${{ secrets.GITHUB_TOKEN }}
event: DISMISS
body: "CHANGELOG updated or no update needed, thanks! :smile:"

View File

@@ -1,21 +0,0 @@
name: PIP audit
on:
schedule:
- cron: '0 8 * * 1'
jobs:
test:
runs-on: ubuntu-latest
timeout-minutes: 20
strategy:
matrix:
python-version: ["3.11"]
steps:
- name: Check out repository code
uses: actions/checkout@v4
- uses: pypa/gh-action-pip-audit@v1.0.8
with:
inputs: .

View File

@@ -1,41 +1,29 @@
# use PyPI trusted publishing, as described here:
# https://blog.trailofbits.com/2023/05/23/trusted-publishing-a-new-benchmark-for-packaging-security/
name: publish to pypi
on:
release:
types: [published]
permissions:
contents: write
jobs:
pypi-publish:
runs-on: ubuntu-latest
environment:
name: release
permissions:
id-token: write
steps:
- uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
- name: Set up Python
uses: actions/setup-python@d27e3f3d7c64b4bbf8e4abfb9b63b83e846e0435 # v4.5.0
with:
python-version: '3.8'
- name: Install dependencies
run: |
python -m pip install --upgrade pip
pip install -e .[build]
- name: build package
run: |
python -m build
- name: upload package artifacts
uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
with:
path: dist/*
- name: publish package
uses: pypa/gh-action-pypi-publish@f5622bde02b04381239da3573277701ceca8f6a0 # release/v1
with:
skip-existing: true
verbose: true
print-hash: true
# This workflows will upload a Python Package using Twine when a release is created
# For more information see: https://help.github.com/en/actions/language-and-framework-guides/using-python-with-github-actions#publishing-to-package-registries
name: publish to pypi
on:
release:
types: [published]
jobs:
deploy:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Set up Python
uses: actions/setup-python@v2
with:
python-version: '2.7'
- name: Install dependencies
run: |
python -m pip install --upgrade pip
pip install setuptools wheel twine
- name: Build and publish
env:
TWINE_USERNAME: ${{ secrets.PYPI_USERNAME }}
TWINE_PASSWORD: ${{ secrets.PYPI_PASSWORD }}
run: |
python setup.py sdist bdist_wheel
twine upload --skip-existing dist/*

View File

@@ -1,72 +0,0 @@
# This workflow uses actions that are not certified by GitHub. They are provided
# by a third-party and are governed by separate terms of service, privacy
# policy, and support documentation.
name: Scorecard supply-chain security
on:
# For Branch-Protection check. Only the default branch is supported. See
# https://github.com/ossf/scorecard/blob/main/docs/checks.md#branch-protection
branch_protection_rule:
# To guarantee Maintained check is occasionally updated. See
# https://github.com/ossf/scorecard/blob/main/docs/checks.md#maintained
schedule:
- cron: '43 4 * * 3'
push:
branches: [ "master" ]
# Declare default permissions as read only.
permissions: read-all
jobs:
analysis:
name: Scorecard analysis
runs-on: ubuntu-latest
permissions:
# Needed to upload the results to code-scanning dashboard.
security-events: write
# Needed to publish results and get a badge (see publish_results below).
id-token: write
# Uncomment the permissions below if installing in a private repository.
# contents: read
# actions: read
steps:
- name: "Checkout code"
uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8 # v3.1.0
with:
persist-credentials: false
- name: "Run analysis"
uses: ossf/scorecard-action@99c53751e09b9529366343771cc321ec74e9bd3d # v2.0.6
with:
results_file: results.sarif
results_format: sarif
# (Optional) "write" PAT token. Uncomment the `repo_token` line below if:
# - you want to enable the Branch-Protection check on a *public* repository, or
# - you are installing Scorecard on a *private* repository
# To create the PAT, follow the steps in https://github.com/ossf/scorecard-action#authentication-with-pat.
# repo_token: ${{ secrets.SCORECARD_TOKEN }}
# Public repositories:
# - Publish results to OpenSSF REST API for easy access by consumers
# - Allows the repository to include the Scorecard badge.
# - See https://github.com/ossf/scorecard-action#publishing-results.
# For private repositories:
# - `publish_results` will always be set to `false`, regardless
# of the value entered here.
publish_results: true
# Upload the results as artifacts (optional). Commenting out will disable uploads of run results in SARIF
# format to the repository Actions tab.
- name: "Upload artifact"
uses: actions/upload-artifact@3cea5372237819ed00197afe530f5a7ea3e805c8 # v3.1.0
with:
name: SARIF file
path: results.sarif
retention-days: 5
# Upload the results to GitHub's code scanning dashboard.
- name: "Upload to code-scanning"
uses: github/codeql-action/upload-sarif@807578363a7869ca324a79039e6db9c843e0e100 # v2.1.27
with:
sarif_file: results.sarif

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@@ -1,32 +0,0 @@
name: tag
on:
release:
types: [published]
permissions: read-all
jobs:
tag:
name: Tag capa rules
runs-on: ubuntu-20.04
steps:
- name: Checkout capa-rules
uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
with:
repository: mandiant/capa-rules
token: ${{ secrets.CAPA_TOKEN }}
- name: Tag capa-rules
run: |
# user information is needed to create annotated tags (with a message)
git config user.email 'capa-dev@mandiant.com'
git config user.name 'Capa Bot'
name=${{ github.event.release.tag_name }}
git tag $name -m "https://github.com/mandiant/capa/releases/$name"
# TODO update branch name-major=${name%%.*}
- name: Push tag to capa-rules
uses: ad-m/github-push-action@0fafdd62b84042d49ec0cb92d9cac7f7ce4ec79e # master
with:
repository: mandiant/capa-rules
github_token: ${{ secrets.CAPA_TOKEN }}
tags: true

View File

@@ -6,199 +6,65 @@ on:
pull_request:
branches: [ master ]
permissions: read-all
# save workspaces to speed up testing
env:
CAPA_SAVE_WORKSPACE: "True"
jobs:
changelog_format:
runs-on: ubuntu-20.04
steps:
- name: Checkout capa
uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
# The sync GH action in capa-rules relies on a single '- *$' in the CHANGELOG file
- name: Ensure CHANGELOG has '- *$'
run: |
number=$(grep '\- *$' CHANGELOG.md | wc -l)
if [ $number != 1 ]; then exit 1; fi
code_style:
runs-on: ubuntu-20.04
runs-on: ubuntu-latest
steps:
- name: Checkout capa
uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
# use latest available python to take advantage of best performance
- name: Set up Python 3.11
uses: actions/setup-python@d27e3f3d7c64b4bbf8e4abfb9b63b83e846e0435 # v4.5.0
uses: actions/checkout@v2
- name: Set up Python 3.8
uses: actions/setup-python@v2
with:
python-version: "3.11"
python-version: 3.8
- name: Install dependencies
run: pip install -e .[dev]
- name: Lint with ruff
run: pre-commit run ruff
run: pip install 'isort==5.*' black
- name: Lint with isort
run: pre-commit run isort --show-diff-on-failure
run: isort --profile black --length-sort --line-width 120 -c .
- name: Lint with black
run: pre-commit run black --show-diff-on-failure
- name: Lint with flake8
run: pre-commit run flake8 --hook-stage manual
- name: Check types with mypy
run: pre-commit run mypy --hook-stage manual
run: black -l 120 --check .
rule_linter:
runs-on: ubuntu-20.04
runs-on: ubuntu-latest
steps:
- name: Checkout capa with submodules
uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
- name: Checkout capa with rules submodule
uses: actions/checkout@v2
with:
submodules: recursive
- name: Set up Python 3.11
uses: actions/setup-python@d27e3f3d7c64b4bbf8e4abfb9b63b83e846e0435 # v4.5.0
submodules: true
- name: Set up Python 3.8
uses: actions/setup-python@v2
with:
python-version: "3.11"
python-version: 3.8
# We don't need vivisect, so we can install capa using Python3
- name: Install capa
run: pip install -e .[dev]
run: pip install -e .
- name: Run rule linter
run: python scripts/lint.py rules/
tests:
name: Tests in ${{ matrix.python-version }} on ${{ matrix.os }}
runs-on: ${{ matrix.os }}
name: Tests in ${{ matrix.python }}
runs-on: ubuntu-latest
needs: [code_style, rule_linter]
strategy:
fail-fast: false
matrix:
os: [ubuntu-20.04, windows-2019, macos-11]
# across all operating systems
python-version: ["3.8", "3.11"]
include:
# on Ubuntu run these as well
- os: ubuntu-20.04
python-version: "3.8"
- os: ubuntu-20.04
python-version: "3.9"
- os: ubuntu-20.04
python-version: "3.10"
- python: 2.7
- python: 3.7
- python: 3.8
- python: 3.9.1
steps:
- name: Checkout capa with submodules
uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
with:
submodules: recursive
- name: Set up Python ${{ matrix.python-version }}
uses: actions/setup-python@d27e3f3d7c64b4bbf8e4abfb9b63b83e846e0435 # v4.5.0
with:
python-version: ${{ matrix.python-version }}
- name: Install pyyaml
if: matrix.os == 'ubuntu-20.04'
run: sudo apt-get install -y libyaml-dev
- name: Install capa
run: pip install -e .[dev]
- name: Run tests (fast)
# this set of tests runs about 80% of the cases in 20% of the time,
# and should catch most errors quickly.
run: pre-commit run pytest-fast --all-files --hook-stage manual
- name: Run tests
run: pytest -v tests/
binja-tests:
name: Binary Ninja tests for ${{ matrix.python-version }}
env:
BN_SERIAL: ${{ secrets.BN_SERIAL }}
runs-on: ubuntu-20.04
needs: [tests]
strategy:
fail-fast: false
matrix:
python-version: ["3.8", "3.11"]
steps:
- name: Checkout capa with submodules
# do only run if BN_SERIAL is available, have to do this in every step, see https://github.com/orgs/community/discussions/26726#discussioncomment-3253118
if: ${{ env.BN_SERIAL != 0 }}
uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
with:
submodules: recursive
- name: Set up Python ${{ matrix.python-version }}
if: ${{ env.BN_SERIAL != 0 }}
uses: actions/setup-python@d27e3f3d7c64b4bbf8e4abfb9b63b83e846e0435 # v4.5.0
with:
python-version: ${{ matrix.python-version }}
- name: Install pyyaml
if: ${{ env.BN_SERIAL != 0 }}
run: sudo apt-get install -y libyaml-dev
- name: Install capa
if: ${{ env.BN_SERIAL != 0 }}
run: pip install -e .[dev]
- name: install Binary Ninja
if: ${{ env.BN_SERIAL != 0 }}
run: |
mkdir ./.github/binja
curl "https://raw.githubusercontent.com/Vector35/binaryninja-api/6812c97/scripts/download_headless.py" -o ./.github/binja/download_headless.py
python ./.github/binja/download_headless.py --serial ${{ env.BN_SERIAL }} --output .github/binja/BinaryNinja-headless.zip
unzip .github/binja/BinaryNinja-headless.zip -d .github/binja/
python .github/binja/binaryninja/scripts/install_api.py --install-on-root --silent
- name: Run tests
if: ${{ env.BN_SERIAL != 0 }}
env:
BN_LICENSE: ${{ secrets.BN_LICENSE }}
run: pytest -v tests/test_binja_features.py # explicitly refer to the binja tests for performance. other tests run above.
ghidra-tests:
name: Ghidra tests for ${{ matrix.python-version }}
runs-on: ubuntu-20.04
needs: [tests]
strategy:
fail-fast: false
matrix:
python-version: ["3.8", "3.11"]
java-version: ["17"]
gradle-version: ["7.3"]
ghidra-version: ["10.3"]
public-version: ["PUBLIC_20230510"] # for ghidra releases
jep-version: ["4.1.1"]
ghidrathon-version: ["3.0.0"]
steps:
- name: Checkout capa with submodules
uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
uses: actions/checkout@v2
with:
submodules: true
- name: Set up Python ${{ matrix.python-version }}
uses: actions/setup-python@d27e3f3d7c64b4bbf8e4abfb9b63b83e846e0435 # v4.5.0
- name: Set up Python ${{ matrix.python }}
uses: actions/setup-python@v2
with:
python-version: ${{ matrix.python-version }}
- name: Set up Java ${{ matrix.java-version }}
uses: actions/setup-java@5ffc13f4174014e2d4d4572b3d74c3fa61aeb2c2 # v3
with:
distribution: 'temurin'
java-version: ${{ matrix.java-version }}
- name: Set up Gradle ${{ matrix.gradle-version }}
uses: gradle/gradle-build-action@40b6781dcdec2762ad36556682ac74e31030cfe2 # v2.5.1
with:
gradle-version: ${{ matrix.gradle-version }}
- name: Install Jep ${{ matrix.jep-version }}
run : pip install jep==${{ matrix.jep-version }}
- name: Install Ghidra ${{ matrix.ghidra-version }}
run: |
mkdir ./.github/ghidra
wget "https://github.com/NationalSecurityAgency/ghidra/releases/download/Ghidra_${{ matrix.ghidra-version }}_build/ghidra_${{ matrix.ghidra-version }}_${{ matrix.public-version }}.zip" -O ./.github/ghidra/ghidra_${{ matrix.ghidra-version }}_PUBLIC.zip
unzip .github/ghidra/ghidra_${{ matrix.ghidra-version }}_PUBLIC.zip -d .github/ghidra/
- name: Install Ghidrathon
run : |
mkdir ./.github/ghidrathon
curl -o ./.github/ghidrathon/ghidrathon-${{ matrix.ghidrathon-version }}.zip "https://codeload.github.com/mandiant/Ghidrathon/zip/refs/tags/v${{ matrix.ghidrathon-version }}"
unzip .github/ghidrathon/ghidrathon-${{ matrix.ghidrathon-version }}.zip -d .github/ghidrathon/
gradle -p ./.github/ghidrathon/Ghidrathon-${{ matrix.ghidrathon-version }}/ -PGHIDRA_INSTALL_DIR=$(pwd)/.github/ghidra/ghidra_${{ matrix.ghidra-version }}_PUBLIC
unzip .github/ghidrathon/Ghidrathon-${{ matrix.ghidrathon-version }}/dist/*.zip -d .github/ghidra/ghidra_${{ matrix.ghidra-version }}_PUBLIC/Ghidra/Extensions
python-version: ${{ matrix.python }}
- name: Install pyyaml
run: sudo apt-get install -y libyaml-dev
- name: Install capa
run: pip install -e .[dev]
run: pip install -e .[dev]
- name: Run tests
run: |
mkdir ./.github/ghidra/project
.github/ghidra/ghidra_${{ matrix.ghidra-version }}_PUBLIC/support/analyzeHeadless .github/ghidra/project ghidra_test -Import ./tests/data/mimikatz.exe_ -ScriptPath ./tests/ -PostScript test_ghidra_features.py > ../output.log
cat ../output.log
exit_code=$(cat ../output.log | grep exit | awk '{print $NF}')
exit $exit_code
run: pytest tests/

20
.gitignore vendored
View File

@@ -108,21 +108,9 @@ venv.bak/
*.viv
*.idb
*.i64
.vscode
!rules/lib
scripts/perf/*.txt
scripts/perf/*.svg
scripts/perf/*.zip
.direnv
.envrc
.DS_Store
*/.DS_Store
Pipfile
Pipfile.lock
/cache/
.github/binja/binaryninja
.github/binja/download_headless.py
.github/binja/BinaryNinja-headless.zip
# hooks/ci.sh output
isort-output.log
black-output.log
rule-linter-output.log

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@@ -1,129 +0,0 @@
# install the pre-commit hooks:
#
# pre-commit install --hook-type pre-commit
# pre-commit installed at .git/hooks/pre-commit
#
# pre-commit install --hook-type pre-push
# pre-commit installed at .git/hooks/pre-push
#
# run all linters liks:
#
# pre-commit run --all-files
# isort....................................................................Passed
# black....................................................................Passed
# ruff.....................................................................Passed
# flake8...................................................................Passed
# mypy.....................................................................Passed
#
# run a single linter like:
#
# pre-commit run --all-files isort
# isort....................................................................Passed
repos:
- repo: local
hooks:
- id: isort
name: isort
stages: [commit, push, manual]
language: system
entry: isort
args:
- "--length-sort"
- "--profile"
- "black"
- "--line-length=120"
- "--skip-glob"
- "*_pb2.py"
- "capa/"
- "scripts/"
- "tests/"
always_run: true
pass_filenames: false
- repo: local
hooks:
- id: black
name: black
stages: [commit, push, manual]
language: system
entry: black
args:
- "--line-length=120"
- "--extend-exclude"
- ".*_pb2.py"
- "capa/"
- "scripts/"
- "tests/"
always_run: true
pass_filenames: false
- repo: local
hooks:
- id: ruff
name: ruff
stages: [commit, push, manual]
language: system
entry: ruff
args:
- "check"
- "--config"
- ".github/ruff.toml"
- "capa/"
- "scripts/"
- "tests/"
always_run: true
pass_filenames: false
- repo: local
hooks:
- id: flake8
name: flake8
stages: [push, manual]
language: system
entry: flake8
args:
- "--config"
- ".github/flake8.ini"
- "--extend-exclude"
- "capa/render/proto/capa_pb2.py"
- "capa/"
- "scripts/"
- "tests/"
always_run: true
pass_filenames: false
- repo: local
hooks:
- id: mypy
name: mypy
stages: [push, manual]
language: system
entry: mypy
args:
- "--check-untyped-defs"
- "--ignore-missing-imports"
- "--config-file=.github/mypy/mypy.ini"
- "capa/"
- "scripts/"
- "tests/"
always_run: true
pass_filenames: false
- repo: local
hooks:
- id: pytest-fast
name: pytest (fast)
stages: [manual]
language: system
entry: pytest
args:
- "tests/"
- "--ignore=tests/test_binja_features.py"
- "--ignore=tests/test_ghidra_features.py"
- "--ignore=tests/test_ida_features.py"
- "--ignore=tests/test_viv_features.py"
- "--ignore=tests/test_main.py"
- "--ignore=tests/test_scripts.py"
always_run: true
pass_filenames: false

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@@ -187,7 +187,7 @@
same "printed page" as the copyright notice for easier
identification within third-party archives.
Copyright (C) 2023 Mandiant, Inc.
Copyright (C) 2020 FireEye, Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.

215
README.md
View File

@@ -1,22 +1,14 @@
![capa](https://github.com/mandiant/capa/blob/master/.github/logo.png)
![capa](.github/logo.png)
[![PyPI - Python Version](https://img.shields.io/pypi/pyversions/flare-capa)](https://pypi.org/project/flare-capa)
[![Last release](https://img.shields.io/github/v/release/mandiant/capa)](https://github.com/mandiant/capa/releases)
[![Number of rules](https://img.shields.io/badge/rules-866-blue.svg)](https://github.com/mandiant/capa-rules)
[![CI status](https://github.com/mandiant/capa/workflows/CI/badge.svg)](https://github.com/mandiant/capa/actions?query=workflow%3ACI+event%3Apush+branch%3Amaster)
[![Downloads](https://img.shields.io/github/downloads/mandiant/capa/total)](https://github.com/mandiant/capa/releases)
[![CI status](https://github.com/fireeye/capa/workflows/CI/badge.svg)](https://github.com/fireeye/capa/actions?query=workflow%3ACI+event%3Apush+branch%3Amaster)
[![Number of rules](https://img.shields.io/badge/rules-455-blue.svg)](https://github.com/fireeye/capa-rules)
[![License](https://img.shields.io/badge/license-Apache--2.0-green.svg)](LICENSE.txt)
capa detects capabilities in executable files.
You run it against a PE, ELF, .NET module, shellcode file, or a sandbox report and it tells you what it thinks the program can do.
You run it against a PE file or shellcode and it tells you what it thinks the program can do.
For example, it might suggest that the file is a backdoor, is capable of installing services, or relies on HTTP to communicate.
Check out our capa blog posts:
- [Dynamic capa: Exploring Executable Run-Time Behavior with the CAPE Sandbox](https://www.mandiant.com/resources/blog/dynamic-capa-executable-behavior-cape-sandbox)
- [capa v4: casting a wider .NET](https://www.mandiant.com/resources/blog/capa-v4-casting-wider-net) (.NET support)
- [ELFant in the Room capa v3](https://www.mandiant.com/resources/elfant-in-the-room-capa-v3) (ELF support)
- [capa 2.0: Better, Stronger, Faster](https://www.mandiant.com/resources/capa-2-better-stronger-faster)
- [capa: Automatically Identify Malware Capabilities](https://www.mandiant.com/resources/capa-automatically-identify-malware-capabilities)
Check out the overview in our first [capa blog post](https://www.fireeye.com/blog/threat-research/2020/07/capa-automatically-identify-malware-capabilities.html).
```
$ capa.exe suspicious.exe
@@ -68,11 +60,18 @@ $ capa.exe suspicious.exe
# download and usage
Download stable releases of the standalone capa binaries [here](https://github.com/mandiant/capa/releases). You can run the standalone binaries without installation. capa is a command line tool that should be run from the terminal.
Download stable releases of the standalone capa binaries [here](https://github.com/fireeye/capa/releases). You can run the standalone binaries without installation. capa is a command line tool that should be run from the terminal.
To use capa as a library or integrate with another tool, see [doc/installation.md](https://github.com/mandiant/capa/blob/master/doc/installation.md) for further setup instructions.
<!--
Alternatively, you can fetch a nightly build of a standalone binary from one of the following links. These are built using the latest development branch.
- Windows 64bit: TODO
- Linux: TODO
- OSX: TODO
-->
For more information about how to use capa, see [doc/usage.md](https://github.com/mandiant/capa/blob/master/doc/usage.md).
To use capa as a library or integrate with another tool, see [doc/installation.md](doc/installation.md) for further setup instructions.
For more information about how to use capa, see [doc/usage.md](doc/usage.md).
# example
@@ -89,133 +88,34 @@ This is useful for at least two reasons:
- it shows where within the binary an experienced analyst might study with IDA Pro
```
$ capa.exe suspicious.exe -vv
λ capa.exe suspicious.exe -vv
...
execute shell command and capture output
namespace c2/shell
author matthew.williams@mandiant.com
author matthew.williams@fireeye.com
scope function
att&ck Execution::Command and Scripting Interpreter::Windows Command Shell [T1059.003]
references https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfoa
function @ 0x4011C0
examples Practical Malware Analysis Lab 14-02.exe_:0x4011C0
function @ 0x10003A13
and:
match: create a process with modified I/O handles and window @ 0x4011C0
match: create a process with modified I/O handles and window @ 0x10003A13
and:
number: 257 = STARTF_USESTDHANDLES | STARTF_USESHOWWINDOW @ 0x4012B8
or:
number: 68 = StartupInfo.cb (size) @ 0x401282
or: = API functions that accept a pointer to a STARTUPINFO structure
api: kernel32.CreateProcess @ 0x401343
match: create pipe @ 0x4011C0
api: kernel32.CreateProcess @ 0x10003D6D
number: 0x101 @ 0x10003B03
or:
number: 0x44 @ 0x10003ADC
optional:
api: kernel32.GetStartupInfo @ 0x10003AE4
match: create pipe @ 0x10003A13
or:
api: kernel32.CreatePipe @ 0x40126F, 0x401280
optional:
match: create thread @ 0x40136A, 0x4013BA
or:
and:
os: windows
or:
api: kernel32.CreateThread @ 0x4013D7
or:
and:
os: windows
or:
api: kernel32.CreateThread @ 0x401395
api: kernel32.CreatePipe @ 0x10003ACB
or:
string: "cmd.exe" @ 0x4012FD
string: cmd.exe /c @ 0x10003AED
...
```
Additionally, capa also supports analyzing [CAPE](https://github.com/kevoreilly/CAPEv2) sandbox reports for dynamic capabilty extraction.
In order to use this, you first submit your sample to CAPE for analysis, and then run capa against the generated report (JSON).
Here's an example of running capa against a packed binary, and then running capa against the CAPE report of that binary:
```yaml
$ capa 05be49819139a3fdcdbddbdefd298398779521f3d68daa25275cc77508e42310.exe
WARNING:capa.capabilities.common:--------------------------------------------------------------------------------
WARNING:capa.capabilities.common: This sample appears to be packed.
WARNING:capa.capabilities.common:
WARNING:capa.capabilities.common: Packed samples have often been obfuscated to hide their logic.
WARNING:capa.capabilities.common: capa cannot handle obfuscation well using static analysis. This means the results may be misleading or incomplete.
WARNING:capa.capabilities.common: If possible, you should try to unpack this input file before analyzing it with capa.
WARNING:capa.capabilities.common: Alternatively, run the sample in a supported sandbox and invoke capa against the report to obtain dynamic analysis results.
WARNING:capa.capabilities.common:
WARNING:capa.capabilities.common: Identified via rule: (internal) packer file limitation
WARNING:capa.capabilities.common:
WARNING:capa.capabilities.common: Use -v or -vv if you really want to see the capabilities identified by capa.
WARNING:capa.capabilities.common:--------------------------------------------------------------------------------
$ capa 05be49819139a3fdcdbddbdefd298398779521f3d68daa25275cc77508e42310.json
┍━━━━━━━━━━━━━━━━━━━━━━━━┯━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┑
│ ATT&CK Tactic │ ATT&CK Technique │
┝━━━━━━━━━━━━━━━━━━━━━━━━┿━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┥
│ CREDENTIAL ACCESS │ Credentials from Password Stores T1555 │
├────────────────────────┼────────────────────────────────────────────────────────────────────────────────────┤
│ DEFENSE EVASION │ File and Directory Permissions Modification T1222 │
│ │ Modify Registry T1112 │
│ │ Obfuscated Files or Information T1027 │
│ │ Virtualization/Sandbox Evasion::User Activity Based Checks T1497.002 │
├────────────────────────┼────────────────────────────────────────────────────────────────────────────────────┤
│ DISCOVERY │ Account Discovery T1087 │
│ │ Application Window Discovery T1010 │
│ │ File and Directory Discovery T1083 │
│ │ Query Registry T1012 │
│ │ System Information Discovery T1082 │
│ │ System Location Discovery::System Language Discovery T1614.001 │
│ │ System Owner/User Discovery T1033 │
├────────────────────────┼────────────────────────────────────────────────────────────────────────────────────┤
│ EXECUTION │ System Services::Service Execution T1569.002 │
├────────────────────────┼────────────────────────────────────────────────────────────────────────────────────┤
│ PERSISTENCE │ Boot or Logon Autostart Execution::Registry Run Keys / Startup Folder T1547.001 │
│ │ Boot or Logon Autostart Execution::Winlogon Helper DLL T1547.004 │
│ │ Create or Modify System Process::Windows Service T1543.003 │
┕━━━━━━━━━━━━━━━━━━━━━━━━┷━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┙
┍━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┯━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┑
│ Capability │ Namespace │
┝━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┿━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┥
│ check for unmoving mouse cursor (3 matches) │ anti-analysis/anti-vm/vm-detection │
│ gather bitkinex information │ collection/file-managers │
│ gather classicftp information │ collection/file-managers │
│ gather filezilla information │ collection/file-managers │
│ gather total-commander information │ collection/file-managers │
│ gather ultrafxp information │ collection/file-managers │
│ resolve DNS (23 matches) │ communication/dns │
│ initialize Winsock library (7 matches) │ communication/socket │
│ act as TCP client (3 matches) │ communication/tcp/client │
│ create new key via CryptAcquireContext │ data-manipulation/encryption │
│ encrypt or decrypt via WinCrypt │ data-manipulation/encryption │
│ hash data via WinCrypt │ data-manipulation/hashing │
│ initialize hashing via WinCrypt │ data-manipulation/hashing │
│ hash data with MD5 │ data-manipulation/hashing/md5 │
│ generate random numbers via WinAPI │ data-manipulation/prng │
│ extract resource via kernel32 functions (2 matches) │ executable/resource │
│ interact with driver via control codes (2 matches) │ host-interaction/driver │
│ get Program Files directory (18 matches) │ host-interaction/file-system │
│ get common file path (575 matches) │ host-interaction/file-system │
│ create directory (2 matches) │ host-interaction/file-system/create │
│ delete file │ host-interaction/file-system/delete │
│ get file attributes (122 matches) │ host-interaction/file-system/meta │
│ set file attributes (8 matches) │ host-interaction/file-system/meta │
│ move file │ host-interaction/file-system/move │
│ find taskbar (3 matches) │ host-interaction/gui/taskbar/find │
│ get keyboard layout (12 matches) │ host-interaction/hardware/keyboard │
│ get disk size │ host-interaction/hardware/storage │
│ get hostname (4 matches) │ host-interaction/os/hostname │
│ allocate or change RWX memory (3 matches) │ host-interaction/process/inject │
│ query or enumerate registry key (3 matches) │ host-interaction/registry │
│ query or enumerate registry value (8 matches) │ host-interaction/registry │
│ delete registry key │ host-interaction/registry/delete │
│ start service │ host-interaction/service/start │
│ get session user name │ host-interaction/session │
│ persist via Run registry key │ persistence/registry/run │
│ persist via Winlogon Helper DLL registry key │ persistence/registry/winlogon-helper │
│ persist via Windows service (2 matches) │ persistence/service │
┕━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┷━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┙
```
capa uses a collection of rules to identify capabilities within a program.
These rules are easy to write, even for those new to reverse engineering.
By authoring rules, you can extend the capabilities that capa recognizes.
@@ -226,52 +126,39 @@ Here's an example rule used by capa:
```yaml
rule:
meta:
name: create TCP socket
namespace: communication/socket/tcp
authors:
- william.ballenthin@mandiant.com
- joakim@intezer.com
- anushka.virgaonkar@mandiant.com
scopes:
static: basic block
dynamic: call
mbc:
- Communication::Socket Communication::Create TCP Socket [C0001.011]
name: hash data with CRC32
namespace: data-manipulation/checksum/crc32
author: moritz.raabe@fireeye.com
scope: function
examples:
- Practical Malware Analysis Lab 01-01.dll_:0x10001010
- 2D3EDC218A90F03089CC01715A9F047F:0x403CBD
- 7D28CB106CB54876B2A5C111724A07CD:0x402350 # RtlComputeCrc32
features:
- or:
- and:
- number: 6 = IPPROTO_TCP
- number: 1 = SOCK_STREAM
- number: 2 = AF_INET
- or:
- api: ws2_32.socket
- api: ws2_32.WSASocket
- api: socket
- property/read: System.Net.Sockets.TcpClient::Client
- mnemonic: shr
- number: 0xEDB88320
- number: 8
- characteristic: nzxor
- api: RtlComputeCrc32
```
The [github.com/mandiant/capa-rules](https://github.com/mandiant/capa-rules) repository contains hundreds of standard library rules that are distributed with capa.
The [github.com/fireeye/capa-rules](https://github.com/fireeye/capa-rules) repository contains hundreds of standard library rules that are distributed with capa.
Please learn to write rules and contribute new entries as you find interesting techniques in malware.
If you use IDA Pro, then you can use the [capa explorer](https://github.com/mandiant/capa/tree/master/capa/ida/plugin) plugin.
capa explorer helps you identify interesting areas of a program and build new capa rules using features extracted directly from your IDA Pro database.
If you use IDA Pro, then you use can use the [capa explorer IDA plugin](capa/ida/plugin/).
capa explorer lets you quickly identify and navigate to interesting areas of a program and dissect capa rule matches at
the assembly level.
![capa + IDA Pro integration](https://github.com/mandiant/capa/blob/master/doc/img/explorer_expanded.png)
If you use Ghidra, you can use the Python 3 [Ghidra feature extractor](/capa/ghidra/). This integration enables capa to extract features directly from your Ghidra database, which can help you identify capabilities in programs that you analyze using Ghidra.
![capa + IDA Pro integration](doc/img/ida_plugin_intro.gif)
# further information
## capa
- [Installation](https://github.com/mandiant/capa/blob/master/doc/installation.md)
- [Usage](https://github.com/mandiant/capa/blob/master/doc/usage.md)
- [Limitations](https://github.com/mandiant/capa/blob/master/doc/limitations.md)
- [Contributing Guide](https://github.com/mandiant/capa/blob/master/.github/CONTRIBUTING.md)
- [doc/installation](doc/installation.md)
- [doc/usage](doc/usage.md)
- [doc/limitations](doc/limitations.md)
- [Contributing Guide](.github/CONTRIBUTING.md)
## capa rules
- [capa-rules repository](https://github.com/mandiant/capa-rules)
- [capa-rules rule format](https://github.com/mandiant/capa-rules/blob/master/doc/format.md)
## capa testfiles
The [capa-testfiles repository](https://github.com/mandiant/capa-testfiles) contains the data we use to test capa's code and rules
- [capa-rules repository](https://github.com/fireeye/capa-rules)
- [capa-rules rule format](https://github.com/fireeye/capa-rules/blob/master/doc/format.md)

View File

@@ -1,79 +0,0 @@
# -*- coding: utf-8 -*-
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
import itertools
import collections
from typing import Any, Tuple
from capa.rules import Scope, RuleSet
from capa.engine import FeatureSet, MatchResults
from capa.features.address import NO_ADDRESS
from capa.features.extractors.base_extractor import FeatureExtractor, StaticFeatureExtractor, DynamicFeatureExtractor
logger = logging.getLogger(__name__)
def find_file_capabilities(ruleset: RuleSet, extractor: FeatureExtractor, function_features: FeatureSet):
file_features: FeatureSet = collections.defaultdict(set)
for feature, va in itertools.chain(extractor.extract_file_features(), extractor.extract_global_features()):
# not all file features may have virtual addresses.
# if not, then at least ensure the feature shows up in the index.
# the set of addresses will still be empty.
if va:
file_features[feature].add(va)
else:
if feature not in file_features:
file_features[feature] = set()
logger.debug("analyzed file and extracted %d features", len(file_features))
file_features.update(function_features)
_, matches = ruleset.match(Scope.FILE, file_features, NO_ADDRESS)
return matches, len(file_features)
def has_file_limitation(rules: RuleSet, capabilities: MatchResults, is_standalone=True) -> bool:
file_limitation_rules = list(filter(lambda r: r.is_file_limitation_rule(), rules.rules.values()))
for file_limitation_rule in file_limitation_rules:
if file_limitation_rule.name not in capabilities:
continue
logger.warning("-" * 80)
for line in file_limitation_rule.meta.get("description", "").split("\n"):
logger.warning(" %s", line)
logger.warning(" Identified via rule: %s", file_limitation_rule.name)
if is_standalone:
logger.warning(" ")
logger.warning(" Use -v or -vv if you really want to see the capabilities identified by capa.")
logger.warning("-" * 80)
# bail on first file limitation
return True
return False
def find_capabilities(
ruleset: RuleSet, extractor: FeatureExtractor, disable_progress=None, **kwargs
) -> Tuple[MatchResults, Any]:
from capa.capabilities.static import find_static_capabilities
from capa.capabilities.dynamic import find_dynamic_capabilities
if isinstance(extractor, StaticFeatureExtractor):
# for the time being, extractors are either static or dynamic.
# Remove this assertion once that has changed
assert not isinstance(extractor, DynamicFeatureExtractor)
return find_static_capabilities(ruleset, extractor, disable_progress=disable_progress, **kwargs)
if isinstance(extractor, DynamicFeatureExtractor):
return find_dynamic_capabilities(ruleset, extractor, disable_progress=disable_progress, **kwargs)
raise ValueError(f"unexpected extractor type: {extractor.__class__.__name__}")

View File

@@ -1,198 +0,0 @@
# -*- coding: utf-8 -*-
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
import itertools
import collections
from typing import Any, Tuple
import tqdm
import capa.perf
import capa.features.freeze as frz
import capa.render.result_document as rdoc
from capa.rules import Scope, RuleSet
from capa.engine import FeatureSet, MatchResults
from capa.helpers import redirecting_print_to_tqdm
from capa.capabilities.common import find_file_capabilities
from capa.features.extractors.base_extractor import CallHandle, ThreadHandle, ProcessHandle, DynamicFeatureExtractor
logger = logging.getLogger(__name__)
def find_call_capabilities(
ruleset: RuleSet, extractor: DynamicFeatureExtractor, ph: ProcessHandle, th: ThreadHandle, ch: CallHandle
) -> Tuple[FeatureSet, MatchResults]:
"""
find matches for the given rules for the given call.
returns: tuple containing (features for call, match results for call)
"""
# all features found for the call.
features: FeatureSet = collections.defaultdict(set)
for feature, addr in itertools.chain(
extractor.extract_call_features(ph, th, ch), extractor.extract_global_features()
):
features[feature].add(addr)
# matches found at this thread.
_, matches = ruleset.match(Scope.CALL, features, ch.address)
for rule_name, res in matches.items():
rule = ruleset[rule_name]
for addr, _ in res:
capa.engine.index_rule_matches(features, rule, [addr])
return features, matches
def find_thread_capabilities(
ruleset: RuleSet, extractor: DynamicFeatureExtractor, ph: ProcessHandle, th: ThreadHandle
) -> Tuple[FeatureSet, MatchResults, MatchResults]:
"""
find matches for the given rules within the given thread.
returns: tuple containing (features for thread, match results for thread, match results for calls)
"""
# all features found within this thread,
# includes features found within calls.
features: FeatureSet = collections.defaultdict(set)
# matches found at the call scope.
# might be found at different calls, thats ok.
call_matches: MatchResults = collections.defaultdict(list)
for ch in extractor.get_calls(ph, th):
ifeatures, imatches = find_call_capabilities(ruleset, extractor, ph, th, ch)
for feature, vas in ifeatures.items():
features[feature].update(vas)
for rule_name, res in imatches.items():
call_matches[rule_name].extend(res)
for feature, va in itertools.chain(extractor.extract_thread_features(ph, th), extractor.extract_global_features()):
features[feature].add(va)
# matches found within this thread.
_, matches = ruleset.match(Scope.THREAD, features, th.address)
for rule_name, res in matches.items():
rule = ruleset[rule_name]
for va, _ in res:
capa.engine.index_rule_matches(features, rule, [va])
return features, matches, call_matches
def find_process_capabilities(
ruleset: RuleSet, extractor: DynamicFeatureExtractor, ph: ProcessHandle
) -> Tuple[MatchResults, MatchResults, MatchResults, int]:
"""
find matches for the given rules within the given process.
returns: tuple containing (match results for process, match results for threads, match results for calls, number of features)
"""
# all features found within this process,
# includes features found within threads (and calls).
process_features: FeatureSet = collections.defaultdict(set)
# matches found at the basic threads.
# might be found at different threads, thats ok.
thread_matches: MatchResults = collections.defaultdict(list)
# matches found at the call scope.
# might be found at different calls, thats ok.
call_matches: MatchResults = collections.defaultdict(list)
for th in extractor.get_threads(ph):
features, tmatches, cmatches = find_thread_capabilities(ruleset, extractor, ph, th)
for feature, vas in features.items():
process_features[feature].update(vas)
for rule_name, res in tmatches.items():
thread_matches[rule_name].extend(res)
for rule_name, res in cmatches.items():
call_matches[rule_name].extend(res)
for feature, va in itertools.chain(extractor.extract_process_features(ph), extractor.extract_global_features()):
process_features[feature].add(va)
_, process_matches = ruleset.match(Scope.PROCESS, process_features, ph.address)
return process_matches, thread_matches, call_matches, len(process_features)
def find_dynamic_capabilities(
ruleset: RuleSet, extractor: DynamicFeatureExtractor, disable_progress=None
) -> Tuple[MatchResults, Any]:
all_process_matches: MatchResults = collections.defaultdict(list)
all_thread_matches: MatchResults = collections.defaultdict(list)
all_call_matches: MatchResults = collections.defaultdict(list)
feature_counts = rdoc.DynamicFeatureCounts(file=0, processes=())
assert isinstance(extractor, DynamicFeatureExtractor)
with redirecting_print_to_tqdm(disable_progress):
with tqdm.contrib.logging.logging_redirect_tqdm():
pbar = tqdm.tqdm
if disable_progress:
# do not use tqdm to avoid unnecessary side effects when caller intends
# to disable progress completely
def pbar(s, *args, **kwargs):
return s
processes = list(extractor.get_processes())
pb = pbar(processes, desc="matching", unit=" processes", leave=False)
for p in pb:
process_matches, thread_matches, call_matches, feature_count = find_process_capabilities(
ruleset, extractor, p
)
feature_counts.processes += (
rdoc.ProcessFeatureCount(address=frz.Address.from_capa(p.address), count=feature_count),
)
logger.debug("analyzed %s and extracted %d features", p.address, feature_count)
for rule_name, res in process_matches.items():
all_process_matches[rule_name].extend(res)
for rule_name, res in thread_matches.items():
all_thread_matches[rule_name].extend(res)
for rule_name, res in call_matches.items():
all_call_matches[rule_name].extend(res)
# collection of features that captures the rule matches within process and thread scopes.
# mapping from feature (matched rule) to set of addresses at which it matched.
process_and_lower_features: FeatureSet = collections.defaultdict(set)
for rule_name, results in itertools.chain(
all_process_matches.items(), all_thread_matches.items(), all_call_matches.items()
):
locations = {p[0] for p in results}
rule = ruleset[rule_name]
capa.engine.index_rule_matches(process_and_lower_features, rule, locations)
all_file_matches, feature_count = find_file_capabilities(ruleset, extractor, process_and_lower_features)
feature_counts.file = feature_count
matches = dict(
itertools.chain(
# each rule exists in exactly one scope,
# so there won't be any overlap among these following MatchResults,
# and we can merge the dictionaries naively.
all_thread_matches.items(),
all_process_matches.items(),
all_call_matches.items(),
all_file_matches.items(),
)
)
meta = {
"feature_counts": feature_counts,
}
return matches, meta

View File

@@ -1,233 +0,0 @@
# -*- coding: utf-8 -*-
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import time
import logging
import itertools
import collections
from typing import Any, Tuple
import tqdm.contrib.logging
import capa.perf
import capa.features.freeze as frz
import capa.render.result_document as rdoc
from capa.rules import Scope, RuleSet
from capa.engine import FeatureSet, MatchResults
from capa.helpers import redirecting_print_to_tqdm
from capa.capabilities.common import find_file_capabilities
from capa.features.extractors.base_extractor import BBHandle, InsnHandle, FunctionHandle, StaticFeatureExtractor
logger = logging.getLogger(__name__)
def find_instruction_capabilities(
ruleset: RuleSet, extractor: StaticFeatureExtractor, f: FunctionHandle, bb: BBHandle, insn: InsnHandle
) -> Tuple[FeatureSet, MatchResults]:
"""
find matches for the given rules for the given instruction.
returns: tuple containing (features for instruction, match results for instruction)
"""
# all features found for the instruction.
features: FeatureSet = collections.defaultdict(set)
for feature, addr in itertools.chain(
extractor.extract_insn_features(f, bb, insn), extractor.extract_global_features()
):
features[feature].add(addr)
# matches found at this instruction.
_, matches = ruleset.match(Scope.INSTRUCTION, features, insn.address)
for rule_name, res in matches.items():
rule = ruleset[rule_name]
for addr, _ in res:
capa.engine.index_rule_matches(features, rule, [addr])
return features, matches
def find_basic_block_capabilities(
ruleset: RuleSet, extractor: StaticFeatureExtractor, f: FunctionHandle, bb: BBHandle
) -> Tuple[FeatureSet, MatchResults, MatchResults]:
"""
find matches for the given rules within the given basic block.
returns: tuple containing (features for basic block, match results for basic block, match results for instructions)
"""
# all features found within this basic block,
# includes features found within instructions.
features: FeatureSet = collections.defaultdict(set)
# matches found at the instruction scope.
# might be found at different instructions, thats ok.
insn_matches: MatchResults = collections.defaultdict(list)
for insn in extractor.get_instructions(f, bb):
ifeatures, imatches = find_instruction_capabilities(ruleset, extractor, f, bb, insn)
for feature, vas in ifeatures.items():
features[feature].update(vas)
for rule_name, res in imatches.items():
insn_matches[rule_name].extend(res)
for feature, va in itertools.chain(
extractor.extract_basic_block_features(f, bb), extractor.extract_global_features()
):
features[feature].add(va)
# matches found within this basic block.
_, matches = ruleset.match(Scope.BASIC_BLOCK, features, bb.address)
for rule_name, res in matches.items():
rule = ruleset[rule_name]
for va, _ in res:
capa.engine.index_rule_matches(features, rule, [va])
return features, matches, insn_matches
def find_code_capabilities(
ruleset: RuleSet, extractor: StaticFeatureExtractor, fh: FunctionHandle
) -> Tuple[MatchResults, MatchResults, MatchResults, int]:
"""
find matches for the given rules within the given function.
returns: tuple containing (match results for function, match results for basic blocks, match results for instructions, number of features)
"""
# all features found within this function,
# includes features found within basic blocks (and instructions).
function_features: FeatureSet = collections.defaultdict(set)
# matches found at the basic block scope.
# might be found at different basic blocks, thats ok.
bb_matches: MatchResults = collections.defaultdict(list)
# matches found at the instruction scope.
# might be found at different instructions, thats ok.
insn_matches: MatchResults = collections.defaultdict(list)
for bb in extractor.get_basic_blocks(fh):
features, bmatches, imatches = find_basic_block_capabilities(ruleset, extractor, fh, bb)
for feature, vas in features.items():
function_features[feature].update(vas)
for rule_name, res in bmatches.items():
bb_matches[rule_name].extend(res)
for rule_name, res in imatches.items():
insn_matches[rule_name].extend(res)
for feature, va in itertools.chain(extractor.extract_function_features(fh), extractor.extract_global_features()):
function_features[feature].add(va)
_, function_matches = ruleset.match(Scope.FUNCTION, function_features, fh.address)
return function_matches, bb_matches, insn_matches, len(function_features)
def find_static_capabilities(
ruleset: RuleSet, extractor: StaticFeatureExtractor, disable_progress=None
) -> Tuple[MatchResults, Any]:
all_function_matches: MatchResults = collections.defaultdict(list)
all_bb_matches: MatchResults = collections.defaultdict(list)
all_insn_matches: MatchResults = collections.defaultdict(list)
feature_counts = rdoc.StaticFeatureCounts(file=0, functions=())
library_functions: Tuple[rdoc.LibraryFunction, ...] = ()
assert isinstance(extractor, StaticFeatureExtractor)
with redirecting_print_to_tqdm(disable_progress):
with tqdm.contrib.logging.logging_redirect_tqdm():
pbar = tqdm.tqdm
if capa.helpers.is_runtime_ghidra():
# Ghidrathon interpreter cannot properly handle
# the TMonitor thread that is created via a monitor_interval
# > 0
pbar.monitor_interval = 0
if disable_progress:
# do not use tqdm to avoid unnecessary side effects when caller intends
# to disable progress completely
def pbar(s, *args, **kwargs):
return s
functions = list(extractor.get_functions())
n_funcs = len(functions)
pb = pbar(functions, desc="matching", unit=" functions", postfix="skipped 0 library functions", leave=False)
for f in pb:
t0 = time.time()
if extractor.is_library_function(f.address):
function_name = extractor.get_function_name(f.address)
logger.debug("skipping library function 0x%x (%s)", f.address, function_name)
library_functions += (
rdoc.LibraryFunction(address=frz.Address.from_capa(f.address), name=function_name),
)
n_libs = len(library_functions)
percentage = round(100 * (n_libs / n_funcs))
if isinstance(pb, tqdm.tqdm):
pb.set_postfix_str(f"skipped {n_libs} library functions ({percentage}%)")
continue
function_matches, bb_matches, insn_matches, feature_count = find_code_capabilities(
ruleset, extractor, f
)
feature_counts.functions += (
rdoc.FunctionFeatureCount(address=frz.Address.from_capa(f.address), count=feature_count),
)
t1 = time.time()
match_count = sum(len(res) for res in function_matches.values())
match_count += sum(len(res) for res in bb_matches.values())
match_count += sum(len(res) for res in insn_matches.values())
logger.debug(
"analyzed function 0x%x and extracted %d features, %d matches in %0.02fs",
f.address,
feature_count,
match_count,
t1 - t0,
)
for rule_name, res in function_matches.items():
all_function_matches[rule_name].extend(res)
for rule_name, res in bb_matches.items():
all_bb_matches[rule_name].extend(res)
for rule_name, res in insn_matches.items():
all_insn_matches[rule_name].extend(res)
# collection of features that captures the rule matches within function, BB, and instruction scopes.
# mapping from feature (matched rule) to set of addresses at which it matched.
function_and_lower_features: FeatureSet = collections.defaultdict(set)
for rule_name, results in itertools.chain(
all_function_matches.items(), all_bb_matches.items(), all_insn_matches.items()
):
locations = {p[0] for p in results}
rule = ruleset[rule_name]
capa.engine.index_rule_matches(function_and_lower_features, rule, locations)
all_file_matches, feature_count = find_file_capabilities(ruleset, extractor, function_and_lower_features)
feature_counts.file = feature_count
matches = dict(
itertools.chain(
# each rule exists in exactly one scope,
# so there won't be any overlap among these following MatchResults,
# and we can merge the dictionaries naively.
all_insn_matches.items(),
all_bb_matches.items(),
all_function_matches.items(),
all_file_matches.items(),
)
)
meta = {
"feature_counts": feature_counts,
"library_functions": library_functions,
}
return matches, meta

View File

@@ -1,4 +1,4 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
@@ -8,29 +8,11 @@
import copy
import collections
from typing import TYPE_CHECKING, Set, Dict, List, Tuple, Union, Mapping, Iterable, Iterator
import capa.perf
import capa.features.common
from capa.features.common import Result, Feature
from capa.features.address import Address
if TYPE_CHECKING:
# circular import, otherwise
import capa.rules
import capa.features
# a collection of features and the locations at which they are found.
#
# used throughout matching as the context in which features are searched:
# to check if a feature exists, do: `Number(0x10) in features`.
# to collect the locations of a feature, do: `features[Number(0x10)]`
#
# aliased here so that the type can be documented and xref'd.
FeatureSet = Dict[Feature, Set[Address]]
class Statement:
class Statement(object):
"""
superclass for structural nodes, such as and/or/not.
this exists to provide a default impl for `__str__` and `__repr__`,
@@ -38,194 +20,157 @@ class Statement:
"""
def __init__(self, description=None):
super().__init__()
super(Statement, self).__init__()
self.name = self.__class__.__name__
self.description = description
def __str__(self):
name = self.name.lower()
children = ",".join(map(str, self.get_children()))
if self.description:
return f"{name}({children} = {self.description})"
return "%s(%s = %s)" % (self.name.lower(), ",".join(map(str, self.get_children())), self.description)
else:
return f"{name}({children})"
return "%s(%s)" % (self.name.lower(), ",".join(map(str, self.get_children())))
def __repr__(self):
return str(self)
def evaluate(self, features: FeatureSet, short_circuit=True) -> Result:
def evaluate(self, ctx):
"""
classes that inherit `Statement` must implement `evaluate`
args:
short_circuit (bool): if true, then statements like and/or/some may short circuit.
ctx (defaultdict[Feature, set[VA]])
returns:
Result
"""
raise NotImplementedError()
def get_children(self) -> Iterator[Union["Statement", Feature]]:
def get_children(self):
if hasattr(self, "child"):
# this really confuses mypy because the property may not exist
# since its defined in the subclasses.
child = self.child # type: ignore
assert isinstance(child, (Statement, Feature))
yield child
yield self.child
if hasattr(self, "children"):
for child in self.children:
assert isinstance(child, (Statement, Feature))
yield child
def replace_child(self, existing, new):
if hasattr(self, "child"):
# this really confuses mypy because the property may not exist
# since its defined in the subclasses.
if self.child is existing: # type: ignore
if self.child is existing:
self.child = new
if hasattr(self, "children"):
children = self.children
for i, child in enumerate(children):
for i, child in enumerate(self.children):
if child is existing:
children[i] = new
self.children[i] = new
class Result(object):
"""
represents the results of an evaluation of statements against features.
instances of this class should behave like a bool,
e.g. `assert Result(True, ...) == True`
instances track additional metadata about evaluation results.
they contain references to the statement node (e.g. an And statement),
as well as the children Result instances.
we need this so that we can render the tree of expressions and their results.
"""
def __init__(self, success, statement, children, locations=None):
"""
args:
success (bool)
statement (capa.engine.Statement or capa.features.Feature)
children (list[Result])
locations (iterable[VA])
"""
super(Result, self).__init__()
self.success = success
self.statement = statement
self.children = children
self.locations = locations if locations is not None else ()
def __eq__(self, other):
if isinstance(other, bool):
return self.success == other
return False
def __bool__(self):
return self.success
def __nonzero__(self):
return self.success
class And(Statement):
"""
match if all of the children evaluate to True.
the order of evaluation is dictated by the property
`And.children` (type: List[Statement|Feature]).
a query optimizer may safely manipulate the order of these children.
"""
"""match if all of the children evaluate to True."""
def __init__(self, children, description=None):
super().__init__(description=description)
super(And, self).__init__(description=description)
self.children = children
def evaluate(self, ctx, short_circuit=True):
capa.perf.counters["evaluate.feature"] += 1
capa.perf.counters["evaluate.feature.and"] += 1
if short_circuit:
results = []
for child in self.children:
result = child.evaluate(ctx, short_circuit=short_circuit)
results.append(result)
if not result:
# short circuit
return Result(False, self, results)
return Result(True, self, results)
else:
results = [child.evaluate(ctx, short_circuit=short_circuit) for child in self.children]
success = all(results)
return Result(success, self, results)
def evaluate(self, ctx):
results = [child.evaluate(ctx) for child in self.children]
success = all(results)
return Result(success, self, results)
class Or(Statement):
"""
match if any of the children evaluate to True.
the order of evaluation is dictated by the property
`Or.children` (type: List[Statement|Feature]).
a query optimizer may safely manipulate the order of these children.
"""
"""match if any of the children evaluate to True."""
def __init__(self, children, description=None):
super().__init__(description=description)
super(Or, self).__init__(description=description)
self.children = children
def evaluate(self, ctx, short_circuit=True):
capa.perf.counters["evaluate.feature"] += 1
capa.perf.counters["evaluate.feature.or"] += 1
if short_circuit:
results = []
for child in self.children:
result = child.evaluate(ctx, short_circuit=short_circuit)
results.append(result)
if result:
# short circuit as soon as we hit one match
return Result(True, self, results)
return Result(False, self, results)
else:
results = [child.evaluate(ctx, short_circuit=short_circuit) for child in self.children]
success = any(results)
return Result(success, self, results)
def evaluate(self, ctx):
results = [child.evaluate(ctx) for child in self.children]
success = any(results)
return Result(success, self, results)
class Not(Statement):
"""match only if the child evaluates to False."""
def __init__(self, child, description=None):
super().__init__(description=description)
super(Not, self).__init__(description=description)
self.child = child
def evaluate(self, ctx, short_circuit=True):
capa.perf.counters["evaluate.feature"] += 1
capa.perf.counters["evaluate.feature.not"] += 1
results = [self.child.evaluate(ctx, short_circuit=short_circuit)]
def evaluate(self, ctx):
results = [self.child.evaluate(ctx)]
success = not results[0]
return Result(success, self, results)
class Some(Statement):
"""
match if at least N of the children evaluate to True.
the order of evaluation is dictated by the property
`Some.children` (type: List[Statement|Feature]).
a query optimizer may safely manipulate the order of these children.
"""
"""match if at least N of the children evaluate to True."""
def __init__(self, count, children, description=None):
super().__init__(description=description)
super(Some, self).__init__(description=description)
self.count = count
self.children = children
def evaluate(self, ctx, short_circuit=True):
capa.perf.counters["evaluate.feature"] += 1
capa.perf.counters["evaluate.feature.some"] += 1
if short_circuit:
results = []
satisfied_children_count = 0
for child in self.children:
result = child.evaluate(ctx, short_circuit=short_circuit)
results.append(result)
if result:
satisfied_children_count += 1
if satisfied_children_count >= self.count:
# short circuit as soon as we hit the threshold
return Result(True, self, results)
return Result(False, self, results)
else:
results = [child.evaluate(ctx, short_circuit=short_circuit) for child in self.children]
# note that here we cast the child result as a bool
# because we've overridden `__bool__` above.
#
# we can't use `if child is True` because the instance is not True.
success = sum([1 for child in results if bool(child) is True]) >= self.count
return Result(success, self, results)
def evaluate(self, ctx):
results = [child.evaluate(ctx) for child in self.children]
# note that here we cast the child result as a bool
# because we've overridden `__bool__` above.
#
# we can't use `if child is True` because the instance is not True.
success = sum([1 for child in results if bool(child) is True]) >= self.count
return Result(success, self, results)
class Range(Statement):
"""match if the child is contained in the ctx set with a count in the given range."""
def __init__(self, child, min=None, max=None, description=None):
super().__init__(description=description)
super(Range, self).__init__(description=description)
self.child = child
self.min = min if min is not None else 0
self.max = max if max is not None else (1 << 64 - 1)
def evaluate(self, ctx, **kwargs):
capa.perf.counters["evaluate.feature"] += 1
capa.perf.counters["evaluate.feature.range"] += 1
def evaluate(self, ctx):
count = len(ctx.get(self.child, []))
if self.min == 0 and count == 0:
return Result(True, self, [])
@@ -234,9 +179,9 @@ class Range(Statement):
def __str__(self):
if self.max == (1 << 64 - 1):
return f"range({str(self.child)}, min={self.min}, max=infinity)"
return "range(%s, min=%d, max=infinity)" % (str(self.child), self.min)
else:
return f"range({str(self.child)}, min={self.min}, max={self.max})"
return "range(%s, min=%d, max=%d)" % (str(self.child), self.min, self.max)
class Subscope(Statement):
@@ -245,66 +190,59 @@ class Subscope(Statement):
the engine should preprocess rules to extract subscope statements into their own rules.
"""
def __init__(self, scope, child, description=None):
super().__init__(description=description)
def __init__(self, scope, child):
super(Subscope, self).__init__()
self.scope = scope
self.child = child
def evaluate(self, ctx, **kwargs):
def evaluate(self, ctx):
raise ValueError("cannot evaluate a subscope directly!")
# mapping from rule name to list of: (location of match, result object)
#
# used throughout matching and rendering to collection the results
# of statement evaluation and their locations.
#
# to check if a rule matched, do: `"TCP client" in matches`.
# to find where a rule matched, do: `map(first, matches["TCP client"])`
# to see how a rule matched, do:
#
# for address, match_details in matches["TCP client"]:
# inspect(match_details)
#
# aliased here so that the type can be documented and xref'd.
MatchResults = Mapping[str, List[Tuple[Address, Result]]]
def index_rule_matches(features: FeatureSet, rule: "capa.rules.Rule", locations: Iterable[Address]):
def topologically_order_rules(rules):
"""
record into the given featureset that the given rule matched at the given locations.
order the given rules such that dependencies show up before dependents.
this means that as we match rules, we can add features for the matches, and these
will be matched by subsequent rules if they follow this order.
naively, this is just adding a MatchedRule feature;
however, we also want to record matches for the rule's namespaces.
updates `features` in-place. doesn't modify the remaining arguments.
assumes that the rule dependency graph is a DAG.
"""
features[capa.features.common.MatchedRule(rule.name)].update(locations)
namespace = rule.meta.get("namespace")
if namespace:
while namespace:
features[capa.features.common.MatchedRule(namespace)].update(locations)
namespace, _, _ = namespace.rpartition("/")
# we evaluate `rules` multiple times, so if its a generator, realize it into a list.
rules = list(rules)
namespaces = capa.rules.index_rules_by_namespace(rules)
rules = {rule.name: rule for rule in rules}
seen = set([])
ret = []
def rec(rule):
if rule.name in seen:
return
for dep in rule.get_dependencies(namespaces):
rec(rules[dep])
ret.append(rule)
seen.add(rule.name)
for rule in rules.values():
rec(rule)
return ret
def match(rules: List["capa.rules.Rule"], features: FeatureSet, addr: Address) -> Tuple[FeatureSet, MatchResults]:
def match(rules, features, va):
"""
match the given rules against the given features,
returning an updated set of features and the matches.
Args:
rules (List[capa.rules.Rule]): these must already be ordered topologically by dependency.
features (Mapping[capa.features.Feature, int]):
va (int): location of the features
the updated features are just like the input,
but extended to include the match features (e.g. names of rules that matched).
the given feature set is not modified; an updated copy is returned.
the given list of rules must be ordered topologically by dependency,
or else `match` statements will not be handled correctly.
this routine should be fairly optimized, but is not guaranteed to be the fastest matcher possible.
it has a particularly convenient signature: (rules, features) -> matches
other strategies can be imagined that match differently; implement these elsewhere.
specifically, this routine does "top down" matching of the given rules against the feature set.
Returns:
Tuple[List[capa.features.Feature], Dict[str, Tuple[int, capa.engine.Result]]]: two-tuple with entries:
- list of features used for matching (which may be greater than argument, due to rule match features), and
- mapping from rule name to (location of match, result object)
"""
results: MatchResults = collections.defaultdict(list)
results = collections.defaultdict(list)
# copy features so that we can modify it
# without affecting the caller (keep this function pure)
@@ -313,22 +251,15 @@ def match(rules: List["capa.rules.Rule"], features: FeatureSet, addr: Address) -
features = collections.defaultdict(set, copy.copy(features))
for rule in rules:
res = rule.evaluate(features, short_circuit=True)
res = rule.evaluate(features)
if res:
# we first matched the rule with short circuiting enabled.
# this is much faster than without short circuiting.
# however, we want to collect all results thoroughly,
# so once we've found a match quickly,
# go back and capture results without short circuiting.
res = rule.evaluate(features, short_circuit=False)
results[rule.name].append((va, res))
features[capa.features.MatchedRule(rule.name)].add(va)
# sanity check
assert bool(res) is True
results[rule.name].append((addr, res))
# we need to update the current `features`
# because subsequent iterations of this loop may use newly added features,
# such as rule or namespace matches.
index_rule_matches(features, rule, [addr])
namespace = rule.meta.get("namespace")
if namespace:
while namespace:
features[capa.features.MatchedRule(namespace)].add(va)
namespace, _, _ = namespace.rpartition("/")
return (features, results)

View File

@@ -1,25 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
class UnsupportedRuntimeError(RuntimeError):
pass
class UnsupportedFormatError(ValueError):
pass
class UnsupportedArchError(ValueError):
pass
class UnsupportedOSError(ValueError):
pass
class EmptyReportError(ValueError):
pass

View File

@@ -0,0 +1,222 @@
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import re
import sys
import codecs
import logging
import capa.engine
logger = logging.getLogger(__name__)
MAX_BYTES_FEATURE_SIZE = 0x100
# thunks may be chained so we specify a delta to control the depth to which these chains are explored
THUNK_CHAIN_DEPTH_DELTA = 5
# identifiers for supported architectures names that tweak a feature
# for example, offset/x32
ARCH_X32 = "x32"
ARCH_X64 = "x64"
VALID_ARCH = (ARCH_X32, ARCH_X64)
def bytes_to_str(b):
if sys.version_info[0] >= 3:
return str(codecs.encode(b, "hex").decode("utf-8"))
else:
return codecs.encode(b, "hex")
def hex_string(h):
""" render hex string e.g. "0a40b1" as "0A 40 B1" """
return " ".join(h[i : i + 2] for i in range(0, len(h), 2)).upper()
class Feature(object):
def __init__(self, value, arch=None, description=None):
"""
Args:
value (any): the value of the feature, such as the number or string.
arch (str): one of the VALID_ARCH values, or None.
When None, then the feature applies to any architecture.
Modifies the feature name from `feature` to `feature/arch`, like `offset/x32`.
description (str): a human-readable description that explains the feature value.
"""
super(Feature, self).__init__()
if arch is not None:
if arch not in VALID_ARCH:
raise ValueError("arch '%s' must be one of %s" % (arch, VALID_ARCH))
self.name = self.__class__.__name__.lower() + "/" + arch
else:
self.name = self.__class__.__name__.lower()
self.value = value
self.arch = arch
self.description = description
def __hash__(self):
return hash((self.name, self.value, self.arch))
def __eq__(self, other):
return self.name == other.name and self.value == other.value and self.arch == other.arch
def get_value_str(self):
"""
render the value of this feature, for use by `__str__` and friends.
subclasses should override to customize the rendering.
Returns: any
"""
return self.value
def __str__(self):
if self.value is not None:
if self.description:
return "%s(%s = %s)" % (self.name, self.get_value_str(), self.description)
else:
return "%s(%s)" % (self.name, self.get_value_str())
else:
return "%s" % self.name
def __repr__(self):
return str(self)
def evaluate(self, ctx):
return capa.engine.Result(self in ctx, self, [], locations=ctx.get(self, []))
def freeze_serialize(self):
if self.arch is not None:
return (self.__class__.__name__, [self.value, {"arch": self.arch}])
else:
return (self.__class__.__name__, [self.value])
@classmethod
def freeze_deserialize(cls, args):
# as you can see below in code,
# if the last argument is a dictionary,
# consider it to be kwargs passed to the feature constructor.
if len(args) == 1:
return cls(*args)
elif isinstance(args[-1], dict):
kwargs = args[-1]
args = args[:-1]
return cls(*args, **kwargs)
class MatchedRule(Feature):
def __init__(self, value, description=None):
super(MatchedRule, self).__init__(value, description=description)
self.name = "match"
class Characteristic(Feature):
def __init__(self, value, description=None):
super(Characteristic, self).__init__(value, description=description)
class String(Feature):
def __init__(self, value, description=None):
super(String, self).__init__(value, description=description)
class Regex(String):
def __init__(self, value, description=None):
super(Regex, self).__init__(value, description=description)
pat = self.value[len("/") : -len("/")]
flags = re.DOTALL
if value.endswith("/i"):
pat = self.value[len("/") : -len("/i")]
flags |= re.IGNORECASE
try:
self.re = re.compile(pat, flags)
except re.error:
if value.endswith("/i"):
value = value[: -len("i")]
raise ValueError(
"invalid regular expression: %s it should use Python syntax, try it at https://pythex.org" % value
)
def evaluate(self, ctx):
for feature, locations in ctx.items():
if not isinstance(feature, (capa.features.String,)):
continue
# `re.search` finds a match anywhere in the given string
# which implies leading and/or trailing whitespace.
# using this mode cleans is more convenient for rule authors,
# so that they don't have to prefix/suffix their terms like: /.*foo.*/.
if self.re.search(feature.value):
# unlike other features, we cannot return put a reference to `self` directly in a `Result`.
# this is because `self` may match on many strings, so we can't stuff the matched value into it.
# instead, return a new instance that has a reference to both the regex and the matched value.
# see #262.
return capa.engine.Result(True, _MatchedRegex(self, feature.value), [], locations=locations)
return capa.engine.Result(False, _MatchedRegex(self, None), [])
def __str__(self):
return "regex(string =~ %s)" % self.value
class _MatchedRegex(Regex):
"""
this represents a specific instance of a regular expression feature match.
treat it the same as a `Regex` except it has the `match` field that contains the complete string that matched.
note: this type should only ever be constructed by `Regex.evaluate()`. it is not part of the public API.
"""
def __init__(self, regex, match):
"""
args:
regex (Regex): the regex feature that matches
match (string|None): the matching string or None if it doesn't match
"""
super(_MatchedRegex, self).__init__(regex.value, description=regex.description)
# we want this to collide with the name of `Regex` above,
# so that it works nicely with the renderers.
self.name = "regex"
# this may be None if the regex doesn't match
self.match = match
def __str__(self):
return 'regex(string =~ %s, matched = "%s")' % (self.value, self.match)
class StringFactory(object):
def __new__(self, value, description=None):
if value.startswith("/") and (value.endswith("/") or value.endswith("/i")):
return Regex(value, description=description)
return String(value, description=description)
class Bytes(Feature):
def __init__(self, value, description=None):
super(Bytes, self).__init__(value, description=description)
def evaluate(self, ctx):
for feature, locations in ctx.items():
if not isinstance(feature, (capa.features.Bytes,)):
continue
if feature.value.startswith(self.value):
return capa.engine.Result(True, self, [], locations=locations)
return capa.engine.Result(False, self, [])
def get_value_str(self):
return hex_string(bytes_to_str(self.value))
def freeze_serialize(self):
return (self.__class__.__name__, [bytes_to_str(self.value).upper()])
@classmethod
def freeze_deserialize(cls, args):
return cls(*[codecs.decode(x, "hex") for x in args])

View File

@@ -1,193 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import abc
class Address(abc.ABC):
@abc.abstractmethod
def __eq__(self, other): ...
@abc.abstractmethod
def __lt__(self, other):
# implement < so that addresses can be sorted from low to high
...
@abc.abstractmethod
def __hash__(self):
# implement hash so that addresses can be used in sets and dicts
...
@abc.abstractmethod
def __repr__(self):
# implement repr to help during debugging
...
class AbsoluteVirtualAddress(int, Address):
"""an absolute memory address"""
def __new__(cls, v):
assert v >= 0
return int.__new__(cls, v)
def __repr__(self):
return f"absolute(0x{self:x})"
def __hash__(self):
return int.__hash__(self)
class ProcessAddress(Address):
"""an address of a process in a dynamic execution trace"""
def __init__(self, pid: int, ppid: int = 0):
assert ppid >= 0
assert pid > 0
self.ppid = ppid
self.pid = pid
def __repr__(self):
return "process(%s%s)" % (
f"ppid: {self.ppid}, " if self.ppid > 0 else "",
f"pid: {self.pid}",
)
def __hash__(self):
return hash((self.ppid, self.pid))
def __eq__(self, other):
assert isinstance(other, ProcessAddress)
return (self.ppid, self.pid) == (other.ppid, other.pid)
def __lt__(self, other):
assert isinstance(other, ProcessAddress)
return (self.ppid, self.pid) < (other.ppid, other.pid)
class ThreadAddress(Address):
"""addresses a thread in a dynamic execution trace"""
def __init__(self, process: ProcessAddress, tid: int):
assert tid >= 0
self.process = process
self.tid = tid
def __repr__(self):
return f"{self.process}, thread(tid: {self.tid})"
def __hash__(self):
return hash((self.process, self.tid))
def __eq__(self, other):
assert isinstance(other, ThreadAddress)
return (self.process, self.tid) == (other.process, other.tid)
def __lt__(self, other):
assert isinstance(other, ThreadAddress)
return (self.process, self.tid) < (other.process, other.tid)
class DynamicCallAddress(Address):
"""addesses a call in a dynamic execution trace"""
def __init__(self, thread: ThreadAddress, id: int):
assert id >= 0
self.thread = thread
self.id = id
def __repr__(self):
return f"{self.thread}, call(id: {self.id})"
def __hash__(self):
return hash((self.thread, self.id))
def __eq__(self, other):
assert isinstance(other, DynamicCallAddress)
return (self.thread, self.id) == (other.thread, other.id)
def __lt__(self, other):
assert isinstance(other, DynamicCallAddress)
return (self.thread, self.id) < (other.thread, other.id)
class RelativeVirtualAddress(int, Address):
"""a memory address relative to a base address"""
def __repr__(self):
return f"relative(0x{self:x})"
def __hash__(self):
return int.__hash__(self)
class FileOffsetAddress(int, Address):
"""an address relative to the start of a file"""
def __new__(cls, v):
assert v >= 0
return int.__new__(cls, v)
def __repr__(self):
return f"file(0x{self:x})"
def __hash__(self):
return int.__hash__(self)
class DNTokenAddress(int, Address):
"""a .NET token"""
def __new__(cls, token: int):
return int.__new__(cls, token)
def __repr__(self):
return f"token(0x{self:x})"
def __hash__(self):
return int.__hash__(self)
class DNTokenOffsetAddress(Address):
"""an offset into an object specified by a .NET token"""
def __init__(self, token: int, offset: int):
assert offset >= 0
self.token = token
self.offset = offset
def __eq__(self, other):
return (self.token, self.offset) == (other.token, other.offset)
def __lt__(self, other):
return (self.token, self.offset) < (other.token, other.offset)
def __hash__(self):
return hash((self.token, self.offset))
def __repr__(self):
return f"token(0x{self.token:x})+(0x{self.offset:x})"
def __index__(self):
return self.token + self.offset
class _NoAddress(Address):
def __eq__(self, other):
return True
def __lt__(self, other):
return False
def __hash__(self):
return hash(0)
def __repr__(self):
return "no address"
NO_ADDRESS = _NoAddress()

View File

@@ -1,4 +1,4 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
@@ -6,15 +6,22 @@
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from capa.features.common import Feature
from capa.features import Feature
class BasicBlock(Feature):
def __init__(self, description=None):
super().__init__(0, description=description)
def __init__(self):
super(BasicBlock, self).__init__(None)
def __str__(self):
return "basic block"
def get_value_str(self):
return ""
def freeze_serialize(self):
return (self.__class__.__name__, [])
@classmethod
def freeze_deserialize(cls, args):
return cls()

View File

@@ -1,36 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from enum import Enum
from typing import Dict, List
from capa.helpers import assert_never
class ComType(Enum):
CLASS = "class"
INTERFACE = "interface"
COM_PREFIXES = {
ComType.CLASS: "CLSID_",
ComType.INTERFACE: "IID_",
}
def load_com_database(com_type: ComType) -> Dict[str, List[str]]:
# lazy load these python files since they are so large.
# that is, don't load them unless a COM feature is being handled.
import capa.features.com.classes
import capa.features.com.interfaces
if com_type == ComType.CLASS:
return capa.features.com.classes.COM_CLASSES
elif com_type == ComType.INTERFACE:
return capa.features.com.interfaces.COM_INTERFACES
else:
assert_never(com_type)

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File diff suppressed because it is too large Load Diff

View File

@@ -1,491 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import re
import abc
import codecs
import typing
import logging
import collections
from typing import TYPE_CHECKING, Set, Dict, List, Union, Optional
if TYPE_CHECKING:
# circular import, otherwise
import capa.engine
import capa.perf
import capa.features
import capa.features.extractors.elf
from capa.features.address import Address
logger = logging.getLogger(__name__)
MAX_BYTES_FEATURE_SIZE = 0x100
# thunks may be chained so we specify a delta to control the depth to which these chains are explored
THUNK_CHAIN_DEPTH_DELTA = 5
class FeatureAccess:
READ = "read"
WRITE = "write"
VALID_FEATURE_ACCESS = (FeatureAccess.READ, FeatureAccess.WRITE)
def bytes_to_str(b: bytes) -> str:
return str(codecs.encode(b, "hex").decode("utf-8"))
def hex_string(h: str) -> str:
"""render hex string e.g. "0a40b1" as "0A 40 B1" """
return " ".join(h[i : i + 2] for i in range(0, len(h), 2)).upper()
def escape_string(s: str) -> str:
"""escape special characters"""
s = repr(s)
if not s.startswith(('"', "'")):
# u'hello\r\nworld' -> hello\\r\\nworld
s = s[2:-1]
else:
# 'hello\r\nworld' -> hello\\r\\nworld
s = s[1:-1]
s = s.replace("\\'", "'") # repr() may escape "'" in some edge cases, remove
s = s.replace('"', '\\"') # repr() does not escape '"', add
return s
class Result:
"""
represents the results of an evaluation of statements against features.
instances of this class should behave like a bool,
e.g. `assert Result(True, ...) == True`
instances track additional metadata about evaluation results.
they contain references to the statement node (e.g. an And statement),
as well as the children Result instances.
we need this so that we can render the tree of expressions and their results.
"""
def __init__(
self,
success: bool,
statement: Union["capa.engine.Statement", "Feature"],
children: List["Result"],
locations: Optional[Set[Address]] = None,
):
super().__init__()
self.success = success
self.statement = statement
self.children = children
self.locations = locations if locations is not None else set()
def __eq__(self, other):
if isinstance(other, bool):
return self.success == other
return False
def __bool__(self):
return self.success
def __nonzero__(self):
return self.success
class Feature(abc.ABC): # noqa: B024
# this is an abstract class, since we don't want anyone to instantiate it directly,
# but it doesn't have any abstract methods.
def __init__(
self,
value: Union[str, int, float, bytes],
description: Optional[str] = None,
):
"""
Args:
value (any): the value of the feature, such as the number or string.
description (str): a human-readable description that explains the feature value.
"""
super().__init__()
self.name = self.__class__.__name__.lower()
self.value = value
self.description = description
def __hash__(self):
return hash((self.name, self.value))
def __eq__(self, other):
return self.name == other.name and self.value == other.value
def __lt__(self, other):
# implementing sorting by serializing to JSON is a huge hack.
# its slow, inelegant, and probably doesn't work intuitively;
# however, we only use it for deterministic output, so it's good enough for now.
# circular import
# we should fix if this wasn't already a huge hack.
import capa.features.freeze.features
return (
capa.features.freeze.features.feature_from_capa(self).model_dump_json()
< capa.features.freeze.features.feature_from_capa(other).model_dump_json()
)
def get_name_str(self) -> str:
"""
render the name of this feature, for use by `__str__` and friends.
subclasses should override to customize the rendering.
"""
return self.name
def get_value_str(self) -> str:
"""
render the value of this feature, for use by `__str__` and friends.
subclasses should override to customize the rendering.
"""
return str(self.value)
def __str__(self):
if self.value is not None:
if self.description:
return f"{self.get_name_str()}({self.get_value_str()} = {self.description})"
else:
return f"{self.get_name_str()}({self.get_value_str()})"
else:
return f"{self.get_name_str()}"
def __repr__(self):
return str(self)
def evaluate(self, ctx: Dict["Feature", Set[Address]], **kwargs) -> Result:
capa.perf.counters["evaluate.feature"] += 1
capa.perf.counters["evaluate.feature." + self.name] += 1
return Result(self in ctx, self, [], locations=ctx.get(self, set()))
class MatchedRule(Feature):
def __init__(self, value: str, description=None):
super().__init__(value, description=description)
self.name = "match"
class Characteristic(Feature):
def __init__(self, value: str, description=None):
super().__init__(value, description=description)
class String(Feature):
def __init__(self, value: str, description=None):
super().__init__(value, description=description)
def get_value_str(self) -> str:
assert isinstance(self.value, str)
return escape_string(self.value)
class Class(Feature):
def __init__(self, value: str, description=None):
super().__init__(value, description=description)
class Namespace(Feature):
def __init__(self, value: str, description=None):
super().__init__(value, description=description)
class Substring(String):
def __init__(self, value: str, description=None):
super().__init__(value, description=description)
self.value = value
def evaluate(self, ctx, short_circuit=True):
capa.perf.counters["evaluate.feature"] += 1
capa.perf.counters["evaluate.feature.substring"] += 1
# mapping from string value to list of locations.
# will unique the locations later on.
matches: typing.DefaultDict[str, Set[Address]] = collections.defaultdict(set)
assert isinstance(self.value, str)
for feature, locations in ctx.items():
if not isinstance(feature, (String,)):
continue
if not isinstance(feature.value, str):
# this is a programming error: String should only contain str
raise ValueError("unexpected feature value type")
if self.value in feature.value:
matches[feature.value].update(locations)
if short_circuit:
# we found one matching string, thats sufficient to match.
# don't collect other matching strings in this mode.
break
if matches:
# collect all locations
locations = set()
for locs in matches.values():
locations.update(locs)
# unlike other features, we cannot return put a reference to `self` directly in a `Result`.
# this is because `self` may match on many strings, so we can't stuff the matched value into it.
# instead, return a new instance that has a reference to both the substring and the matched values.
return Result(True, _MatchedSubstring(self, dict(matches)), [], locations=locations)
else:
return Result(False, _MatchedSubstring(self, {}), [])
def get_value_str(self) -> str:
assert isinstance(self.value, str)
return escape_string(self.value)
def __str__(self):
assert isinstance(self.value, str)
return f"substring({escape_string(self.value)})"
class _MatchedSubstring(Substring):
"""
this represents specific match instances of a substring feature.
treat it the same as a `Substring` except it has the `matches` field that contains the complete strings that matched.
note: this type should only ever be constructed by `Substring.evaluate()`. it is not part of the public API.
"""
def __init__(self, substring: Substring, matches: Dict[str, Set[Address]]):
"""
args:
substring: the substring feature that matches.
match: mapping from matching string to its locations.
"""
super().__init__(str(substring.value), description=substring.description)
# we want this to collide with the name of `Substring` above,
# so that it works nicely with the renderers.
self.name = "substring"
# this may be None if the substring doesn't match
self.matches = matches
def __str__(self):
matches = ", ".join(f'"{s}"' for s in (self.matches or {}).keys())
assert isinstance(self.value, str)
return f'substring("{self.value}", matches = {matches})'
class Regex(String):
def __init__(self, value: str, description=None):
super().__init__(value, description=description)
self.value = value
pat = self.value[len("/") : -len("/")]
flags = re.DOTALL
if value.endswith("/i"):
pat = self.value[len("/") : -len("/i")]
flags |= re.IGNORECASE
try:
self.re = re.compile(pat, flags)
except re.error as exc:
if value.endswith("/i"):
value = value[: -len("i")]
raise ValueError(
f"invalid regular expression: {value} it should use Python syntax, try it at https://pythex.org"
) from exc
def evaluate(self, ctx, short_circuit=True):
capa.perf.counters["evaluate.feature"] += 1
capa.perf.counters["evaluate.feature.regex"] += 1
# mapping from string value to list of locations.
# will unique the locations later on.
matches: typing.DefaultDict[str, Set[Address]] = collections.defaultdict(set)
for feature, locations in ctx.items():
if not isinstance(feature, (String,)):
continue
if not isinstance(feature.value, str):
# this is a programming error: String should only contain str
raise ValueError("unexpected feature value type")
# `re.search` finds a match anywhere in the given string
# which implies leading and/or trailing whitespace.
# using this mode cleans is more convenient for rule authors,
# so that they don't have to prefix/suffix their terms like: /.*foo.*/.
if self.re.search(feature.value):
matches[feature.value].update(locations)
if short_circuit:
# we found one matching string, thats sufficient to match.
# don't collect other matching strings in this mode.
break
if matches:
# collect all locations
locations = set()
for locs in matches.values():
locations.update(locs)
# unlike other features, we cannot return put a reference to `self` directly in a `Result`.
# this is because `self` may match on many strings, so we can't stuff the matched value into it.
# instead, return a new instance that has a reference to both the regex and the matched values.
# see #262.
return Result(True, _MatchedRegex(self, dict(matches)), [], locations=locations)
else:
return Result(False, _MatchedRegex(self, {}), [])
def __str__(self):
assert isinstance(self.value, str)
return f"regex(string =~ {self.value})"
class _MatchedRegex(Regex):
"""
this represents specific match instances of a regular expression feature.
treat it the same as a `Regex` except it has the `matches` field that contains the complete strings that matched.
note: this type should only ever be constructed by `Regex.evaluate()`. it is not part of the public API.
"""
def __init__(self, regex: Regex, matches: Dict[str, Set[Address]]):
"""
args:
regex: the regex feature that matches.
matches: mapping from matching string to its locations.
"""
super().__init__(str(regex.value), description=regex.description)
# we want this to collide with the name of `Regex` above,
# so that it works nicely with the renderers.
self.name = "regex"
# this may be None if the regex doesn't match
self.matches = matches
def __str__(self):
matches = ", ".join(f'"{s}"' for s in (self.matches or {}).keys())
assert isinstance(self.value, str)
return f"regex(string =~ {self.value}, matches = {matches})"
class StringFactory:
def __new__(cls, value: str, description=None):
if value.startswith("/") and (value.endswith("/") or value.endswith("/i")):
return Regex(value, description=description)
return String(value, description=description)
class Bytes(Feature):
def __init__(self, value: bytes, description=None):
super().__init__(value, description=description)
self.value = value
def evaluate(self, ctx, **kwargs):
capa.perf.counters["evaluate.feature"] += 1
capa.perf.counters["evaluate.feature.bytes"] += 1
assert isinstance(self.value, bytes)
for feature, locations in ctx.items():
if not isinstance(feature, (Bytes,)):
continue
assert isinstance(feature.value, bytes)
if feature.value.startswith(self.value):
return Result(True, self, [], locations=locations)
return Result(False, self, [])
def get_value_str(self):
assert isinstance(self.value, bytes)
return hex_string(bytes_to_str(self.value))
# other candidates here: https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#machine-types
ARCH_I386 = "i386"
ARCH_AMD64 = "amd64"
# dotnet
ARCH_ANY = "any"
VALID_ARCH = (ARCH_I386, ARCH_AMD64, ARCH_ANY)
class Arch(Feature):
def __init__(self, value: str, description=None):
super().__init__(value, description=description)
self.name = "arch"
OS_WINDOWS = "windows"
OS_LINUX = "linux"
OS_MACOS = "macos"
# dotnet
OS_ANY = "any"
VALID_OS = {os.value for os in capa.features.extractors.elf.OS}
VALID_OS.update({OS_WINDOWS, OS_LINUX, OS_MACOS, OS_ANY})
# internal only, not to be used in rules
OS_AUTO = "auto"
class OS(Feature):
def __init__(self, value: str, description=None):
super().__init__(value, description=description)
self.name = "os"
def evaluate(self, ctx, **kwargs):
capa.perf.counters["evaluate.feature"] += 1
capa.perf.counters["evaluate.feature." + self.name] += 1
for feature, locations in ctx.items():
if not isinstance(feature, (OS,)):
continue
assert isinstance(feature.value, str)
if OS_ANY in (self.value, feature.value) or self.value == feature.value:
return Result(True, self, [], locations=locations)
return Result(False, self, [])
FORMAT_PE = "pe"
FORMAT_ELF = "elf"
FORMAT_DOTNET = "dotnet"
VALID_FORMAT = (FORMAT_PE, FORMAT_ELF, FORMAT_DOTNET)
# internal only, not to be used in rules
FORMAT_AUTO = "auto"
FORMAT_SC32 = "sc32"
FORMAT_SC64 = "sc64"
FORMAT_CAPE = "cape"
FORMAT_FREEZE = "freeze"
FORMAT_RESULT = "result"
STATIC_FORMATS = {
FORMAT_SC32,
FORMAT_SC64,
FORMAT_PE,
FORMAT_ELF,
FORMAT_DOTNET,
FORMAT_FREEZE,
FORMAT_RESULT,
}
DYNAMIC_FORMATS = {
FORMAT_CAPE,
FORMAT_FREEZE,
FORMAT_RESULT,
}
FORMAT_UNKNOWN = "unknown"
class Format(Feature):
def __init__(self, value: str, description=None):
super().__init__(value, description=description)
self.name = "format"
def is_global_feature(feature):
"""
is this a feature that is extracted at every scope?
today, these are OS and arch features.
"""
return isinstance(feature, (OS, Arch))

View File

@@ -0,0 +1,294 @@
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import abc
from capa.helpers import oint
class FeatureExtractor(object):
"""
FeatureExtractor defines the interface for fetching features from a sample.
There may be multiple backends that support fetching features for capa.
For example, we use vivisect by default, but also want to support saving
and restoring features from a JSON file.
When we restore the features, we'd like to use exactly the same matching logic
to find matching rules.
Therefore, we can define a FeatureExtractor that provides features from the
serialized JSON file and do matching without a binary analysis pass.
Also, this provides a way to hook in an IDA backend.
This class is not instantiated directly; it is the base class for other implementations.
"""
__metaclass__ = abc.ABCMeta
def __init__(self):
#
# note: a subclass should define ctor parameters for its own use.
# for example, the Vivisect feature extract might require the vw and/or path.
# this base class doesn't know what to do with that info, though.
#
super(FeatureExtractor, self).__init__()
def block_offset(self, bb):
return oint(bb)
def function_offset(self, f):
return oint(f)
@abc.abstractmethod
def get_base_address(self):
"""
fetch the preferred load address at which the sample was analyzed.
returns: int
"""
raise NotImplemented
@abc.abstractmethod
def extract_file_features(self):
"""
extract file-scope features.
example::
extractor = VivisectFeatureExtractor(vw, path)
for feature, va in extractor.get_file_features():
print('0x%x: %s', va, feature)
yields:
Tuple[capa.features.Feature, int]: feature and its location
"""
raise NotImplemented
@abc.abstractmethod
def get_functions(self):
"""
enumerate the functions and provide opaque values that will
subsequently be provided to `.extract_function_features()`, etc.
by "opaque value", we mean that this can be any object, as long as it
provides enough context to `.extract_function_features()`.
the opaque value should support casting to int (`__int__`) for the function start address.
yields:
any: the opaque function value.
"""
raise NotImplemented
@abc.abstractmethod
def extract_function_features(self, f):
"""
extract function-scope features.
the arguments are opaque values previously provided by `.get_functions()`, etc.
example::
extractor = VivisectFeatureExtractor(vw, path)
for function in extractor.get_functions():
for feature, va in extractor.extract_function_features(function):
print('0x%x: %s', va, feature)
args:
f [any]: an opaque value previously fetched from `.get_functions()`.
yields:
Tuple[capa.features.Feature, int]: feature and its location
"""
raise NotImplemented
@abc.abstractmethod
def get_basic_blocks(self, f):
"""
enumerate the basic blocks in the given function and provide opaque values that will
subsequently be provided to `.extract_basic_block_features()`, etc.
by "opaque value", we mean that this can be any object, as long as it
provides enough context to `.extract_basic_block_features()`.
the opaque value should support casting to int (`__int__`) for the basic block start address.
yields:
any: the opaque basic block value.
"""
raise NotImplemented
@abc.abstractmethod
def extract_basic_block_features(self, f, bb):
"""
extract basic block-scope features.
the arguments are opaque values previously provided by `.get_functions()`, etc.
example::
extractor = VivisectFeatureExtractor(vw, path)
for function in extractor.get_functions():
for bb in extractor.get_basic_blocks(function):
for feature, va in extractor.extract_basic_block_features(function, bb):
print('0x%x: %s', va, feature)
args:
f [any]: an opaque value previously fetched from `.get_functions()`.
bb [any]: an opaque value previously fetched from `.get_basic_blocks()`.
yields:
Tuple[capa.features.Feature, int]: feature and its location
"""
raise NotImplemented
@abc.abstractmethod
def get_instructions(self, f, bb):
"""
enumerate the instructions in the given basic block and provide opaque values that will
subsequently be provided to `.extract_insn_features()`, etc.
by "opaque value", we mean that this can be any object, as long as it
provides enough context to `.extract_insn_features()`.
the opaque value should support casting to int (`__int__`) for the instruction address.
yields:
any: the opaque function value.
"""
raise NotImplemented
@abc.abstractmethod
def extract_insn_features(self, f, bb, insn):
"""
extract instruction-scope features.
the arguments are opaque values previously provided by `.get_functions()`, etc.
example::
extractor = VivisectFeatureExtractor(vw, path)
for function in extractor.get_functions():
for bb in extractor.get_basic_blocks(function):
for insn in extractor.get_instructions(function, bb):
for feature, va in extractor.extract_insn_features(function, bb, insn):
print('0x%x: %s', va, feature)
args:
f [any]: an opaque value previously fetched from `.get_functions()`.
bb [any]: an opaque value previously fetched from `.get_basic_blocks()`.
insn [any]: an opaque value previously fetched from `.get_instructions()`.
yields:
Tuple[capa.features.Feature, int]: feature and its location
"""
raise NotImplemented
class NullFeatureExtractor(FeatureExtractor):
"""
An extractor that extracts some user-provided features.
The structure of the single parameter is demonstrated in the example below.
This is useful for testing, as we can provide expected values and see if matching works.
Also, this is how we represent features deserialized from a freeze file.
example::
extractor = NullFeatureExtractor({
'base address: 0x401000,
'file features': [
(0x402345, capa.features.Characteristic('embedded pe')),
],
'functions': {
0x401000: {
'features': [
(0x401000, capa.features.Characteristic('nzxor')),
],
'basic blocks': {
0x401000: {
'features': [
(0x401000, capa.features.Characteristic('tight-loop')),
],
'instructions': {
0x401000: {
'features': [
(0x401000, capa.features.Characteristic('nzxor')),
],
},
0x401002: ...
}
},
0x401005: ...
}
},
0x40200: ...
}
)
"""
def __init__(self, features):
super(NullFeatureExtractor, self).__init__()
self.features = features
def get_base_address(self):
return self.features["base address"]
def extract_file_features(self):
for p in self.features.get("file features", []):
va, feature = p
yield feature, va
def get_functions(self):
for va in sorted(self.features["functions"].keys()):
yield va
def extract_function_features(self, f):
for p in self.features.get("functions", {}).get(f, {}).get("features", []): # noqa: E127 line over-indented
va, feature = p
yield feature, va
def get_basic_blocks(self, f):
for va in sorted(
self.features.get("functions", {}) # noqa: E127 line over-indented
.get(f, {})
.get("basic blocks", {})
.keys()
):
yield va
def extract_basic_block_features(self, f, bb):
for p in (
self.features.get("functions", {}) # noqa: E127 line over-indented
.get(f, {})
.get("basic blocks", {})
.get(bb, {})
.get("features", [])
):
va, feature = p
yield feature, va
def get_instructions(self, f, bb):
for va in sorted(
self.features.get("functions", {}) # noqa: E127 line over-indented
.get(f, {})
.get("basic blocks", {})
.get(bb, {})
.get("instructions", {})
.keys()
):
yield va
def extract_insn_features(self, f, bb, insn):
for p in (
self.features.get("functions", {}) # noqa: E127 line over-indented
.get(f, {})
.get("basic blocks", {})
.get(bb, {})
.get("instructions", {})
.get(insn, {})
.get("features", [])
):
va, feature = p
yield feature, va

View File

@@ -1,470 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import abc
import hashlib
import dataclasses
from typing import Any, Dict, Tuple, Union, Iterator
from dataclasses import dataclass
# TODO(williballenthin): use typing.TypeAlias directly when Python 3.9 is deprecated
# https://github.com/mandiant/capa/issues/1699
from typing_extensions import TypeAlias
import capa.features.address
from capa.features.common import Feature
from capa.features.address import Address, ThreadAddress, ProcessAddress, DynamicCallAddress, AbsoluteVirtualAddress
# feature extractors may reference functions, BBs, insns by opaque handle values.
# you can use the `.address` property to get and render the address of the feature.
#
# these handles are only consumed by routines on
# the feature extractor from which they were created.
@dataclass
class SampleHashes:
md5: str
sha1: str
sha256: str
@classmethod
def from_bytes(cls, buf: bytes) -> "SampleHashes":
md5 = hashlib.md5()
sha1 = hashlib.sha1()
sha256 = hashlib.sha256()
md5.update(buf)
sha1.update(buf)
sha256.update(buf)
return cls(md5=md5.hexdigest(), sha1=sha1.hexdigest(), sha256=sha256.hexdigest())
@dataclass
class FunctionHandle:
"""reference to a function recognized by a feature extractor.
Attributes:
address: the address of the function.
inner: extractor-specific data.
ctx: a context object for the extractor.
"""
address: Address
inner: Any
ctx: Dict[str, Any] = dataclasses.field(default_factory=dict)
@dataclass
class BBHandle:
"""reference to a basic block recognized by a feature extractor.
Attributes:
address: the address of the basic block start address.
inner: extractor-specific data.
"""
address: Address
inner: Any
@dataclass
class InsnHandle:
"""reference to a instruction recognized by a feature extractor.
Attributes:
address: the address of the instruction address.
inner: extractor-specific data.
"""
address: Address
inner: Any
class StaticFeatureExtractor:
"""
StaticFeatureExtractor defines the interface for fetching features from a
sample without running it; extractors that rely on the execution trace of
a sample must implement the other sibling class, DynamicFeatureExtracor.
There may be multiple backends that support fetching features for capa.
For example, we use vivisect by default, but also want to support saving
and restoring features from a JSON file.
When we restore the features, we'd like to use exactly the same matching logic
to find matching rules.
Therefore, we can define a StaticFeatureExtractor that provides features from the
serialized JSON file and do matching without a binary analysis pass.
Also, this provides a way to hook in an IDA backend.
This class is not instantiated directly; it is the base class for other implementations.
"""
__metaclass__ = abc.ABCMeta
def __init__(self, hashes: SampleHashes):
#
# note: a subclass should define ctor parameters for its own use.
# for example, the Vivisect feature extract might require the vw and/or path.
# this base class doesn't know what to do with that info, though.
#
super().__init__()
self._sample_hashes = hashes
@abc.abstractmethod
def get_base_address(self) -> Union[AbsoluteVirtualAddress, capa.features.address._NoAddress]:
"""
fetch the preferred load address at which the sample was analyzed.
when the base address is `NO_ADDRESS`, then the loader has no concept of a preferred load address.
such as: shellcode, .NET modules, etc.
in these scenarios, RelativeVirtualAddresses aren't used.
"""
raise NotImplementedError()
def get_sample_hashes(self) -> SampleHashes:
"""
fetch the hashes for the sample contained within the extractor.
"""
return self._sample_hashes
@abc.abstractmethod
def extract_global_features(self) -> Iterator[Tuple[Feature, Address]]:
"""
extract features found at every scope ("global").
example::
extractor = VivisectFeatureExtractor(vw, path)
for feature, va in extractor.get_global_features():
print('0x%x: %s', va, feature)
yields:
Tuple[Feature, Address]: feature and its location
"""
raise NotImplementedError()
@abc.abstractmethod
def extract_file_features(self) -> Iterator[Tuple[Feature, Address]]:
"""
extract file-scope features.
example::
extractor = VivisectFeatureExtractor(vw, path)
for feature, va in extractor.get_file_features():
print('0x%x: %s', va, feature)
yields:
Tuple[Feature, Address]: feature and its location
"""
raise NotImplementedError()
@abc.abstractmethod
def get_functions(self) -> Iterator[FunctionHandle]:
"""
enumerate the functions and provide opaque values that will
subsequently be provided to `.extract_function_features()`, etc.
"""
raise NotImplementedError()
def is_library_function(self, addr: Address) -> bool:
"""
is the given address a library function?
the backend may implement its own function matching algorithm, or none at all.
we accept an address here, rather than function object,
to handle addresses identified in instructions.
this information is used to:
- filter out matches in library functions (by default), and
- recognize when to fetch symbol names for called (non-API) functions
args:
addr (Address): the address of a function.
returns:
bool: True if the given address is the start of a library function.
"""
return False
def get_function_name(self, addr: Address) -> str:
"""
fetch any recognized name for the given address.
this is only guaranteed to return a value when the given function is a recognized library function.
we accept a VA here, rather than function object, to handle addresses identified in instructions.
args:
addr (Address): the address of a function.
returns:
str: the function name
raises:
KeyError: when the given function does not have a name.
"""
raise KeyError(addr)
@abc.abstractmethod
def extract_function_features(self, f: FunctionHandle) -> Iterator[Tuple[Feature, Address]]:
"""
extract function-scope features.
the arguments are opaque values previously provided by `.get_functions()`, etc.
example::
extractor = VivisectFeatureExtractor(vw, path)
for function in extractor.get_functions():
for feature, address in extractor.extract_function_features(function):
print('0x%x: %s', address, feature)
args:
f [FunctionHandle]: an opaque value previously fetched from `.get_functions()`.
yields:
Tuple[Feature, Address]: feature and its location
"""
raise NotImplementedError()
@abc.abstractmethod
def get_basic_blocks(self, f: FunctionHandle) -> Iterator[BBHandle]:
"""
enumerate the basic blocks in the given function and provide opaque values that will
subsequently be provided to `.extract_basic_block_features()`, etc.
"""
raise NotImplementedError()
@abc.abstractmethod
def extract_basic_block_features(self, f: FunctionHandle, bb: BBHandle) -> Iterator[Tuple[Feature, Address]]:
"""
extract basic block-scope features.
the arguments are opaque values previously provided by `.get_functions()`, etc.
example::
extractor = VivisectFeatureExtractor(vw, path)
for function in extractor.get_functions():
for bb in extractor.get_basic_blocks(function):
for feature, address in extractor.extract_basic_block_features(function, bb):
print('0x%x: %s', address, feature)
args:
f [FunctionHandle]: an opaque value previously fetched from `.get_functions()`.
bb [BBHandle]: an opaque value previously fetched from `.get_basic_blocks()`.
yields:
Tuple[Feature, Address]: feature and its location
"""
raise NotImplementedError()
@abc.abstractmethod
def get_instructions(self, f: FunctionHandle, bb: BBHandle) -> Iterator[InsnHandle]:
"""
enumerate the instructions in the given basic block and provide opaque values that will
subsequently be provided to `.extract_insn_features()`, etc.
"""
raise NotImplementedError()
@abc.abstractmethod
def extract_insn_features(
self, f: FunctionHandle, bb: BBHandle, insn: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""
extract instruction-scope features.
the arguments are opaque values previously provided by `.get_functions()`, etc.
example::
extractor = VivisectFeatureExtractor(vw, path)
for function in extractor.get_functions():
for bb in extractor.get_basic_blocks(function):
for insn in extractor.get_instructions(function, bb):
for feature, address in extractor.extract_insn_features(function, bb, insn):
print('0x%x: %s', address, feature)
args:
f [FunctionHandle]: an opaque value previously fetched from `.get_functions()`.
bb [BBHandle]: an opaque value previously fetched from `.get_basic_blocks()`.
insn [InsnHandle]: an opaque value previously fetched from `.get_instructions()`.
yields:
Tuple[Feature, Address]: feature and its location
"""
raise NotImplementedError()
@dataclass
class ProcessHandle:
"""
reference to a process extracted by the sandbox.
Attributes:
address: process's address (pid)
inner: sandbox-specific data
"""
address: ProcessAddress
inner: Any
@dataclass
class ThreadHandle:
"""
reference to a thread extracted by the sandbox.
Attributes:
address: thread's address (tid)
inner: sandbox-specific data
"""
address: ThreadAddress
inner: Any
@dataclass
class CallHandle:
"""
reference to an api call extracted by the sandbox.
Attributes:
address: call's address, such as event index or id
inner: sandbox-specific data
"""
address: DynamicCallAddress
inner: Any
class DynamicFeatureExtractor:
"""
DynamicFeatureExtractor defines the interface for fetching features from a
sandbox' analysis of a sample; extractors that rely on statically analyzing
a sample must implement the sibling extractor, StaticFeatureExtractor.
Features are grouped mainly into threads that alongside their meta-features are also grouped into
processes (that also have their own features). Other scopes (such as function and file) may also apply
for a specific sandbox.
This class is not instantiated directly; it is the base class for other implementations.
"""
__metaclass__ = abc.ABCMeta
def __init__(self, hashes: SampleHashes):
#
# note: a subclass should define ctor parameters for its own use.
# for example, the Vivisect feature extract might require the vw and/or path.
# this base class doesn't know what to do with that info, though.
#
super().__init__()
self._sample_hashes = hashes
def get_sample_hashes(self) -> SampleHashes:
"""
fetch the hashes for the sample contained within the extractor.
"""
return self._sample_hashes
@abc.abstractmethod
def extract_global_features(self) -> Iterator[Tuple[Feature, Address]]:
"""
extract features found at every scope ("global").
example::
extractor = CapeFeatureExtractor.from_report(json.loads(buf))
for feature, addr in extractor.get_global_features():
print(addr, feature)
yields:
Tuple[Feature, Address]: feature and its location
"""
raise NotImplementedError()
@abc.abstractmethod
def extract_file_features(self) -> Iterator[Tuple[Feature, Address]]:
"""
extract file-scope features.
example::
extractor = CapeFeatureExtractor.from_report(json.loads(buf))
for feature, addr in extractor.get_file_features():
print(addr, feature)
yields:
Tuple[Feature, Address]: feature and its location
"""
raise NotImplementedError()
@abc.abstractmethod
def get_processes(self) -> Iterator[ProcessHandle]:
"""
Enumerate processes in the trace.
"""
raise NotImplementedError()
@abc.abstractmethod
def extract_process_features(self, ph: ProcessHandle) -> Iterator[Tuple[Feature, Address]]:
"""
Yields all the features of a process. These include:
- file features of the process' image
"""
raise NotImplementedError()
@abc.abstractmethod
def get_process_name(self, ph: ProcessHandle) -> str:
"""
Returns the human-readable name for the given process,
such as the filename.
"""
raise NotImplementedError()
@abc.abstractmethod
def get_threads(self, ph: ProcessHandle) -> Iterator[ThreadHandle]:
"""
Enumerate threads in the given process.
"""
raise NotImplementedError()
@abc.abstractmethod
def extract_thread_features(self, ph: ProcessHandle, th: ThreadHandle) -> Iterator[Tuple[Feature, Address]]:
"""
Yields all the features of a thread. These include:
- sequenced api traces
"""
raise NotImplementedError()
@abc.abstractmethod
def get_calls(self, ph: ProcessHandle, th: ThreadHandle) -> Iterator[CallHandle]:
"""
Enumerate calls in the given thread
"""
raise NotImplementedError()
@abc.abstractmethod
def extract_call_features(
self, ph: ProcessHandle, th: ThreadHandle, ch: CallHandle
) -> Iterator[Tuple[Feature, Address]]:
"""
Yields all features of a call. These include:
- api name
- bytes/strings/numbers extracted from arguments
"""
raise NotImplementedError()
@abc.abstractmethod
def get_call_name(self, ph: ProcessHandle, th: ThreadHandle, ch: CallHandle) -> str:
"""
Returns the human-readable name for the given call,
such as as rendered API log entry, like:
Foo(1, "two", b"\x00\x11") -> -1
"""
raise NotImplementedError()
FeatureExtractor: TypeAlias = Union[StaticFeatureExtractor, DynamicFeatureExtractor]

View File

@@ -1,184 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import string
import struct
from typing import Tuple, Iterator
from binaryninja import Function, Settings
from binaryninja import BasicBlock as BinjaBasicBlock
from binaryninja import (
BinaryView,
SymbolType,
RegisterValueType,
VariableSourceType,
MediumLevelILSetVar,
MediumLevelILOperation,
MediumLevelILBasicBlock,
MediumLevelILInstruction,
)
from capa.features.common import Feature, Characteristic
from capa.features.address import Address
from capa.features.basicblock import BasicBlock
from capa.features.extractors.helpers import MIN_STACKSTRING_LEN
from capa.features.extractors.base_extractor import BBHandle, FunctionHandle
use_const_outline: bool = False
settings: Settings = Settings()
if settings.contains("analysis.outlining.builtins") and settings.get_bool("analysis.outlining.builtins"):
use_const_outline = True
def get_printable_len_ascii(s: bytes) -> int:
"""Return string length if all operand bytes are ascii or utf16-le printable"""
count = 0
for c in s:
if c == 0:
return count
if c < 127 and chr(c) in string.printable:
count += 1
return count
def get_printable_len_wide(s: bytes) -> int:
"""Return string length if all operand bytes are ascii or utf16-le printable"""
if all(c == 0x00 for c in s[1::2]):
return get_printable_len_ascii(s[::2])
return 0
def get_stack_string_len(f: Function, il: MediumLevelILInstruction) -> int:
bv: BinaryView = f.view
if il.operation != MediumLevelILOperation.MLIL_CALL:
return 0
target = il.dest
if target.operation not in [MediumLevelILOperation.MLIL_CONST, MediumLevelILOperation.MLIL_CONST_PTR]:
return 0
addr = target.value.value
sym = bv.get_symbol_at(addr)
if not sym or sym.type != SymbolType.LibraryFunctionSymbol:
return 0
if sym.name not in ["__builtin_strncpy", "__builtin_strcpy", "__builtin_wcscpy"]:
return 0
if len(il.params) < 2:
return 0
dest = il.params[0]
if dest.operation in [MediumLevelILOperation.MLIL_ADDRESS_OF, MediumLevelILOperation.MLIL_VAR]:
var = dest.src
else:
return 0
if var.source_type != VariableSourceType.StackVariableSourceType:
return 0
src = il.params[1]
if src.value.type != RegisterValueType.ConstantDataAggregateValue:
return 0
s = f.get_constant_data(RegisterValueType.ConstantDataAggregateValue, src.value.value)
return max(get_printable_len_ascii(bytes(s)), get_printable_len_wide(bytes(s)))
def get_printable_len(il: MediumLevelILSetVar) -> int:
"""Return string length if all operand bytes are ascii or utf16-le printable"""
width = il.dest.type.width
value = il.src.value.value
if width == 1:
chars = struct.pack("<B", value & 0xFF)
elif width == 2:
chars = struct.pack("<H", value & 0xFFFF)
elif width == 4:
chars = struct.pack("<I", value & 0xFFFFFFFF)
elif width == 8:
chars = struct.pack("<Q", value & 0xFFFFFFFFFFFFFFFF)
else:
return 0
def is_printable_ascii(chars_: bytes):
return all(c < 127 and chr(c) in string.printable for c in chars_)
def is_printable_utf16le(chars_: bytes):
if all(c == 0x00 for c in chars_[1::2]):
return is_printable_ascii(chars_[::2])
if is_printable_ascii(chars):
return width
if is_printable_utf16le(chars):
return width // 2
return 0
def is_mov_imm_to_stack(il: MediumLevelILInstruction) -> bool:
"""verify instruction moves immediate onto stack"""
if il.operation != MediumLevelILOperation.MLIL_SET_VAR:
return False
if il.src.operation != MediumLevelILOperation.MLIL_CONST:
return False
if il.dest.source_type != VariableSourceType.StackVariableSourceType:
return False
return True
def bb_contains_stackstring(f: Function, bb: MediumLevelILBasicBlock) -> bool:
"""check basic block for stackstring indicators
true if basic block contains enough moves of constant bytes to the stack
"""
count = 0
for il in bb:
if use_const_outline:
count += get_stack_string_len(f, il)
else:
if is_mov_imm_to_stack(il):
count += get_printable_len(il)
if count > MIN_STACKSTRING_LEN:
return True
return False
def extract_bb_stackstring(fh: FunctionHandle, bbh: BBHandle) -> Iterator[Tuple[Feature, Address]]:
"""extract stackstring indicators from basic block"""
bb: Tuple[BinjaBasicBlock, MediumLevelILBasicBlock] = bbh.inner
if bb[1] is not None and bb_contains_stackstring(fh.inner, bb[1]):
yield Characteristic("stack string"), bbh.address
def extract_bb_tight_loop(fh: FunctionHandle, bbh: BBHandle) -> Iterator[Tuple[Feature, Address]]:
"""extract tight loop indicators from a basic block"""
bb: Tuple[BinjaBasicBlock, MediumLevelILBasicBlock] = bbh.inner
for edge in bb[0].outgoing_edges:
if edge.target.start == bb[0].start:
yield Characteristic("tight loop"), bbh.address
def extract_features(fh: FunctionHandle, bbh: BBHandle) -> Iterator[Tuple[Feature, Address]]:
"""extract basic block features"""
for bb_handler in BASIC_BLOCK_HANDLERS:
for feature, addr in bb_handler(fh, bbh):
yield feature, addr
yield BasicBlock(), bbh.address
BASIC_BLOCK_HANDLERS = (
extract_bb_tight_loop,
extract_bb_stackstring,
)

View File

@@ -1,81 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import List, Tuple, Iterator
import binaryninja as binja
import capa.features.extractors.elf
import capa.features.extractors.binja.file
import capa.features.extractors.binja.insn
import capa.features.extractors.binja.global_
import capa.features.extractors.binja.function
import capa.features.extractors.binja.basicblock
from capa.features.common import Feature
from capa.features.address import Address, AbsoluteVirtualAddress
from capa.features.extractors.base_extractor import (
BBHandle,
InsnHandle,
SampleHashes,
FunctionHandle,
StaticFeatureExtractor,
)
class BinjaFeatureExtractor(StaticFeatureExtractor):
def __init__(self, bv: binja.BinaryView):
super().__init__(hashes=SampleHashes.from_bytes(bv.file.raw.read(0, len(bv.file.raw))))
self.bv = bv
self.global_features: List[Tuple[Feature, Address]] = []
self.global_features.extend(capa.features.extractors.binja.file.extract_file_format(self.bv))
self.global_features.extend(capa.features.extractors.binja.global_.extract_os(self.bv))
self.global_features.extend(capa.features.extractors.binja.global_.extract_arch(self.bv))
def get_base_address(self):
return AbsoluteVirtualAddress(self.bv.start)
def extract_global_features(self):
yield from self.global_features
def extract_file_features(self):
yield from capa.features.extractors.binja.file.extract_features(self.bv)
def get_functions(self) -> Iterator[FunctionHandle]:
for f in self.bv.functions:
yield FunctionHandle(address=AbsoluteVirtualAddress(f.start), inner=f)
def extract_function_features(self, fh: FunctionHandle) -> Iterator[Tuple[Feature, Address]]:
yield from capa.features.extractors.binja.function.extract_features(fh)
def get_basic_blocks(self, fh: FunctionHandle) -> Iterator[BBHandle]:
f: binja.Function = fh.inner
# Set up a MLIL basic block dict look up to associate the disassembly basic block with its MLIL basic block
mlil_lookup = {}
for mlil_bb in f.mlil.basic_blocks:
mlil_lookup[mlil_bb.source_block.start] = mlil_bb
for bb in f.basic_blocks:
mlil_bb = mlil_lookup.get(bb.start)
yield BBHandle(address=AbsoluteVirtualAddress(bb.start), inner=(bb, mlil_bb))
def extract_basic_block_features(self, fh: FunctionHandle, bbh: BBHandle) -> Iterator[Tuple[Feature, Address]]:
yield from capa.features.extractors.binja.basicblock.extract_features(fh, bbh)
def get_instructions(self, fh: FunctionHandle, bbh: BBHandle) -> Iterator[InsnHandle]:
import capa.features.extractors.binja.helpers as binja_helpers
bb: Tuple[binja.BasicBlock, binja.MediumLevelILBasicBlock] = bbh.inner
addr = bb[0].start
for text, length in bb[0]:
insn = binja_helpers.DisassemblyInstruction(addr, length, text)
yield InsnHandle(address=AbsoluteVirtualAddress(addr), inner=insn)
addr += length
def extract_insn_features(self, fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle):
yield from capa.features.extractors.binja.insn.extract_features(fh, bbh, ih)

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@@ -1,187 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import struct
from typing import Tuple, Iterator
from binaryninja import Segment, BinaryView, SymbolType, SymbolBinding
import capa.features.extractors.common
import capa.features.extractors.helpers
import capa.features.extractors.strings
from capa.features.file import Export, Import, Section, FunctionName
from capa.features.common import FORMAT_PE, FORMAT_ELF, Format, String, Feature, Characteristic
from capa.features.address import NO_ADDRESS, Address, FileOffsetAddress, AbsoluteVirtualAddress
from capa.features.extractors.binja.helpers import read_c_string, unmangle_c_name
def check_segment_for_pe(bv: BinaryView, seg: Segment) -> Iterator[Tuple[int, int]]:
"""check segment for embedded PE
adapted for binja from:
https://github.com/vivisect/vivisect/blob/7be4037b1cecc4551b397f840405a1fc606f9b53/PE/carve.py#L19
"""
mz_xor = [
(
capa.features.extractors.helpers.xor_static(b"MZ", i),
capa.features.extractors.helpers.xor_static(b"PE", i),
i,
)
for i in range(256)
]
todo = []
# If this is the first segment of the binary, skip the first bytes. Otherwise, there will always be a matched
# PE at the start of the binaryview.
start = seg.start
if bv.view_type == "PE" and start == bv.start:
start += 1
for mzx, pex, i in mz_xor:
for off, _ in bv.find_all_data(start, seg.end, mzx):
todo.append((off, mzx, pex, i))
while len(todo):
off, mzx, pex, i = todo.pop()
# The MZ header has one field we will check e_lfanew is at 0x3c
e_lfanew = off + 0x3C
if seg.end < (e_lfanew + 4):
continue
newoff = struct.unpack("<I", capa.features.extractors.helpers.xor_static(bv.read(e_lfanew, 4), i))[0]
peoff = off + newoff
if seg.end < (peoff + 2):
continue
if bv.read(peoff, 2) == pex:
yield off, i
def extract_file_embedded_pe(bv: BinaryView) -> Iterator[Tuple[Feature, Address]]:
"""extract embedded PE features"""
for seg in bv.segments:
for ea, _ in check_segment_for_pe(bv, seg):
yield Characteristic("embedded pe"), FileOffsetAddress(ea)
def extract_file_export_names(bv: BinaryView) -> Iterator[Tuple[Feature, Address]]:
"""extract function exports"""
for sym in bv.get_symbols_of_type(SymbolType.FunctionSymbol):
if sym.binding in [SymbolBinding.GlobalBinding, SymbolBinding.WeakBinding]:
name = sym.short_name
yield Export(name), AbsoluteVirtualAddress(sym.address)
unmangled_name = unmangle_c_name(name)
if name != unmangled_name:
yield Export(unmangled_name), AbsoluteVirtualAddress(sym.address)
for sym in bv.get_symbols_of_type(SymbolType.DataSymbol):
if sym.binding not in [SymbolBinding.GlobalBinding]:
continue
name = sym.short_name
if not name.startswith("__forwarder_name"):
continue
# Due to https://github.com/Vector35/binaryninja-api/issues/4641, in binja version 3.5, the symbol's name
# does not contain the DLL name. As a workaround, we read the C string at the symbol's address, which contains
# both the DLL name and the function name.
# Once the above issue is closed in the next binjs stable release, we can update the code here to use the
# symbol name directly.
name = read_c_string(bv, sym.address, 1024)
forwarded_name = capa.features.extractors.helpers.reformat_forwarded_export_name(name)
yield Export(forwarded_name), AbsoluteVirtualAddress(sym.address)
yield Characteristic("forwarded export"), AbsoluteVirtualAddress(sym.address)
def extract_file_import_names(bv: BinaryView) -> Iterator[Tuple[Feature, Address]]:
"""extract function imports
1. imports by ordinal:
- modulename.#ordinal
2. imports by name, results in two features to support importname-only
matching:
- modulename.importname
- importname
"""
for sym in bv.get_symbols_of_type(SymbolType.ImportAddressSymbol):
lib_name = str(sym.namespace)
addr = AbsoluteVirtualAddress(sym.address)
for name in capa.features.extractors.helpers.generate_symbols(lib_name, sym.short_name, include_dll=True):
yield Import(name), addr
ordinal = sym.ordinal
if ordinal != 0 and (lib_name != ""):
ordinal_name = f"#{ordinal}"
for name in capa.features.extractors.helpers.generate_symbols(lib_name, ordinal_name, include_dll=True):
yield Import(name), addr
def extract_file_section_names(bv: BinaryView) -> Iterator[Tuple[Feature, Address]]:
"""extract section names"""
for name, section in bv.sections.items():
yield Section(name), AbsoluteVirtualAddress(section.start)
def extract_file_strings(bv: BinaryView) -> Iterator[Tuple[Feature, Address]]:
"""extract ASCII and UTF-16 LE strings"""
for s in bv.strings:
yield String(s.value), FileOffsetAddress(s.start)
def extract_file_function_names(bv: BinaryView) -> Iterator[Tuple[Feature, Address]]:
"""
extract the names of statically-linked library functions.
"""
for sym_name in bv.symbols:
for sym in bv.symbols[sym_name]:
if sym.type not in [SymbolType.LibraryFunctionSymbol, SymbolType.FunctionSymbol]:
continue
name = sym.short_name
yield FunctionName(name), sym.address
if name.startswith("_"):
# some linkers may prefix linked routines with a `_` to avoid name collisions.
# extract features for both the mangled and un-mangled representations.
# e.g. `_fwrite` -> `fwrite`
# see: https://stackoverflow.com/a/2628384/87207
yield FunctionName(name[1:]), sym.address
def extract_file_format(bv: BinaryView) -> Iterator[Tuple[Feature, Address]]:
view_type = bv.view_type
if view_type in ["PE", "COFF"]:
yield Format(FORMAT_PE), NO_ADDRESS
elif view_type == "ELF":
yield Format(FORMAT_ELF), NO_ADDRESS
elif view_type == "Raw":
# no file type to return when processing a binary file, but we want to continue processing
return
else:
raise NotImplementedError(f"unexpected file format: {view_type}")
def extract_features(bv: BinaryView) -> Iterator[Tuple[Feature, Address]]:
"""extract file features"""
for file_handler in FILE_HANDLERS:
for feature, addr in file_handler(bv):
yield feature, addr
FILE_HANDLERS = (
extract_file_export_names,
extract_file_import_names,
extract_file_strings,
extract_file_section_names,
extract_file_embedded_pe,
extract_file_function_names,
extract_file_format,
)

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@@ -1,35 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import subprocess
from pathlib import Path
# When the script gets executed as a standalone executable (via PyInstaller), `import binaryninja` does not work because
# we have excluded the binaryninja module in `pyinstaller.spec`. The trick here is to call the system Python and try
# to find out the path of the binaryninja module that has been installed.
# Note, including the binaryninja module in the `pyintaller.spec` would not work, since the binaryninja module tries to
# find the binaryninja core e.g., `libbinaryninjacore.dylib`, using a relative path. And this does not work when the
# binaryninja module is extracted by the PyInstaller.
code = r"""
from pathlib import Path
from importlib import util
spec = util.find_spec('binaryninja')
if spec is not None:
if len(spec.submodule_search_locations) > 0:
path = Path(spec.submodule_search_locations[0])
# encode the path with utf8 then convert to hex, make sure it can be read and restored properly
print(str(path.parent).encode('utf8').hex())
"""
def find_binja_path() -> Path:
raw_output = subprocess.check_output(["python", "-c", code]).decode("ascii").strip()
return Path(bytes.fromhex(raw_output).decode("utf8"))
if __name__ == "__main__":
print(find_binja_path())

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@@ -1,104 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import Tuple, Iterator
from binaryninja import Function, BinaryView, SymbolType, RegisterValueType, LowLevelILOperation
from capa.features.file import FunctionName
from capa.features.common import Feature, Characteristic
from capa.features.address import Address, AbsoluteVirtualAddress
from capa.features.extractors import loops
from capa.features.extractors.base_extractor import FunctionHandle
def extract_function_calls_to(fh: FunctionHandle):
"""extract callers to a function"""
func: Function = fh.inner
for caller in func.caller_sites:
# Everything that is a code reference to the current function is considered a caller, which actually includes
# many other references that are NOT a caller. For example, an instruction `push function_start` will also be
# considered a caller to the function
llil = caller.llil
if (llil is None) or llil.operation not in [
LowLevelILOperation.LLIL_CALL,
LowLevelILOperation.LLIL_CALL_STACK_ADJUST,
LowLevelILOperation.LLIL_JUMP,
LowLevelILOperation.LLIL_TAILCALL,
]:
continue
if llil.dest.value.type not in [
RegisterValueType.ImportedAddressValue,
RegisterValueType.ConstantValue,
RegisterValueType.ConstantPointerValue,
]:
continue
address = llil.dest.value.value
if address != func.start:
continue
yield Characteristic("calls to"), AbsoluteVirtualAddress(caller.address)
def extract_function_loop(fh: FunctionHandle):
"""extract loop indicators from a function"""
func: Function = fh.inner
edges = []
# construct control flow graph
for bb in func.basic_blocks:
for edge in bb.outgoing_edges:
edges.append((bb.start, edge.target.start))
if loops.has_loop(edges):
yield Characteristic("loop"), fh.address
def extract_recursive_call(fh: FunctionHandle):
"""extract recursive function call"""
func: Function = fh.inner
bv: BinaryView = func.view
if bv is None:
return
for ref in bv.get_code_refs(func.start):
if ref.function == func:
yield Characteristic("recursive call"), fh.address
def extract_function_name(fh: FunctionHandle):
"""extract function names (e.g., symtab names)"""
func: Function = fh.inner
bv: BinaryView = func.view
if bv is None:
return
for sym in bv.get_symbols(func.start):
if sym.type not in [SymbolType.LibraryFunctionSymbol, SymbolType.FunctionSymbol]:
continue
name = sym.short_name
yield FunctionName(name), sym.address
if name.startswith("_"):
# some linkers may prefix linked routines with a `_` to avoid name collisions.
# extract features for both the mangled and un-mangled representations.
# e.g. `_fwrite` -> `fwrite`
# see: https://stackoverflow.com/a/2628384/87207
yield FunctionName(name[1:]), sym.address
def extract_features(fh: FunctionHandle) -> Iterator[Tuple[Feature, Address]]:
for func_handler in FUNCTION_HANDLERS:
for feature, addr in func_handler(fh):
yield feature, addr
FUNCTION_HANDLERS = (extract_function_calls_to, extract_function_loop, extract_recursive_call, extract_function_name)

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@@ -1,60 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
from typing import Tuple, Iterator
from binaryninja import BinaryView
from capa.features.common import OS, OS_MACOS, ARCH_I386, ARCH_AMD64, OS_WINDOWS, Arch, Feature
from capa.features.address import NO_ADDRESS, Address
logger = logging.getLogger(__name__)
def extract_os(bv: BinaryView) -> Iterator[Tuple[Feature, Address]]:
name = bv.platform.name
if "-" in name:
name = name.split("-")[0]
if name == "windows":
yield OS(OS_WINDOWS), NO_ADDRESS
elif name == "macos":
yield OS(OS_MACOS), NO_ADDRESS
elif name in ["linux", "freebsd", "decree"]:
yield OS(name), NO_ADDRESS
else:
# we likely end up here:
# 1. handling shellcode, or
# 2. handling a new file format (e.g. macho)
#
# for (1) we can't do much - its shellcode and all bets are off.
# we could maybe accept a further CLI argument to specify the OS,
# but i think this would be rarely used.
# rules that rely on OS conditions will fail to match on shellcode.
#
# for (2), this logic will need to be updated as the format is implemented.
logger.debug("unsupported file format: %s, will not guess OS", name)
return
def extract_arch(bv: BinaryView) -> Iterator[Tuple[Feature, Address]]:
arch = bv.arch.name
if arch == "x86_64":
yield Arch(ARCH_AMD64), NO_ADDRESS
elif arch == "x86":
yield Arch(ARCH_I386), NO_ADDRESS
else:
# we likely end up here:
# 1. handling a new architecture (e.g. aarch64)
#
# for (1), this logic will need to be updated as the format is implemented.
logger.debug("unsupported architecture: %s", arch)
return

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@@ -1,69 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import re
from typing import List, Callable
from dataclasses import dataclass
from binaryninja import BinaryView, LowLevelILInstruction
from binaryninja.architecture import InstructionTextToken
@dataclass
class DisassemblyInstruction:
address: int
length: int
text: List[InstructionTextToken]
LLIL_VISITOR = Callable[[LowLevelILInstruction, LowLevelILInstruction, int], bool]
def visit_llil_exprs(il: LowLevelILInstruction, func: LLIL_VISITOR):
# BN does not really support operand index at the disassembly level, so use the LLIL operand index as a substitute.
# Note, this is NOT always guaranteed to be the same as disassembly operand.
for i, op in enumerate(il.operands):
if isinstance(op, LowLevelILInstruction) and func(op, il, i):
visit_llil_exprs(op, func)
def unmangle_c_name(name: str) -> str:
# https://learn.microsoft.com/en-us/cpp/build/reference/decorated-names?view=msvc-170#FormatC
# Possible variations for BaseThreadInitThunk:
# @BaseThreadInitThunk@12
# _BaseThreadInitThunk
# _BaseThreadInitThunk@12
# It is also possible for a function to have a `Stub` appended to its name:
# _lstrlenWStub@4
# A small optimization to avoid running the regex too many times
# this still increases the unit test execution time from 170s to 200s, should be able to accelerate it
#
# TODO(xusheng): performance optimizations to improve test execution time
# https://github.com/mandiant/capa/issues/1610
if name[0] in ["@", "_"]:
match = re.match(r"^[@|_](.*?)(Stub)?(@\d+)?$", name)
if match:
return match.group(1)
return name
def read_c_string(bv: BinaryView, offset: int, max_len: int) -> str:
s: List[str] = []
while len(s) < max_len:
try:
c = bv.read(offset + len(s), 1)[0]
except Exception:
break
if c == 0:
break
s.append(chr(c))
return "".join(s)

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@@ -1,586 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import Any, List, Tuple, Iterator, Optional
from binaryninja import Function
from binaryninja import BasicBlock as BinjaBasicBlock
from binaryninja import (
BinaryView,
ILRegister,
SymbolType,
BinaryReader,
RegisterValueType,
LowLevelILOperation,
LowLevelILInstruction,
)
import capa.features.extractors.helpers
from capa.features.insn import API, MAX_STRUCTURE_SIZE, Number, Offset, Mnemonic, OperandNumber, OperandOffset
from capa.features.common import MAX_BYTES_FEATURE_SIZE, Bytes, String, Feature, Characteristic
from capa.features.address import Address, AbsoluteVirtualAddress
from capa.features.extractors.binja.helpers import DisassemblyInstruction, visit_llil_exprs
from capa.features.extractors.base_extractor import BBHandle, InsnHandle, FunctionHandle
# security cookie checks may perform non-zeroing XORs, these are expected within a certain
# byte range within the first and returning basic blocks, this helps to reduce FP features
SECURITY_COOKIE_BYTES_DELTA = 0x40
# check if a function is a stub function to another function/symbol. The criteria is:
# 1. The function must only have one basic block
# 2. The function must only make one call/jump to another address
# If the function being checked is a stub function, returns the target address. Otherwise, return None.
def is_stub_function(bv: BinaryView, addr: int) -> Optional[int]:
funcs = bv.get_functions_at(addr)
for func in funcs:
if len(func.basic_blocks) != 1:
continue
call_count = 0
call_target = None
for il in func.llil.instructions:
if il.operation in [
LowLevelILOperation.LLIL_CALL,
LowLevelILOperation.LLIL_CALL_STACK_ADJUST,
LowLevelILOperation.LLIL_JUMP,
LowLevelILOperation.LLIL_TAILCALL,
]:
call_count += 1
if il.dest.value.type in [
RegisterValueType.ImportedAddressValue,
RegisterValueType.ConstantValue,
RegisterValueType.ConstantPointerValue,
]:
call_target = il.dest.value.value
if call_count == 1 and call_target is not None:
return call_target
return None
def extract_insn_api_features(fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction API features
example:
call dword [0x00473038]
"""
func: Function = fh.inner
bv: BinaryView = func.view
for llil in func.get_llils_at(ih.address):
if llil.operation in [
LowLevelILOperation.LLIL_CALL,
LowLevelILOperation.LLIL_CALL_STACK_ADJUST,
LowLevelILOperation.LLIL_JUMP,
LowLevelILOperation.LLIL_TAILCALL,
]:
if llil.dest.value.type not in [
RegisterValueType.ImportedAddressValue,
RegisterValueType.ConstantValue,
RegisterValueType.ConstantPointerValue,
]:
continue
address = llil.dest.value.value
candidate_addrs = [address]
stub_addr = is_stub_function(bv, address)
if stub_addr is not None:
candidate_addrs.append(stub_addr)
for address in candidate_addrs:
for sym in func.view.get_symbols(address):
if sym is None or sym.type not in [
SymbolType.ImportAddressSymbol,
SymbolType.ImportedFunctionSymbol,
SymbolType.FunctionSymbol,
]:
continue
sym_name = sym.short_name
lib_name = ""
import_lib = bv.lookup_imported_object_library(sym.address)
if import_lib is not None:
lib_name = import_lib[0].name
if lib_name.endswith(".dll"):
lib_name = lib_name[:-4]
elif lib_name.endswith(".so"):
lib_name = lib_name[:-3]
for name in capa.features.extractors.helpers.generate_symbols(lib_name, sym_name):
yield API(name), ih.address
if sym_name.startswith("_"):
for name in capa.features.extractors.helpers.generate_symbols(lib_name, sym_name[1:]):
yield API(name), ih.address
def extract_insn_number_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction number features
example:
push 3136B0h ; dwControlCode
"""
func: Function = fh.inner
results: List[Tuple[Any[Number, OperandNumber], Address]] = []
def llil_checker(il: LowLevelILInstruction, parent: LowLevelILInstruction, index: int) -> bool:
if il.operation == LowLevelILOperation.LLIL_LOAD:
return False
if il.operation not in [LowLevelILOperation.LLIL_CONST, LowLevelILOperation.LLIL_CONST_PTR]:
return True
for op in parent.operands:
if isinstance(op, ILRegister) and op.name in ["esp", "ebp", "rsp", "rbp", "sp"]:
return False
elif isinstance(op, LowLevelILInstruction) and op.operation == LowLevelILOperation.LLIL_REG:
if op.src.name in ["esp", "ebp", "rsp", "rbp", "sp"]:
return False
raw_value = il.value.value
if parent.operation == LowLevelILOperation.LLIL_SUB:
raw_value = -raw_value
results.append((Number(raw_value), ih.address))
results.append((OperandNumber(index, raw_value), ih.address))
return False
for llil in func.get_llils_at(ih.address):
visit_llil_exprs(llil, llil_checker)
yield from results
def extract_insn_bytes_features(fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""
parse referenced byte sequences
example:
push offset iid_004118d4_IShellLinkA ; riid
"""
func: Function = fh.inner
bv: BinaryView = func.view
candidate_addrs = set()
llil = func.get_llil_at(ih.address)
if llil is None or llil.operation in [LowLevelILOperation.LLIL_CALL, LowLevelILOperation.LLIL_CALL_STACK_ADJUST]:
return
for ref in bv.get_code_refs_from(ih.address):
if ref == ih.address:
continue
if len(bv.get_functions_containing(ref)) > 0:
continue
candidate_addrs.add(ref)
# collect candidate address by enumerating all integers, https://github.com/Vector35/binaryninja-api/issues/3966
def llil_checker(il: LowLevelILInstruction, parent: LowLevelILInstruction, index: int) -> bool:
if il.operation in [LowLevelILOperation.LLIL_CONST, LowLevelILOperation.LLIL_CONST_PTR]:
value = il.value.value
if value > 0:
candidate_addrs.add(value)
return False
return True
for llil in func.get_llils_at(ih.address):
visit_llil_exprs(llil, llil_checker)
for addr in candidate_addrs:
extracted_bytes = bv.read(addr, MAX_BYTES_FEATURE_SIZE)
if extracted_bytes and not capa.features.extractors.helpers.all_zeros(extracted_bytes):
if bv.get_string_at(addr) is None:
# don't extract byte features for obvious strings
yield Bytes(extracted_bytes), ih.address
def extract_insn_string_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction string features
example:
push offset aAcr ; "ACR > "
"""
func: Function = fh.inner
bv: BinaryView = func.view
candidate_addrs = set()
# collect candidate address from code refs directly
for ref in bv.get_code_refs_from(ih.address):
if ref == ih.address:
continue
if len(bv.get_functions_containing(ref)) > 0:
continue
candidate_addrs.add(ref)
# collect candidate address by enumerating all integers, https://github.com/Vector35/binaryninja-api/issues/3966
def llil_checker(il: LowLevelILInstruction, parent: LowLevelILInstruction, index: int) -> bool:
if il.operation in [LowLevelILOperation.LLIL_CONST, LowLevelILOperation.LLIL_CONST_PTR]:
value = il.value.value
if value > 0:
candidate_addrs.add(value)
return False
return True
for llil in func.get_llils_at(ih.address):
visit_llil_exprs(llil, llil_checker)
# Now we have all the candidate address, check them for string or pointer to string
br = BinaryReader(bv)
for addr in candidate_addrs:
found = bv.get_string_at(addr)
if found:
yield String(found.value), ih.address
br.seek(addr)
pointer = None
if bv.arch.address_size == 4:
pointer = br.read32()
elif bv.arch.address_size == 8:
pointer = br.read64()
if pointer is not None:
found = bv.get_string_at(pointer)
if found:
yield String(found.value), ih.address
def extract_insn_offset_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction structure offset features
example:
.text:0040112F cmp [esi+4], ebx
"""
func: Function = fh.inner
results: List[Tuple[Any[Offset, OperandOffset], Address]] = []
address_size = func.view.arch.address_size * 8
def llil_checker(il: LowLevelILInstruction, parent: LowLevelILInstruction, index: int) -> bool:
# The most common case, read/write dereference to something like `dword [eax+0x28]`
if il.operation in [LowLevelILOperation.LLIL_ADD, LowLevelILOperation.LLIL_SUB]:
left = il.left
right = il.right
# Exclude offsets based on stack/franme pointers
if left.operation == LowLevelILOperation.LLIL_REG and left.src.name in ["esp", "ebp", "rsp", "rbp", "sp"]:
return True
if right.operation != LowLevelILOperation.LLIL_CONST:
return True
raw_value = right.value.value
# If this is not a dereference, then this must be an add and the offset must be in the range \
# [0, MAX_STRUCTURE_SIZE]. For example,
# add eax, 0x10,
# lea ebx, [eax + 1]
if parent.operation not in [LowLevelILOperation.LLIL_LOAD, LowLevelILOperation.LLIL_STORE]:
if il.operation != LowLevelILOperation.LLIL_ADD or (not 0 < raw_value < MAX_STRUCTURE_SIZE):
return False
if address_size > 0:
# BN also encodes the constant value as two's complement, we need to restore its original value
value = capa.features.extractors.helpers.twos_complement(raw_value, address_size)
else:
value = raw_value
results.append((Offset(value), ih.address))
results.append((OperandOffset(index, value), ih.address))
return False
# An edge case: for code like `push dword [esi]`, we need to generate a feature for offset 0x0
elif il.operation in [LowLevelILOperation.LLIL_LOAD, LowLevelILOperation.LLIL_STORE]:
if il.operands[0].operation == LowLevelILOperation.LLIL_REG:
results.append((Offset(0), ih.address))
results.append((OperandOffset(index, 0), ih.address))
return False
return True
for llil in func.get_llils_at(ih.address):
visit_llil_exprs(llil, llil_checker)
yield from results
def is_nzxor_stack_cookie(f: Function, bb: BinjaBasicBlock, llil: LowLevelILInstruction) -> bool:
"""check if nzxor exists within stack cookie delta"""
# TODO(xusheng): use LLIL SSA to do more accurate analysis
# https://github.com/mandiant/capa/issues/1609
reg_names = []
if llil.left.operation == LowLevelILOperation.LLIL_REG:
reg_names.append(llil.left.src.name)
if llil.right.operation == LowLevelILOperation.LLIL_REG:
reg_names.append(llil.right.src.name)
# stack cookie reg should be stack/frame pointer
if not any(reg in ["ebp", "esp", "rbp", "rsp", "sp"] for reg in reg_names):
return False
# expect security cookie init in first basic block within first bytes (instructions)
if len(bb.incoming_edges) == 0 and llil.address < (bb.start + SECURITY_COOKIE_BYTES_DELTA):
return True
# ... or within last bytes (instructions) before a return
if len(bb.outgoing_edges) == 0 and llil.address > (bb.end - SECURITY_COOKIE_BYTES_DELTA):
return True
return False
def extract_insn_nzxor_characteristic_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction non-zeroing XOR instruction
ignore expected non-zeroing XORs, e.g. security cookies
"""
func: Function = fh.inner
results = []
def llil_checker(il: LowLevelILInstruction, parent: LowLevelILInstruction, index: int) -> bool:
# If the two operands of the xor instruction are the same, the LLIL will be translated to other instructions,
# e.g., <llil: eax = 0>, (LLIL_SET_REG). So we do not need to check whether the two operands are the same.
if il.operation == LowLevelILOperation.LLIL_XOR:
# Exclude cases related to the stack cookie
if is_nzxor_stack_cookie(fh.inner, bbh.inner[0], il):
return False
results.append((Characteristic("nzxor"), ih.address))
return False
else:
return True
for llil in func.get_llils_at(ih.address):
visit_llil_exprs(llil, llil_checker)
yield from results
def extract_insn_mnemonic_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""parse instruction mnemonic features"""
insn: DisassemblyInstruction = ih.inner
yield Mnemonic(insn.text[0].text), ih.address
def extract_insn_obfs_call_plus_5_characteristic_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""
parse call $+5 instruction from the given instruction.
"""
insn: DisassemblyInstruction = ih.inner
if insn.text[0].text == "call" and insn.text[2].text == "$+5" and insn.length == 5:
yield Characteristic("call $+5"), ih.address
def extract_insn_peb_access_characteristic_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""parse instruction peb access
fs:[0x30] on x86, gs:[0x60] on x64
"""
func: Function = fh.inner
results = []
def llil_checker(il: LowLevelILInstruction, parent: LowLevelILOperation, index: int) -> bool:
if il.operation != LowLevelILOperation.LLIL_LOAD:
return True
src = il.src
if src.operation != LowLevelILOperation.LLIL_ADD:
return True
left = src.left
right = src.right
if left.operation != LowLevelILOperation.LLIL_REG:
return True
reg = left.src.name
if right.operation != LowLevelILOperation.LLIL_CONST:
return True
value = right.value.value
if (reg, value) not in (("fsbase", 0x30), ("gsbase", 0x60)):
return True
results.append((Characteristic("peb access"), ih.address))
return False
for llil in func.get_llils_at(ih.address):
visit_llil_exprs(llil, llil_checker)
yield from results
def extract_insn_segment_access_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""parse instruction fs or gs access"""
func: Function = fh.inner
results = []
def llil_checker(il: LowLevelILInstruction, parent: LowLevelILInstruction, index: int) -> bool:
if il.operation == LowLevelILOperation.LLIL_REG:
reg = il.src.name
if reg == "fsbase":
results.append((Characteristic("fs access"), ih.address))
return False
elif reg == "gsbase":
results.append((Characteristic("gs access"), ih.address))
return False
return False
return True
for llil in func.get_llils_at(ih.address):
visit_llil_exprs(llil, llil_checker)
yield from results
def extract_insn_cross_section_cflow(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""inspect the instruction for a CALL or JMP that crosses section boundaries"""
func: Function = fh.inner
bv: BinaryView = func.view
if bv is None:
return
seg1 = bv.get_segment_at(ih.address)
sections1 = bv.get_sections_at(ih.address)
for ref in bv.get_code_refs_from(ih.address):
if len(bv.get_functions_at(ref)) == 0:
continue
seg2 = bv.get_segment_at(ref)
sections2 = bv.get_sections_at(ref)
if seg1 != seg2 or sections1 != sections2:
yield Characteristic("cross section flow"), ih.address
def extract_function_calls_from(fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""extract functions calls from features
most relevant at the function scope, however, its most efficient to extract at the instruction scope
"""
func: Function = fh.inner
bv: BinaryView = func.view
if bv is None:
return
for il in func.get_llils_at(ih.address):
if il.operation not in [
LowLevelILOperation.LLIL_CALL,
LowLevelILOperation.LLIL_CALL_STACK_ADJUST,
LowLevelILOperation.LLIL_TAILCALL,
]:
continue
dest = il.dest
if dest.operation == LowLevelILOperation.LLIL_CONST_PTR:
value = dest.value.value
yield Characteristic("calls from"), AbsoluteVirtualAddress(value)
elif dest.operation == LowLevelILOperation.LLIL_CONST:
yield Characteristic("calls from"), AbsoluteVirtualAddress(dest.value)
elif dest.operation == LowLevelILOperation.LLIL_LOAD:
indirect_src = dest.src
if indirect_src.operation == LowLevelILOperation.LLIL_CONST_PTR:
value = indirect_src.value.value
yield Characteristic("calls from"), AbsoluteVirtualAddress(value)
elif indirect_src.operation == LowLevelILOperation.LLIL_CONST:
yield Characteristic("calls from"), AbsoluteVirtualAddress(indirect_src.value)
elif dest.operation == LowLevelILOperation.LLIL_REG:
if dest.value.type in [
RegisterValueType.ImportedAddressValue,
RegisterValueType.ConstantValue,
RegisterValueType.ConstantPointerValue,
]:
yield Characteristic("calls from"), AbsoluteVirtualAddress(dest.value.value)
def extract_function_indirect_call_characteristic_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""extract indirect function calls (e.g., call eax or call dword ptr [edx+4])
does not include calls like => call ds:dword_ABD4974
most relevant at the function or basic block scope;
however, its most efficient to extract at the instruction scope
"""
func: Function = fh.inner
llil = func.get_llil_at(ih.address)
if llil is None or llil.operation not in [
LowLevelILOperation.LLIL_CALL,
LowLevelILOperation.LLIL_CALL_STACK_ADJUST,
LowLevelILOperation.LLIL_TAILCALL,
]:
return
if llil.dest.operation in [LowLevelILOperation.LLIL_CONST, LowLevelILOperation.LLIL_CONST_PTR]:
return
if llil.dest.operation == LowLevelILOperation.LLIL_LOAD:
src = llil.dest.src
if src.operation in [LowLevelILOperation.LLIL_CONST, LowLevelILOperation.LLIL_CONST_PTR]:
return
yield Characteristic("indirect call"), ih.address
def extract_features(f: FunctionHandle, bbh: BBHandle, insn: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""extract instruction features"""
for inst_handler in INSTRUCTION_HANDLERS:
for feature, ea in inst_handler(f, bbh, insn):
yield feature, ea
INSTRUCTION_HANDLERS = (
extract_insn_api_features,
extract_insn_number_features,
extract_insn_bytes_features,
extract_insn_string_features,
extract_insn_offset_features,
extract_insn_nzxor_characteristic_features,
extract_insn_mnemonic_features,
extract_insn_obfs_call_plus_5_characteristic_features,
extract_insn_peb_access_characteristic_features,
extract_insn_cross_section_cflow,
extract_insn_segment_access_features,
extract_function_calls_from,
extract_function_indirect_call_characteristic_features,
)

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@@ -1,62 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
from typing import Tuple, Iterator
from capa.helpers import assert_never
from capa.features.insn import API, Number
from capa.features.common import String, Feature
from capa.features.address import Address
from capa.features.extractors.cape.models import Call
from capa.features.extractors.base_extractor import CallHandle, ThreadHandle, ProcessHandle
logger = logging.getLogger(__name__)
def extract_call_features(ph: ProcessHandle, th: ThreadHandle, ch: CallHandle) -> Iterator[Tuple[Feature, Address]]:
"""
this method extracts the given call's features (such as API name and arguments),
and returns them as API, Number, and String features.
args:
ph: process handle (for defining the extraction scope)
th: thread handle (for defining the extraction scope)
ch: call handle (for defining the extraction scope)
yields:
Feature, address; where Feature is either: API, Number, or String.
"""
call: Call = ch.inner
# list similar to disassembly: arguments right-to-left, call
for arg in reversed(call.arguments):
value = arg.value
if isinstance(value, list) and len(value) == 0:
# unsure why CAPE captures arguments as empty lists?
continue
elif isinstance(value, str):
yield String(value), ch.address
elif isinstance(value, int):
yield Number(value), ch.address
else:
assert_never(value)
yield API(call.api), ch.address
def extract_features(ph: ProcessHandle, th: ThreadHandle, ch: CallHandle) -> Iterator[Tuple[Feature, Address]]:
for handler in CALL_HANDLERS:
for feature, addr in handler(ph, th, ch):
yield feature, addr
CALL_HANDLERS = (extract_call_features,)

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@@ -1,153 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
from typing import Dict, Tuple, Union, Iterator
import capa.features.extractors.cape.call
import capa.features.extractors.cape.file
import capa.features.extractors.cape.thread
import capa.features.extractors.cape.global_
import capa.features.extractors.cape.process
from capa.exceptions import EmptyReportError, UnsupportedFormatError
from capa.features.common import Feature, Characteristic
from capa.features.address import NO_ADDRESS, Address, AbsoluteVirtualAddress, _NoAddress
from capa.features.extractors.cape.models import Call, Static, Process, CapeReport
from capa.features.extractors.base_extractor import (
CallHandle,
SampleHashes,
ThreadHandle,
ProcessHandle,
DynamicFeatureExtractor,
)
logger = logging.getLogger(__name__)
TESTED_VERSIONS = {"2.2-CAPE", "2.4-CAPE"}
class CapeExtractor(DynamicFeatureExtractor):
def __init__(self, report: CapeReport):
super().__init__(
hashes=SampleHashes(
md5=report.target.file.md5.lower(),
sha1=report.target.file.sha1.lower(),
sha256=report.target.file.sha256.lower(),
)
)
self.report: CapeReport = report
# pre-compute these because we'll yield them at *every* scope.
self.global_features = list(capa.features.extractors.cape.global_.extract_features(self.report))
def get_base_address(self) -> Union[AbsoluteVirtualAddress, _NoAddress, None]:
# value according to the PE header, the actual trace may use a different imagebase
assert self.report.static is not None and self.report.static.pe is not None
return AbsoluteVirtualAddress(self.report.static.pe.imagebase)
def extract_global_features(self) -> Iterator[Tuple[Feature, Address]]:
yield from self.global_features
def extract_file_features(self) -> Iterator[Tuple[Feature, Address]]:
yield from capa.features.extractors.cape.file.extract_features(self.report)
def get_processes(self) -> Iterator[ProcessHandle]:
yield from capa.features.extractors.cape.file.get_processes(self.report)
def extract_process_features(self, ph: ProcessHandle) -> Iterator[Tuple[Feature, Address]]:
yield from capa.features.extractors.cape.process.extract_features(ph)
def get_process_name(self, ph) -> str:
process: Process = ph.inner
return process.process_name
def get_threads(self, ph: ProcessHandle) -> Iterator[ThreadHandle]:
yield from capa.features.extractors.cape.process.get_threads(ph)
def extract_thread_features(self, ph: ProcessHandle, th: ThreadHandle) -> Iterator[Tuple[Feature, Address]]:
if False:
# force this routine to be a generator,
# but we don't actually have any elements to generate.
yield Characteristic("never"), NO_ADDRESS
return
def get_calls(self, ph: ProcessHandle, th: ThreadHandle) -> Iterator[CallHandle]:
yield from capa.features.extractors.cape.thread.get_calls(ph, th)
def extract_call_features(
self, ph: ProcessHandle, th: ThreadHandle, ch: CallHandle
) -> Iterator[Tuple[Feature, Address]]:
yield from capa.features.extractors.cape.call.extract_features(ph, th, ch)
def get_call_name(self, ph, th, ch) -> str:
call: Call = ch.inner
parts = []
parts.append(call.api)
parts.append("(")
for argument in call.arguments:
parts.append(argument.name)
parts.append("=")
if argument.pretty_value:
parts.append(argument.pretty_value)
else:
if isinstance(argument.value, int):
parts.append(hex(argument.value))
elif isinstance(argument.value, str):
parts.append('"')
parts.append(argument.value)
parts.append('"')
elif isinstance(argument.value, list):
pass
else:
capa.helpers.assert_never(argument.value)
parts.append(", ")
if call.arguments:
# remove the trailing comma
parts.pop()
parts.append(")")
parts.append(" -> ")
if call.pretty_return:
parts.append(call.pretty_return)
else:
parts.append(hex(call.return_))
return "".join(parts)
@classmethod
def from_report(cls, report: Dict) -> "CapeExtractor":
cr = CapeReport.model_validate(report)
if cr.info.version not in TESTED_VERSIONS:
logger.warning("CAPE version '%s' not tested/supported yet", cr.info.version)
# TODO(mr-tz): support more file types
# https://github.com/mandiant/capa/issues/1933
if "PE" not in cr.target.file.type:
logger.error(
"capa currently only supports PE target files, this target file's type is: '%s'.\nPlease report this at: https://github.com/mandiant/capa/issues/1933",
cr.target.file.type,
)
# observed in 2.4-CAPE reports from capesandbox.com
if cr.static is None and cr.target.file.pe is not None:
cr.static = Static()
cr.static.pe = cr.target.file.pe
if cr.static is None:
raise UnsupportedFormatError("CAPE report missing static analysis")
if cr.static.pe is None:
raise UnsupportedFormatError("CAPE report missing PE analysis")
if len(cr.behavior.processes) == 0:
raise EmptyReportError("CAPE did not capture any processes")
return cls(cr)

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@@ -1,132 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
from typing import Tuple, Iterator
from capa.features.file import Export, Import, Section
from capa.features.common import String, Feature
from capa.features.address import NO_ADDRESS, Address, ProcessAddress, AbsoluteVirtualAddress
from capa.features.extractors.helpers import generate_symbols
from capa.features.extractors.cape.models import CapeReport
from capa.features.extractors.base_extractor import ProcessHandle
logger = logging.getLogger(__name__)
def get_processes(report: CapeReport) -> Iterator[ProcessHandle]:
"""
get all the created processes for a sample
"""
seen_processes = {}
for process in report.behavior.processes:
addr = ProcessAddress(pid=process.process_id, ppid=process.parent_id)
yield ProcessHandle(address=addr, inner=process)
# check for pid and ppid reuse
if addr not in seen_processes:
seen_processes[addr] = [process]
else:
logger.warning(
"pid and ppid reuse detected between process %s and process%s: %s",
process,
"es" if len(seen_processes[addr]) > 1 else "",
seen_processes[addr],
)
seen_processes[addr].append(process)
def extract_import_names(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
"""
extract imported function names
"""
assert report.static is not None and report.static.pe is not None
imports = report.static.pe.imports
if isinstance(imports, dict):
imports = list(imports.values())
assert isinstance(imports, list)
for library in imports:
for function in library.imports:
if not function.name:
continue
for name in generate_symbols(library.dll, function.name, include_dll=True):
yield Import(name), AbsoluteVirtualAddress(function.address)
def extract_export_names(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
assert report.static is not None and report.static.pe is not None
for function in report.static.pe.exports:
yield Export(function.name), AbsoluteVirtualAddress(function.address)
def extract_section_names(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
assert report.static is not None and report.static.pe is not None
for section in report.static.pe.sections:
yield Section(section.name), AbsoluteVirtualAddress(section.virtual_address)
def extract_file_strings(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
if report.strings is not None:
for string in report.strings:
yield String(string), NO_ADDRESS
def extract_used_regkeys(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
for regkey in report.behavior.summary.keys:
yield String(regkey), NO_ADDRESS
def extract_used_files(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
for file in report.behavior.summary.files:
yield String(file), NO_ADDRESS
def extract_used_mutexes(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
for mutex in report.behavior.summary.mutexes:
yield String(mutex), NO_ADDRESS
def extract_used_commands(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
for cmd in report.behavior.summary.executed_commands:
yield String(cmd), NO_ADDRESS
def extract_used_apis(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
for symbol in report.behavior.summary.resolved_apis:
yield String(symbol), NO_ADDRESS
def extract_used_services(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
for svc in report.behavior.summary.created_services:
yield String(svc), NO_ADDRESS
for svc in report.behavior.summary.started_services:
yield String(svc), NO_ADDRESS
def extract_features(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
for handler in FILE_HANDLERS:
for feature, addr in handler(report):
yield feature, addr
FILE_HANDLERS = (
extract_import_names,
extract_export_names,
extract_section_names,
extract_file_strings,
extract_used_regkeys,
extract_used_files,
extract_used_mutexes,
extract_used_commands,
extract_used_apis,
extract_used_services,
)

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@@ -1,93 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
from typing import Tuple, Iterator
from capa.features.common import (
OS,
OS_ANY,
OS_LINUX,
ARCH_I386,
FORMAT_PE,
ARCH_AMD64,
FORMAT_ELF,
OS_WINDOWS,
Arch,
Format,
Feature,
)
from capa.features.address import NO_ADDRESS, Address
from capa.features.extractors.cape.models import CapeReport
logger = logging.getLogger(__name__)
def extract_arch(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
if "Intel 80386" in report.target.file.type:
yield Arch(ARCH_I386), NO_ADDRESS
elif "x86-64" in report.target.file.type:
yield Arch(ARCH_AMD64), NO_ADDRESS
else:
logger.warning("unrecognized Architecture: %s", report.target.file.type)
raise ValueError(
f"unrecognized Architecture from the CAPE report; output of file command: {report.target.file.type}"
)
def extract_format(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
if "PE" in report.target.file.type:
yield Format(FORMAT_PE), NO_ADDRESS
elif "ELF" in report.target.file.type:
yield Format(FORMAT_ELF), NO_ADDRESS
else:
logger.warning("unknown file format, file command output: %s", report.target.file.type)
raise ValueError(
"unrecognized file format from the CAPE report; output of file command: {report.target.file.type}"
)
def extract_os(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
# this variable contains the output of the file command
file_output = report.target.file.type
if "windows" in file_output.lower():
yield OS(OS_WINDOWS), NO_ADDRESS
elif "elf" in file_output.lower():
# operating systems recognized by the file command: https://github.com/file/file/blob/master/src/readelf.c#L609
if "Linux" in file_output:
yield OS(OS_LINUX), NO_ADDRESS
elif "Hurd" in file_output:
yield OS("hurd"), NO_ADDRESS
elif "Solaris" in file_output:
yield OS("solaris"), NO_ADDRESS
elif "kFreeBSD" in file_output:
yield OS("freebsd"), NO_ADDRESS
elif "kNetBSD" in file_output:
yield OS("netbsd"), NO_ADDRESS
else:
# if the operating system information is missing from the cape report, it's likely a bug
logger.warning("unrecognized OS: %s", file_output)
raise ValueError("unrecognized OS from the CAPE report; output of file command: {file_output}")
else:
# the sample is shellcode
logger.debug("unsupported file format, file command output: %s", file_output)
yield OS(OS_ANY), NO_ADDRESS
def extract_features(report: CapeReport) -> Iterator[Tuple[Feature, Address]]:
for global_handler in GLOBAL_HANDLER:
for feature, addr in global_handler(report):
yield feature, addr
GLOBAL_HANDLER = (
extract_format,
extract_os,
extract_arch,
)

View File

@@ -1,29 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import Any, Dict, List
from capa.features.extractors.base_extractor import ProcessHandle
def find_process(processes: List[Dict[str, Any]], ph: ProcessHandle) -> Dict[str, Any]:
"""
find a specific process identified by a process handler.
args:
processes: a list of processes extracted by CAPE
ph: handle of the sought process
return:
a CAPE-defined dictionary for the sought process' information
"""
for process in processes:
if ph.address.ppid == process["parent_id"] and ph.address.pid == process["process_id"]:
return process
return {}

View File

@@ -1,446 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import binascii
from typing import Any, Dict, List, Union, Literal, Optional
from pydantic import Field, BaseModel, ConfigDict
from typing_extensions import Annotated, TypeAlias
from pydantic.functional_validators import BeforeValidator
def validate_hex_int(value):
if isinstance(value, str):
return int(value, 16) if value.startswith("0x") else int(value, 10)
else:
return value
def validate_hex_bytes(value):
return binascii.unhexlify(value) if isinstance(value, str) else value
HexInt = Annotated[int, BeforeValidator(validate_hex_int)]
HexBytes = Annotated[bytes, BeforeValidator(validate_hex_bytes)]
# a model that *cannot* have extra fields
# if they do, pydantic raises an exception.
# use this for models we rely upon and cannot change.
#
# for things that may be extended and we don't care,
# use FlexibleModel.
class ExactModel(BaseModel):
model_config = ConfigDict(extra="forbid")
# a model that can have extra fields that we ignore.
# use this if we don't want to raise an exception for extra
# data fields that we didn't expect.
class FlexibleModel(BaseModel):
pass
# use this type to indicate that we won't model this data.
# because its not relevant to our use in capa.
#
# while its nice to have full coverage of the data shape,
# it can easily change and break our parsing.
# so we really only want to describe what we'll use.
Skip: TypeAlias = Optional[Any]
# mark fields that we haven't seen yet and need to model.
# pydantic should raise an error when encountering data
# in a field with this type.
# then we can update the model with the discovered shape.
TODO: TypeAlias = None
ListTODO: TypeAlias = List[None]
DictTODO: TypeAlias = ExactModel
EmptyDict: TypeAlias = BaseModel
EmptyList: TypeAlias = List[Any]
class Info(FlexibleModel):
version: str
class ImportedSymbol(ExactModel):
address: HexInt
name: Optional[str] = None
class ImportedDll(ExactModel):
dll: str
imports: List[ImportedSymbol]
class DirectoryEntry(ExactModel):
name: str
virtual_address: HexInt
size: HexInt
class Section(ExactModel):
name: str
raw_address: HexInt
virtual_address: HexInt
virtual_size: HexInt
size_of_data: HexInt
characteristics: str
characteristics_raw: HexInt
entropy: float
class Resource(ExactModel):
name: str
language: Optional[str] = None
sublanguage: str
filetype: Optional[str]
offset: HexInt
size: HexInt
entropy: float
class DigitalSigner(FlexibleModel):
md5_fingerprint: str
not_after: str
not_before: str
serial_number: str
sha1_fingerprint: str
sha256_fingerprint: str
issuer_commonName: Optional[str] = None
issuer_countryName: Optional[str] = None
issuer_localityName: Optional[str] = None
issuer_organizationName: Optional[str] = None
issuer_stateOrProvinceName: Optional[str] = None
subject_commonName: Optional[str] = None
subject_countryName: Optional[str] = None
subject_localityName: Optional[str] = None
subject_organizationName: Optional[str] = None
subject_stateOrProvinceName: Optional[str] = None
extensions_authorityInfoAccess_caIssuers: Optional[str] = None
extensions_authorityKeyIdentifier: Optional[str] = None
extensions_cRLDistributionPoints_0: Optional[str] = None
extensions_certificatePolicies_0: Optional[str] = None
extensions_subjectAltName_0: Optional[str] = None
extensions_subjectKeyIdentifier: Optional[str] = None
class AuxSigner(ExactModel):
name: str
issued_to: str = Field(alias="Issued to")
issued_by: str = Field(alias="Issued by")
expires: str = Field(alias="Expires")
sha1_hash: str = Field(alias="SHA1 hash")
class Signer(ExactModel):
aux_sha1: Optional[str] = None
aux_timestamp: Optional[str] = None
aux_valid: Optional[bool] = None
aux_error: Optional[bool] = None
aux_error_desc: Optional[str] = None
aux_signers: Optional[List[AuxSigner]] = None
class Overlay(ExactModel):
offset: HexInt
size: HexInt
class KV(ExactModel):
name: str
value: str
class ExportedSymbol(ExactModel):
address: HexInt
name: str
ordinal: int
class PE(ExactModel):
peid_signatures: TODO
imagebase: HexInt
entrypoint: HexInt
reported_checksum: HexInt
actual_checksum: HexInt
osversion: str
pdbpath: Optional[str] = None
timestamp: str
# List[ImportedDll], or Dict[basename(dll), ImportedDll]
imports: Union[List[ImportedDll], Dict[str, ImportedDll]]
imported_dll_count: Optional[int] = None
imphash: str
exported_dll_name: Optional[str] = None
exports: List[ExportedSymbol]
dirents: List[DirectoryEntry]
sections: List[Section]
ep_bytes: Optional[HexBytes] = None
overlay: Optional[Overlay] = None
resources: List[Resource]
versioninfo: List[KV]
# base64 encoded data
icon: Optional[str] = None
# MD5-like hash
icon_hash: Optional[str] = None
# MD5-like hash
icon_fuzzy: Optional[str] = None
# short hex string
icon_dhash: Optional[str] = None
digital_signers: List[DigitalSigner]
guest_signers: Signer
# TODO(mr-tz): target.file.dotnet, target.file.extracted_files, target.file.extracted_files_tool,
# target.file.extracted_files_time
# https://github.com/mandiant/capa/issues/1814
class File(FlexibleModel):
type: str
cape_type_code: Optional[int] = None
cape_type: Optional[str] = None
pid: Optional[Union[int, Literal[""]]] = None
name: Union[List[str], str]
path: str
guest_paths: Union[List[str], str, None]
timestamp: Optional[str] = None
#
# hashes
#
crc32: str
md5: str
sha1: str
sha256: str
sha512: str
sha3_384: str
ssdeep: str
# unsure why this would ever be "False"
tlsh: Optional[Union[str, bool]] = None
rh_hash: Optional[str] = None
#
# other metadata, static analysis
#
size: int
pe: Optional[PE] = None
ep_bytes: Optional[HexBytes] = None
entrypoint: Optional[int] = None
data: Optional[str] = None
strings: Optional[List[str]] = None
#
# detections (skip)
#
yara: Skip = None
cape_yara: Skip = None
clamav: Skip = None
virustotal: Skip = None
class ProcessFile(File):
#
# like a File, but also has dynamic analysis results
#
pid: Optional[int] = None
process_path: Optional[str] = None
process_name: Optional[str] = None
module_path: Optional[str] = None
virtual_address: Optional[HexInt] = None
target_pid: Optional[Union[int, str]] = None
target_path: Optional[str] = None
target_process: Optional[str] = None
class Argument(ExactModel):
name: str
# unsure why empty list is provided here
value: Union[HexInt, int, str, EmptyList]
pretty_value: Optional[str] = None
class Call(ExactModel):
timestamp: str
thread_id: int
category: str
api: str
arguments: List[Argument]
status: bool
return_: HexInt = Field(alias="return")
pretty_return: Optional[str] = None
repeated: int
# virtual addresses
caller: HexInt
parentcaller: HexInt
# index into calls array
id: int
class Process(ExactModel):
process_id: int
process_name: str
parent_id: int
module_path: str
first_seen: str
calls: List[Call]
threads: List[int]
environ: Dict[str, str]
class ProcessTree(ExactModel):
name: str
pid: int
parent_id: int
module_path: str
threads: List[int]
environ: Dict[str, str]
children: List["ProcessTree"]
class Summary(ExactModel):
files: List[str]
read_files: List[str]
write_files: List[str]
delete_files: List[str]
keys: List[str]
read_keys: List[str]
write_keys: List[str]
delete_keys: List[str]
executed_commands: List[str]
resolved_apis: List[str]
mutexes: List[str]
created_services: List[str]
started_services: List[str]
class EncryptedBuffer(ExactModel):
process_name: str
pid: int
api_call: str
buffer: str
buffer_size: Optional[int] = None
crypt_key: Optional[Union[HexInt, str]] = None
class Behavior(ExactModel):
summary: Summary
# list of processes, of threads, of calls
processes: List[Process]
# tree of processes
processtree: List[ProcessTree]
anomaly: List[str]
encryptedbuffers: List[EncryptedBuffer]
# these are small objects that describe atomic events,
# like file move, registery access.
# we'll detect the same with our API call analyis.
enhanced: Skip = None
class Target(ExactModel):
category: str
file: File
pe: Optional[PE] = None
class Static(ExactModel):
pe: Optional[PE] = None
flare_capa: Skip = None
class Cape(ExactModel):
payloads: List[ProcessFile]
configs: Skip = None
# flexible because there may be more sorts of analysis
# but we only care about the ones described here.
class CapeReport(FlexibleModel):
# the input file, I think
target: Target
# info about the processing job, like machine and distributed metadata.
info: Info
#
# static analysis results
#
static: Optional[Static] = None
strings: Optional[List[str]] = None
#
# dynamic analysis results
#
# post-processed results: process tree, anomalies, etc
behavior: Behavior
# post-processed results: payloads and extracted configs
CAPE: Optional[Cape] = None
dropped: Optional[List[File]] = None
procdump: Optional[List[ProcessFile]] = None
procmemory: ListTODO
# =========================================================================
# information we won't use in capa
#
#
# NBIs and HBIs
# these are super interesting, but they don't enable use to detect behaviors.
# they take a lot of code to model and details to maintain.
#
# if we come up with a future use for this, go ahead and re-enable!
#
network: Skip = None
suricata: Skip = None
curtain: Skip = None
sysmon: Skip = None
url_analysis: Skip = None
# screenshot hash values
deduplicated_shots: Skip = None
# k-v pairs describing the time it took to run each stage.
statistics: Skip = None
# k-v pairs of ATT&CK ID to signature name or similar.
ttps: Skip = None
# debug log messages
debug: Skip = None
# various signature matches
# we could potentially extend capa to use this info one day,
# though it would be quite sandbox-specific,
# and more detection-oriented than capability detection.
signatures: Skip = None
malfamily_tag: Optional[str] = None
malscore: float
detections: Skip = None
detections2pid: Optional[Dict[int, List[str]]] = None
# AV detections for the sample.
virustotal: Skip = None
@classmethod
def from_buf(cls, buf: bytes) -> "CapeReport":
return cls.model_validate_json(buf)

View File

@@ -1,48 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
from typing import List, Tuple, Iterator
from capa.features.common import String, Feature
from capa.features.address import Address, ThreadAddress
from capa.features.extractors.cape.models import Process
from capa.features.extractors.base_extractor import ThreadHandle, ProcessHandle
logger = logging.getLogger(__name__)
def get_threads(ph: ProcessHandle) -> Iterator[ThreadHandle]:
"""
get the threads associated with a given process
"""
process: Process = ph.inner
threads: List[int] = process.threads
for thread in threads:
address: ThreadAddress = ThreadAddress(process=ph.address, tid=thread)
yield ThreadHandle(address=address, inner={})
def extract_environ_strings(ph: ProcessHandle) -> Iterator[Tuple[Feature, Address]]:
"""
extract strings from a process' provided environment variables.
"""
process: Process = ph.inner
for value in (value for value in process.environ.values() if value):
yield String(value), ph.address
def extract_features(ph: ProcessHandle) -> Iterator[Tuple[Feature, Address]]:
for handler in PROCESS_HANDLERS:
for feature, addr in handler(ph):
yield feature, addr
PROCESS_HANDLERS = (extract_environ_strings,)

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@@ -1,32 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
from typing import Iterator
from capa.features.address import DynamicCallAddress
from capa.features.extractors.helpers import generate_symbols
from capa.features.extractors.cape.models import Process
from capa.features.extractors.base_extractor import CallHandle, ThreadHandle, ProcessHandle
logger = logging.getLogger(__name__)
def get_calls(ph: ProcessHandle, th: ThreadHandle) -> Iterator[CallHandle]:
process: Process = ph.inner
tid = th.address.tid
for call_index, call in enumerate(process.calls):
if call.thread_id != tid:
continue
for symbol in generate_symbols("", call.api):
call.api = symbol
addr = DynamicCallAddress(thread=th.address, id=call_index)
yield CallHandle(address=addr, inner=call)

View File

@@ -1,142 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import io
import re
import logging
import binascii
import contextlib
from typing import Tuple, Iterator
import pefile
import capa.features
import capa.features.extractors.elf
import capa.features.extractors.pefile
import capa.features.extractors.strings
from capa.features.common import (
OS,
OS_ANY,
OS_AUTO,
ARCH_ANY,
FORMAT_PE,
FORMAT_ELF,
OS_WINDOWS,
FORMAT_FREEZE,
FORMAT_RESULT,
Arch,
Format,
String,
Feature,
)
from capa.features.freeze import is_freeze
from capa.features.address import NO_ADDRESS, Address, FileOffsetAddress
logger = logging.getLogger(__name__)
# match strings for formats
MATCH_PE = b"MZ"
MATCH_ELF = b"\x7fELF"
MATCH_RESULT = b'{"meta":'
MATCH_JSON_OBJECT = b'{"'
def extract_file_strings(buf: bytes, **kwargs) -> Iterator[Tuple[String, Address]]:
"""
extract ASCII and UTF-16 LE strings from file
"""
for s in capa.features.extractors.strings.extract_ascii_strings(buf):
yield String(s.s), FileOffsetAddress(s.offset)
for s in capa.features.extractors.strings.extract_unicode_strings(buf):
yield String(s.s), FileOffsetAddress(s.offset)
def extract_format(buf: bytes) -> Iterator[Tuple[Feature, Address]]:
if buf.startswith(MATCH_PE):
yield Format(FORMAT_PE), NO_ADDRESS
elif buf.startswith(MATCH_ELF):
yield Format(FORMAT_ELF), NO_ADDRESS
elif is_freeze(buf):
yield Format(FORMAT_FREEZE), NO_ADDRESS
elif buf.startswith(MATCH_RESULT):
yield Format(FORMAT_RESULT), NO_ADDRESS
elif re.sub(rb"\s", b"", buf[:20]).startswith(MATCH_JSON_OBJECT):
# potential start of JSON object data without whitespace
# we don't know what it is exactly, but may support it (e.g. a dynamic CAPE sandbox report)
# skip verdict here and let subsequent code analyze this further
return
else:
# we likely end up here:
# 1. handling a file format (e.g. macho)
#
# for (1), this logic will need to be updated as the format is implemented.
logger.debug("unsupported file format: %s", binascii.hexlify(buf[:4]).decode("ascii"))
return
def extract_arch(buf) -> Iterator[Tuple[Feature, Address]]:
if buf.startswith(MATCH_PE):
yield from capa.features.extractors.pefile.extract_file_arch(pe=pefile.PE(data=buf))
elif buf.startswith(MATCH_RESULT):
yield Arch(ARCH_ANY), NO_ADDRESS
elif buf.startswith(MATCH_ELF):
with contextlib.closing(io.BytesIO(buf)) as f:
arch = capa.features.extractors.elf.detect_elf_arch(f)
if arch not in capa.features.common.VALID_ARCH:
logger.debug("unsupported arch: %s", arch)
return
yield Arch(arch), NO_ADDRESS
else:
# we likely end up here:
# 1. handling shellcode, or
# 2. handling a new file format (e.g. macho)
#
# for (1) we can't do much - its shellcode and all bets are off.
# we could maybe accept a further CLI argument to specify the arch,
# but i think this would be rarely used.
# rules that rely on arch conditions will fail to match on shellcode.
#
# for (2), this logic will need to be updated as the format is implemented.
logger.debug("unsupported file format: %s, will not guess Arch", binascii.hexlify(buf[:4]).decode("ascii"))
return
def extract_os(buf, os=OS_AUTO) -> Iterator[Tuple[Feature, Address]]:
if os != OS_AUTO:
yield OS(os), NO_ADDRESS
if buf.startswith(MATCH_PE):
yield OS(OS_WINDOWS), NO_ADDRESS
elif buf.startswith(MATCH_RESULT):
yield OS(OS_ANY), NO_ADDRESS
elif buf.startswith(MATCH_ELF):
with contextlib.closing(io.BytesIO(buf)) as f:
os = capa.features.extractors.elf.detect_elf_os(f)
if os not in capa.features.common.VALID_OS:
logger.debug("unsupported os: %s", os)
return
yield OS(os), NO_ADDRESS
else:
# we likely end up here:
# 1. handling shellcode, or
# 2. handling a new file format (e.g. macho)
#
# for (1) we can't do much - its shellcode and all bets are off.
# rules that rely on OS conditions will fail to match on shellcode.
#
# for (2), this logic will need to be updated as the format is implemented.
logger.debug("unsupported file format: %s, will not guess OS", binascii.hexlify(buf[:4]).decode("ascii"))
return

View File

@@ -1,161 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from __future__ import annotations
from typing import Dict, List, Tuple, Union, Iterator, Optional
from pathlib import Path
import dnfile
from dncil.cil.opcode import OpCodes
import capa.features.extractors
import capa.features.extractors.dotnetfile
import capa.features.extractors.dnfile.file
import capa.features.extractors.dnfile.insn
import capa.features.extractors.dnfile.function
from capa.features.common import Feature
from capa.features.address import NO_ADDRESS, Address, DNTokenAddress, DNTokenOffsetAddress
from capa.features.extractors.dnfile.types import DnType, DnUnmanagedMethod
from capa.features.extractors.base_extractor import (
BBHandle,
InsnHandle,
SampleHashes,
FunctionHandle,
StaticFeatureExtractor,
)
from capa.features.extractors.dnfile.helpers import (
get_dotnet_types,
get_dotnet_fields,
get_dotnet_managed_imports,
get_dotnet_managed_methods,
get_dotnet_unmanaged_imports,
get_dotnet_managed_method_bodies,
)
class DnFileFeatureExtractorCache:
def __init__(self, pe: dnfile.dnPE):
self.imports: Dict[int, Union[DnType, DnUnmanagedMethod]] = {}
self.native_imports: Dict[int, Union[DnType, DnUnmanagedMethod]] = {}
self.methods: Dict[int, Union[DnType, DnUnmanagedMethod]] = {}
self.fields: Dict[int, Union[DnType, DnUnmanagedMethod]] = {}
self.types: Dict[int, Union[DnType, DnUnmanagedMethod]] = {}
for import_ in get_dotnet_managed_imports(pe):
self.imports[import_.token] = import_
for native_import in get_dotnet_unmanaged_imports(pe):
self.native_imports[native_import.token] = native_import
for method in get_dotnet_managed_methods(pe):
self.methods[method.token] = method
for field in get_dotnet_fields(pe):
self.fields[field.token] = field
for type_ in get_dotnet_types(pe):
self.types[type_.token] = type_
def get_import(self, token: int) -> Optional[Union[DnType, DnUnmanagedMethod]]:
return self.imports.get(token)
def get_native_import(self, token: int) -> Optional[Union[DnType, DnUnmanagedMethod]]:
return self.native_imports.get(token)
def get_method(self, token: int) -> Optional[Union[DnType, DnUnmanagedMethod]]:
return self.methods.get(token)
def get_field(self, token: int) -> Optional[Union[DnType, DnUnmanagedMethod]]:
return self.fields.get(token)
def get_type(self, token: int) -> Optional[Union[DnType, DnUnmanagedMethod]]:
return self.types.get(token)
class DnfileFeatureExtractor(StaticFeatureExtractor):
def __init__(self, path: Path):
self.pe: dnfile.dnPE = dnfile.dnPE(str(path))
super().__init__(hashes=SampleHashes.from_bytes(path.read_bytes()))
# pre-compute .NET token lookup tables; each .NET method has access to this cache for feature extraction
# most relevant at instruction scope
self.token_cache: DnFileFeatureExtractorCache = DnFileFeatureExtractorCache(self.pe)
# pre-compute these because we'll yield them at *every* scope.
self.global_features: List[Tuple[Feature, Address]] = []
self.global_features.extend(capa.features.extractors.dotnetfile.extract_file_format())
self.global_features.extend(capa.features.extractors.dotnetfile.extract_file_os(pe=self.pe))
self.global_features.extend(capa.features.extractors.dotnetfile.extract_file_arch(pe=self.pe))
def get_base_address(self):
return NO_ADDRESS
def extract_global_features(self):
yield from self.global_features
def extract_file_features(self):
yield from capa.features.extractors.dnfile.file.extract_features(self.pe)
def get_functions(self) -> Iterator[FunctionHandle]:
# create a method lookup table
methods: Dict[Address, FunctionHandle] = {}
for token, method in get_dotnet_managed_method_bodies(self.pe):
fh: FunctionHandle = FunctionHandle(
address=DNTokenAddress(token),
inner=method,
ctx={"pe": self.pe, "calls_from": set(), "calls_to": set(), "cache": self.token_cache},
)
# method tokens should be unique
assert fh.address not in methods.keys()
methods[fh.address] = fh
# calculate unique calls to/from each method
for fh in methods.values():
for insn in fh.inner.instructions:
if insn.opcode not in (
OpCodes.Call,
OpCodes.Callvirt,
OpCodes.Jmp,
OpCodes.Newobj,
):
continue
address: DNTokenAddress = DNTokenAddress(insn.operand.value)
# record call to destination method; note: we only consider MethodDef methods for destinations
dest: Optional[FunctionHandle] = methods.get(address)
if dest is not None:
dest.ctx["calls_to"].add(fh.address)
# record call from source method; note: we record all unique calls from a MethodDef method, not just
# those calls to other MethodDef methods e.g. calls to imported MemberRef methods
fh.ctx["calls_from"].add(address)
yield from methods.values()
def extract_function_features(self, fh) -> Iterator[Tuple[Feature, Address]]:
yield from capa.features.extractors.dnfile.function.extract_features(fh)
def get_basic_blocks(self, f) -> Iterator[BBHandle]:
# each dotnet method is considered 1 basic block
yield BBHandle(
address=f.address,
inner=f.inner,
)
def extract_basic_block_features(self, fh, bbh):
# we don't support basic block features
yield from []
def get_instructions(self, fh, bbh):
for insn in bbh.inner.instructions:
yield InsnHandle(
address=DNTokenOffsetAddress(bbh.address, insn.offset - (fh.inner.offset + fh.inner.header_size)),
inner=insn,
)
def extract_insn_features(self, fh, bbh, ih) -> Iterator[Tuple[Feature, Address]]:
yield from capa.features.extractors.dnfile.insn.extract_features(fh, bbh, ih)

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@@ -1,63 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from __future__ import annotations
from typing import Tuple, Iterator
import dnfile
import capa.features.extractors.dotnetfile
from capa.features.file import Import, FunctionName
from capa.features.common import Class, Format, String, Feature, Namespace, Characteristic
from capa.features.address import Address
def extract_file_import_names(pe: dnfile.dnPE) -> Iterator[Tuple[Import, Address]]:
yield from capa.features.extractors.dotnetfile.extract_file_import_names(pe=pe)
def extract_file_format(pe: dnfile.dnPE) -> Iterator[Tuple[Format, Address]]:
yield from capa.features.extractors.dotnetfile.extract_file_format(pe=pe)
def extract_file_function_names(pe: dnfile.dnPE) -> Iterator[Tuple[FunctionName, Address]]:
yield from capa.features.extractors.dotnetfile.extract_file_function_names(pe=pe)
def extract_file_strings(pe: dnfile.dnPE) -> Iterator[Tuple[String, Address]]:
yield from capa.features.extractors.dotnetfile.extract_file_strings(pe=pe)
def extract_file_mixed_mode_characteristic_features(pe: dnfile.dnPE) -> Iterator[Tuple[Characteristic, Address]]:
yield from capa.features.extractors.dotnetfile.extract_file_mixed_mode_characteristic_features(pe=pe)
def extract_file_namespace_features(pe: dnfile.dnPE) -> Iterator[Tuple[Namespace, Address]]:
yield from capa.features.extractors.dotnetfile.extract_file_namespace_features(pe=pe)
def extract_file_class_features(pe: dnfile.dnPE) -> Iterator[Tuple[Class, Address]]:
yield from capa.features.extractors.dotnetfile.extract_file_class_features(pe=pe)
def extract_features(pe: dnfile.dnPE) -> Iterator[Tuple[Feature, Address]]:
for file_handler in FILE_HANDLERS:
for feature, address in file_handler(pe):
yield feature, address
FILE_HANDLERS = (
extract_file_import_names,
extract_file_function_names,
extract_file_strings,
extract_file_format,
extract_file_mixed_mode_characteristic_features,
extract_file_namespace_features,
extract_file_class_features,
)

View File

@@ -1,50 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from __future__ import annotations
import logging
from typing import Tuple, Iterator
from capa.features.common import Feature, Characteristic
from capa.features.address import Address
from capa.features.extractors.base_extractor import FunctionHandle
logger = logging.getLogger(__name__)
def extract_function_calls_to(fh: FunctionHandle) -> Iterator[Tuple[Characteristic, Address]]:
"""extract callers to a function"""
for dest in fh.ctx["calls_to"]:
yield Characteristic("calls to"), dest
def extract_function_calls_from(fh: FunctionHandle) -> Iterator[Tuple[Characteristic, Address]]:
"""extract callers from a function"""
for src in fh.ctx["calls_from"]:
yield Characteristic("calls from"), src
def extract_recursive_call(fh: FunctionHandle) -> Iterator[Tuple[Characteristic, Address]]:
"""extract recursive function call"""
if fh.address in fh.ctx["calls_to"]:
yield Characteristic("recursive call"), fh.address
def extract_function_loop(fh: FunctionHandle) -> Iterator[Tuple[Characteristic, Address]]:
"""extract loop indicators from a function"""
raise NotImplementedError()
def extract_features(fh: FunctionHandle) -> Iterator[Tuple[Feature, Address]]:
for func_handler in FUNCTION_HANDLERS:
for feature, addr in func_handler(fh):
yield feature, addr
FUNCTION_HANDLERS = (extract_function_calls_to, extract_function_calls_from, extract_recursive_call)

View File

@@ -1,448 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from __future__ import annotations
import logging
from typing import Dict, Tuple, Union, Iterator, Optional
import dnfile
from dncil.cil.body import CilMethodBody
from dncil.cil.error import MethodBodyFormatError
from dncil.clr.token import Token, StringToken, InvalidToken
from dncil.cil.body.reader import CilMethodBodyReaderBase
from capa.features.common import FeatureAccess
from capa.features.extractors.dnfile.types import DnType, DnUnmanagedMethod
logger = logging.getLogger(__name__)
class DnfileMethodBodyReader(CilMethodBodyReaderBase):
def __init__(self, pe: dnfile.dnPE, row: dnfile.mdtable.MethodDefRow):
self.pe: dnfile.dnPE = pe
self.offset: int = self.pe.get_offset_from_rva(row.Rva)
def read(self, n: int) -> bytes:
data: bytes = self.pe.get_data(self.pe.get_rva_from_offset(self.offset), n)
self.offset += n
return data
def tell(self) -> int:
return self.offset
def seek(self, offset: int) -> int:
self.offset = offset
return self.offset
def resolve_dotnet_token(pe: dnfile.dnPE, token: Token) -> Union[dnfile.base.MDTableRow, InvalidToken, str]:
"""map generic token to string or table row"""
assert pe.net is not None
assert pe.net.mdtables is not None
if isinstance(token, StringToken):
user_string: Optional[str] = read_dotnet_user_string(pe, token)
if user_string is None:
return InvalidToken(token.value)
return user_string
table: Optional[dnfile.base.ClrMetaDataTable] = pe.net.mdtables.tables.get(token.table)
if table is None:
# table index is not valid
return InvalidToken(token.value)
try:
return table.rows[token.rid - 1]
except IndexError:
# table index is valid but row index is not valid
return InvalidToken(token.value)
def read_dotnet_method_body(pe: dnfile.dnPE, row: dnfile.mdtable.MethodDefRow) -> Optional[CilMethodBody]:
"""read dotnet method body"""
try:
return CilMethodBody(DnfileMethodBodyReader(pe, row))
except MethodBodyFormatError as e:
logger.debug("failed to parse managed method body @ 0x%08x (%s)", row.Rva, e)
return None
def read_dotnet_user_string(pe: dnfile.dnPE, token: StringToken) -> Optional[str]:
"""read user string from #US stream"""
assert pe.net is not None
if pe.net.user_strings is None:
# stream may not exist (seen in obfuscated .NET)
logger.debug("#US stream does not exist for stream index 0x%08x", token.rid)
return None
try:
user_string: Optional[dnfile.stream.UserString] = pe.net.user_strings.get_us(token.rid)
except UnicodeDecodeError as e:
logger.debug("failed to decode #US stream index 0x%08x (%s)", token.rid, e)
return None
if user_string is None:
return None
return user_string.value
def get_dotnet_managed_imports(pe: dnfile.dnPE) -> Iterator[DnType]:
"""get managed imports from MemberRef table
see https://www.ntcore.com/files/dotnetformat.htm
10 - MemberRef Table
Each row represents an imported method
Class (index into the TypeRef, ModuleRef, MethodDef, TypeSpec or TypeDef tables)
Name (index into String heap)
01 - TypeRef Table
Each row represents an imported class, its namespace and the assembly which contains it
TypeName (index into String heap)
TypeNamespace (index into String heap)
"""
for rid, member_ref in iter_dotnet_table(pe, dnfile.mdtable.MemberRef.number):
assert isinstance(member_ref, dnfile.mdtable.MemberRefRow)
if not isinstance(member_ref.Class.row, dnfile.mdtable.TypeRefRow):
# only process class imports from TypeRef table
continue
token: int = calculate_dotnet_token_value(dnfile.mdtable.MemberRef.number, rid)
access: Optional[str]
# assume .NET imports starting with get_/set_ are used to access a property
if member_ref.Name.startswith("get_"):
access = FeatureAccess.READ
elif member_ref.Name.startswith("set_"):
access = FeatureAccess.WRITE
else:
access = None
member_ref_name: str = member_ref.Name
if member_ref_name.startswith(("get_", "set_")):
# remove get_/set_ from MemberRef name
member_ref_name = member_ref_name[4:]
typerefnamespace, typerefname = resolve_nested_typeref_name(
member_ref.Class.row_index, member_ref.Class.row, pe
)
yield DnType(
token,
typerefname,
namespace=typerefnamespace,
member=member_ref_name,
access=access,
)
def get_dotnet_methoddef_property_accessors(pe: dnfile.dnPE) -> Iterator[Tuple[int, str]]:
"""get MethodDef methods used to access properties
see https://www.ntcore.com/files/dotnetformat.htm
24 - MethodSemantics Table
Links Events and Properties to specific methods. For example one Event can be associated to more methods. A property uses this table to associate get/set methods.
Semantics (a 2-byte bitmask of type MethodSemanticsAttributes)
Method (index into the MethodDef table)
Association (index into the Event or Property table; more precisely, a HasSemantics coded index)
"""
for rid, method_semantics in iter_dotnet_table(pe, dnfile.mdtable.MethodSemantics.number):
assert isinstance(method_semantics, dnfile.mdtable.MethodSemanticsRow)
if method_semantics.Association.row is None:
logger.debug("MethodSemantics[0x%X] Association row is None", rid)
continue
if isinstance(method_semantics.Association.row, dnfile.mdtable.EventRow):
# ignore events
logger.debug("MethodSemantics[0x%X] ignoring Event", rid)
continue
if method_semantics.Method.table is None:
logger.debug("MethodSemantics[0x%X] Method table is None", rid)
continue
token: int = calculate_dotnet_token_value(
method_semantics.Method.table.number, method_semantics.Method.row_index
)
if method_semantics.Semantics.msSetter:
yield token, FeatureAccess.WRITE
elif method_semantics.Semantics.msGetter:
yield token, FeatureAccess.READ
def get_dotnet_managed_methods(pe: dnfile.dnPE) -> Iterator[DnType]:
"""get managed method names from TypeDef table
see https://www.ntcore.com/files/dotnetformat.htm
02 - TypeDef Table
Each row represents a class in the current assembly.
TypeName (index into String heap)
TypeNamespace (index into String heap)
MethodList (index into MethodDef table; it marks the first of a contiguous run of Methods owned by this Type)
"""
nested_class_table = get_dotnet_nested_class_table_index(pe)
accessor_map: Dict[int, str] = {}
for methoddef, methoddef_access in get_dotnet_methoddef_property_accessors(pe):
accessor_map[methoddef] = methoddef_access
for rid, typedef in iter_dotnet_table(pe, dnfile.mdtable.TypeDef.number):
assert isinstance(typedef, dnfile.mdtable.TypeDefRow)
for idx, method in enumerate(typedef.MethodList):
if method.table is None:
logger.debug("TypeDef[0x%X] MethodList[0x%X] table is None", rid, idx)
continue
if method.row is None:
logger.debug("TypeDef[0x%X] MethodList[0x%X] row is None", rid, idx)
continue
token: int = calculate_dotnet_token_value(method.table.number, method.row_index)
access: Optional[str] = accessor_map.get(token)
method_name: str = method.row.Name
if method_name.startswith(("get_", "set_")):
# remove get_/set_
method_name = method_name[4:]
typedefnamespace, typedefname = resolve_nested_typedef_name(nested_class_table, rid, typedef, pe)
yield DnType(token, typedefname, namespace=typedefnamespace, member=method_name, access=access)
def get_dotnet_fields(pe: dnfile.dnPE) -> Iterator[DnType]:
"""get fields from TypeDef table
see https://www.ntcore.com/files/dotnetformat.htm
02 - TypeDef Table
Each row represents a class in the current assembly.
TypeName (index into String heap)
TypeNamespace (index into String heap)
FieldList (index into Field table; it marks the first of a contiguous run of Fields owned by this Type)
"""
nested_class_table = get_dotnet_nested_class_table_index(pe)
for rid, typedef in iter_dotnet_table(pe, dnfile.mdtable.TypeDef.number):
assert isinstance(typedef, dnfile.mdtable.TypeDefRow)
for idx, field in enumerate(typedef.FieldList):
if field.table is None:
logger.debug("TypeDef[0x%X] FieldList[0x%X] table is None", rid, idx)
continue
if field.row is None:
logger.debug("TypeDef[0x%X] FieldList[0x%X] row is None", rid, idx)
continue
typedefnamespace, typedefname = resolve_nested_typedef_name(nested_class_table, rid, typedef, pe)
token: int = calculate_dotnet_token_value(field.table.number, field.row_index)
yield DnType(token, typedefname, namespace=typedefnamespace, member=field.row.Name)
def get_dotnet_managed_method_bodies(pe: dnfile.dnPE) -> Iterator[Tuple[int, CilMethodBody]]:
"""get managed methods from MethodDef table"""
for rid, method_def in iter_dotnet_table(pe, dnfile.mdtable.MethodDef.number):
assert isinstance(method_def, dnfile.mdtable.MethodDefRow)
if not method_def.ImplFlags.miIL or any((method_def.Flags.mdAbstract, method_def.Flags.mdPinvokeImpl)):
# skip methods that do not have a method body
continue
body: Optional[CilMethodBody] = read_dotnet_method_body(pe, method_def)
if body is None:
logger.debug("MethodDef[0x%X] method body is None", rid)
continue
token: int = calculate_dotnet_token_value(dnfile.mdtable.MethodDef.number, rid)
yield token, body
def get_dotnet_unmanaged_imports(pe: dnfile.dnPE) -> Iterator[DnUnmanagedMethod]:
"""get unmanaged imports from ImplMap table
see https://www.ntcore.com/files/dotnetformat.htm
28 - ImplMap Table
ImplMap table holds information about unmanaged methods that can be reached from managed code, using PInvoke dispatch
MemberForwarded (index into the Field or MethodDef table; more precisely, a MemberForwarded coded index)
ImportName (index into the String heap)
ImportScope (index into the ModuleRef table)
"""
for rid, impl_map in iter_dotnet_table(pe, dnfile.mdtable.ImplMap.number):
assert isinstance(impl_map, dnfile.mdtable.ImplMapRow)
module: str
if impl_map.ImportScope.row is None:
logger.debug("ImplMap[0x%X] ImportScope row is None", rid)
module = ""
else:
module = impl_map.ImportScope.row.Name
method: str = impl_map.ImportName
member_forward_table: int
if impl_map.MemberForwarded.table is None:
logger.debug("ImplMap[0x%X] MemberForwarded table is None", rid)
continue
else:
member_forward_table = impl_map.MemberForwarded.table.number
member_forward_row: int = impl_map.MemberForwarded.row_index
# ECMA says "Each row of the ImplMap table associates a row in the MethodDef table (MemberForwarded) with the
# name of a routine (ImportName) in some unmanaged DLL (ImportScope)"; so we calculate and map the MemberForwarded
# MethodDef table token to help us later record native import method calls made from CIL
token: int = calculate_dotnet_token_value(member_forward_table, member_forward_row)
# like Kernel32.dll
if module and "." in module:
module = module.split(".")[0]
# like kernel32.CreateFileA
yield DnUnmanagedMethod(token, module, method)
def get_dotnet_table_row(pe: dnfile.dnPE, table_index: int, row_index: int) -> Optional[dnfile.base.MDTableRow]:
assert pe.net is not None
assert pe.net.mdtables is not None
if row_index - 1 <= 0:
return None
try:
table = pe.net.mdtables.tables.get(table_index, [])
return table[row_index - 1]
except IndexError:
return None
def resolve_nested_typedef_name(
nested_class_table: dict, index: int, typedef: dnfile.mdtable.TypeDefRow, pe: dnfile.dnPE
) -> Tuple[str, Tuple[str, ...]]:
"""Resolves all nested TypeDef class names. Returns the namespace as a str and the nested TypeRef name as a tuple"""
if index in nested_class_table:
typedef_name = []
name = typedef.TypeName
# Append the current typedef name
typedef_name.append(name)
while nested_class_table[index] in nested_class_table:
# Iterate through the typedef table to resolve the nested name
table_row = get_dotnet_table_row(pe, dnfile.mdtable.TypeDef.number, nested_class_table[index])
if table_row is None:
return typedef.TypeNamespace, tuple(typedef_name[::-1])
name = table_row.TypeName
typedef_name.append(name)
index = nested_class_table[index]
# Document the root enclosing details
table_row = get_dotnet_table_row(pe, dnfile.mdtable.TypeDef.number, nested_class_table[index])
if table_row is None:
return typedef.TypeNamespace, tuple(typedef_name[::-1])
enclosing_name = table_row.TypeName
typedef_name.append(enclosing_name)
return table_row.TypeNamespace, tuple(typedef_name[::-1])
else:
return typedef.TypeNamespace, (typedef.TypeName,)
def resolve_nested_typeref_name(
index: int, typeref: dnfile.mdtable.TypeRefRow, pe: dnfile.dnPE
) -> Tuple[str, Tuple[str, ...]]:
"""Resolves all nested TypeRef class names. Returns the namespace as a str and the nested TypeRef name as a tuple"""
# If the ResolutionScope decodes to a typeRef type then it is nested
if isinstance(typeref.ResolutionScope.table, dnfile.mdtable.TypeRef):
typeref_name = []
name = typeref.TypeName
# Not appending the current typeref name to avoid potential duplicate
# Validate index
table_row = get_dotnet_table_row(pe, dnfile.mdtable.TypeRef.number, index)
if table_row is None:
return typeref.TypeNamespace, (typeref.TypeName,)
while isinstance(table_row.ResolutionScope.table, dnfile.mdtable.TypeRef):
# Iterate through the typeref table to resolve the nested name
typeref_name.append(name)
name = table_row.TypeName
table_row = get_dotnet_table_row(pe, dnfile.mdtable.TypeRef.number, table_row.ResolutionScope.row_index)
if table_row is None:
return typeref.TypeNamespace, tuple(typeref_name[::-1])
# Document the root enclosing details
typeref_name.append(table_row.TypeName)
return table_row.TypeNamespace, tuple(typeref_name[::-1])
else:
return typeref.TypeNamespace, (typeref.TypeName,)
def get_dotnet_nested_class_table_index(pe: dnfile.dnPE) -> Dict[int, int]:
"""Build index for EnclosingClass based off the NestedClass row index in the nestedclass table"""
nested_class_table = {}
# Used to find nested classes in typedef
for _, nestedclass in iter_dotnet_table(pe, dnfile.mdtable.NestedClass.number):
assert isinstance(nestedclass, dnfile.mdtable.NestedClassRow)
nested_class_table[nestedclass.NestedClass.row_index] = nestedclass.EnclosingClass.row_index
return nested_class_table
def get_dotnet_types(pe: dnfile.dnPE) -> Iterator[DnType]:
"""get .NET types from TypeDef and TypeRef tables"""
nested_class_table = get_dotnet_nested_class_table_index(pe)
for rid, typedef in iter_dotnet_table(pe, dnfile.mdtable.TypeDef.number):
assert isinstance(typedef, dnfile.mdtable.TypeDefRow)
typedefnamespace, typedefname = resolve_nested_typedef_name(nested_class_table, rid, typedef, pe)
typedef_token: int = calculate_dotnet_token_value(dnfile.mdtable.TypeDef.number, rid)
yield DnType(typedef_token, typedefname, namespace=typedefnamespace)
for rid, typeref in iter_dotnet_table(pe, dnfile.mdtable.TypeRef.number):
assert isinstance(typeref, dnfile.mdtable.TypeRefRow)
typerefnamespace, typerefname = resolve_nested_typeref_name(typeref.ResolutionScope.row_index, typeref, pe)
typeref_token: int = calculate_dotnet_token_value(dnfile.mdtable.TypeRef.number, rid)
yield DnType(typeref_token, typerefname, namespace=typerefnamespace)
def calculate_dotnet_token_value(table: int, rid: int) -> int:
return ((table & 0xFF) << Token.TABLE_SHIFT) | (rid & Token.RID_MASK)
def is_dotnet_mixed_mode(pe: dnfile.dnPE) -> bool:
assert pe.net is not None
assert pe.net.Flags is not None
return not bool(pe.net.Flags.CLR_ILONLY)
def iter_dotnet_table(pe: dnfile.dnPE, table_index: int) -> Iterator[Tuple[int, dnfile.base.MDTableRow]]:
assert pe.net is not None
assert pe.net.mdtables is not None
for rid, row in enumerate(pe.net.mdtables.tables.get(table_index, [])):
# .NET tables are 1-indexed
yield rid + 1, row

View File

@@ -1,227 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from __future__ import annotations
import logging
from typing import TYPE_CHECKING, Tuple, Union, Iterator, Optional
if TYPE_CHECKING:
from capa.features.extractors.dnfile.extractor import DnFileFeatureExtractorCache
import dnfile
from dncil.clr.token import Token, StringToken, InvalidToken
from dncil.cil.opcode import OpCodes
import capa.features.extractors.helpers
from capa.features.insn import API, Number, Property
from capa.features.common import Class, String, Feature, Namespace, FeatureAccess, Characteristic
from capa.features.address import Address
from capa.features.extractors.dnfile.types import DnType, DnUnmanagedMethod
from capa.features.extractors.base_extractor import BBHandle, InsnHandle, FunctionHandle
from capa.features.extractors.dnfile.helpers import (
resolve_dotnet_token,
read_dotnet_user_string,
calculate_dotnet_token_value,
)
logger = logging.getLogger(__name__)
def get_callee(
pe: dnfile.dnPE, cache: DnFileFeatureExtractorCache, token: Token
) -> Optional[Union[DnType, DnUnmanagedMethod]]:
"""map .NET token to un/managed (generic) method"""
token_: int
if token.table == dnfile.mdtable.MethodSpec.number:
# map MethodSpec to MethodDef or MemberRef
row: Union[dnfile.base.MDTableRow, InvalidToken, str] = resolve_dotnet_token(pe, token)
assert isinstance(row, dnfile.mdtable.MethodSpecRow)
if row.Method.table is None:
logger.debug("MethodSpec[0x%X] Method table is None", token.rid)
return None
token_ = calculate_dotnet_token_value(row.Method.table.number, row.Method.row_index)
else:
token_ = token.value
callee: Optional[Union[DnType, DnUnmanagedMethod]] = cache.get_import(token_)
if callee is None:
# we must check unmanaged imports before managed methods because we map forwarded managed methods
# to their unmanaged imports; we prefer a forwarded managed method be mapped to its unmanaged import for analysis
callee = cache.get_native_import(token_)
if callee is None:
callee = cache.get_method(token_)
return callee
def extract_insn_api_features(fh: FunctionHandle, bh, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""parse instruction API features"""
if ih.inner.opcode not in (
OpCodes.Call,
OpCodes.Callvirt,
OpCodes.Jmp,
OpCodes.Newobj,
):
return
callee: Optional[Union[DnType, DnUnmanagedMethod]] = get_callee(fh.ctx["pe"], fh.ctx["cache"], ih.inner.operand)
if isinstance(callee, DnType):
# ignore methods used to access properties
if callee.access is None:
# like System.IO.File::Delete
yield API(str(callee)), ih.address
elif isinstance(callee, DnUnmanagedMethod):
# like kernel32.CreateFileA
for name in capa.features.extractors.helpers.generate_symbols(callee.module, callee.method):
yield API(name), ih.address
def extract_insn_property_features(fh: FunctionHandle, bh, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""parse instruction property features"""
name: Optional[str] = None
access: Optional[str] = None
if ih.inner.opcode in (OpCodes.Call, OpCodes.Callvirt, OpCodes.Jmp):
# property access via MethodDef or MemberRef
callee: Optional[Union[DnType, DnUnmanagedMethod]] = get_callee(fh.ctx["pe"], fh.ctx["cache"], ih.inner.operand)
if isinstance(callee, DnType):
if callee.access is not None:
name = str(callee)
access = callee.access
elif ih.inner.opcode in (OpCodes.Ldfld, OpCodes.Ldflda, OpCodes.Ldsfld, OpCodes.Ldsflda):
# property read via Field
read_field: Optional[Union[DnType, DnUnmanagedMethod]] = fh.ctx["cache"].get_field(ih.inner.operand.value)
if read_field is not None:
name = str(read_field)
access = FeatureAccess.READ
elif ih.inner.opcode in (OpCodes.Stfld, OpCodes.Stsfld):
# property write via Field
write_field: Optional[Union[DnType, DnUnmanagedMethod]] = fh.ctx["cache"].get_field(ih.inner.operand.value)
if write_field is not None:
name = str(write_field)
access = FeatureAccess.WRITE
if name is not None:
if access is not None:
yield Property(name, access=access), ih.address
yield Property(name), ih.address
def extract_insn_namespace_class_features(
fh: FunctionHandle, bh, ih: InsnHandle
) -> Iterator[Tuple[Union[Namespace, Class], Address]]:
"""parse instruction namespace and class features"""
type_: Optional[Union[DnType, DnUnmanagedMethod]] = None
if ih.inner.opcode in (
OpCodes.Call,
OpCodes.Callvirt,
OpCodes.Jmp,
OpCodes.Ldvirtftn,
OpCodes.Ldftn,
OpCodes.Newobj,
):
# method call - includes managed methods (MethodDef, TypeRef) and properties (MethodSemantics, TypeRef)
type_ = get_callee(fh.ctx["pe"], fh.ctx["cache"], ih.inner.operand)
elif ih.inner.opcode in (
OpCodes.Ldfld,
OpCodes.Ldflda,
OpCodes.Ldsfld,
OpCodes.Ldsflda,
OpCodes.Stfld,
OpCodes.Stsfld,
):
# field access
type_ = fh.ctx["cache"].get_field(ih.inner.operand.value)
# ECMA 335 VI.C.4.10
elif ih.inner.opcode in (
OpCodes.Initobj,
OpCodes.Box,
OpCodes.Castclass,
OpCodes.Cpobj,
OpCodes.Isinst,
OpCodes.Ldelem,
OpCodes.Ldelema,
OpCodes.Ldobj,
OpCodes.Mkrefany,
OpCodes.Newarr,
OpCodes.Refanyval,
OpCodes.Sizeof,
OpCodes.Stobj,
OpCodes.Unbox,
OpCodes.Constrained,
OpCodes.Stelem,
OpCodes.Unbox_Any,
):
# type access
type_ = fh.ctx["cache"].get_type(ih.inner.operand.value)
if isinstance(type_, DnType):
yield Class(DnType.format_name(type_.class_, namespace=type_.namespace)), ih.address
if type_.namespace:
yield Namespace(type_.namespace), ih.address
def extract_insn_number_features(fh, bh, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""parse instruction number features"""
if ih.inner.is_ldc():
yield Number(ih.inner.get_ldc()), ih.address
def extract_insn_string_features(fh: FunctionHandle, bh, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""parse instruction string features"""
if not ih.inner.is_ldstr():
return
if not isinstance(ih.inner.operand, StringToken):
return
user_string: Optional[str] = read_dotnet_user_string(fh.ctx["pe"], ih.inner.operand)
if user_string is None:
return
if len(user_string) >= 4:
yield String(user_string), ih.address
def extract_unmanaged_call_characteristic_features(
fh: FunctionHandle, bb: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Characteristic, Address]]:
if ih.inner.opcode not in (OpCodes.Call, OpCodes.Callvirt, OpCodes.Jmp):
return
row: Union[str, InvalidToken, dnfile.base.MDTableRow] = resolve_dotnet_token(fh.ctx["pe"], ih.inner.operand)
if not isinstance(row, dnfile.mdtable.MethodDefRow):
return
if any((row.Flags.mdPinvokeImpl, row.ImplFlags.miUnmanaged, row.ImplFlags.miNative)):
yield Characteristic("unmanaged call"), ih.address
def extract_features(fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""extract instruction features"""
for inst_handler in INSTRUCTION_HANDLERS:
for feature, addr in inst_handler(fh, bbh, ih):
assert isinstance(addr, Address)
yield feature, addr
INSTRUCTION_HANDLERS = (
extract_insn_api_features,
extract_insn_property_features,
extract_insn_number_features,
extract_insn_string_features,
extract_insn_namespace_class_features,
extract_unmanaged_call_characteristic_features,
)

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@@ -1,80 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import Tuple, Optional
class DnType:
def __init__(
self, token: int, class_: Tuple[str, ...], namespace: str = "", member: str = "", access: Optional[str] = None
):
self.token: int = token
self.access: Optional[str] = access
self.namespace: str = namespace
self.class_: Tuple[str, ...] = class_
if member == ".ctor":
member = "ctor"
if member == ".cctor":
member = "cctor"
self.member: str = member
def __hash__(self):
return hash((self.token, self.access, self.namespace, self.class_, self.member))
def __eq__(self, other):
return (
self.token == other.token
and self.access == other.access
and self.namespace == other.namespace
and self.class_ == other.class_
and self.member == other.member
)
def __str__(self):
return DnType.format_name(self.class_, namespace=self.namespace, member=self.member)
def __repr__(self):
return str(self)
@staticmethod
def format_name(class_: Tuple[str, ...], namespace: str = "", member: str = ""):
if len(class_) > 1:
class_str = "/".join(class_) # Concat items in tuple, separated by a "/"
else:
class_str = "".join(class_) # Convert tuple to str
# like File::OpenRead
name: str = f"{class_str}::{member}" if member else class_str
if namespace:
# like System.IO.File::OpenRead
name = f"{namespace}.{name}"
return name
class DnUnmanagedMethod:
def __init__(self, token: int, module: str, method: str):
self.token: int = token
self.module: str = module
self.method: str = method
def __hash__(self):
return hash((self.token, self.module, self.method))
def __eq__(self, other):
return self.token == other.token and self.module == other.module and self.method == other.method
def __str__(self):
return DnUnmanagedMethod.format_name(self.module, self.method)
def __repr__(self):
return str(self)
@staticmethod
def format_name(module, method):
return f"{module}.{method}"

View File

@@ -1,248 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
from typing import Tuple, Iterator
from pathlib import Path
import dnfile
import pefile
import capa.features.extractors.helpers
from capa.features.file import Import, FunctionName
from capa.features.common import (
OS,
OS_ANY,
ARCH_ANY,
ARCH_I386,
FORMAT_PE,
ARCH_AMD64,
FORMAT_DOTNET,
Arch,
Class,
Format,
String,
Feature,
Namespace,
Characteristic,
)
from capa.features.address import NO_ADDRESS, Address, DNTokenAddress
from capa.features.extractors.dnfile.types import DnType
from capa.features.extractors.base_extractor import SampleHashes, StaticFeatureExtractor
from capa.features.extractors.dnfile.helpers import (
iter_dotnet_table,
is_dotnet_mixed_mode,
get_dotnet_managed_imports,
get_dotnet_managed_methods,
resolve_nested_typedef_name,
resolve_nested_typeref_name,
calculate_dotnet_token_value,
get_dotnet_unmanaged_imports,
get_dotnet_nested_class_table_index,
)
logger = logging.getLogger(__name__)
def extract_file_format(**kwargs) -> Iterator[Tuple[Format, Address]]:
yield Format(FORMAT_PE), NO_ADDRESS
yield Format(FORMAT_DOTNET), NO_ADDRESS
def extract_file_import_names(pe: dnfile.dnPE, **kwargs) -> Iterator[Tuple[Import, Address]]:
for method in get_dotnet_managed_imports(pe):
# like System.IO.File::OpenRead
yield Import(str(method)), DNTokenAddress(method.token)
for imp in get_dotnet_unmanaged_imports(pe):
# like kernel32.CreateFileA
for name in capa.features.extractors.helpers.generate_symbols(imp.module, imp.method, include_dll=True):
yield Import(name), DNTokenAddress(imp.token)
def extract_file_function_names(pe: dnfile.dnPE, **kwargs) -> Iterator[Tuple[FunctionName, Address]]:
for method in get_dotnet_managed_methods(pe):
yield FunctionName(str(method)), DNTokenAddress(method.token)
def extract_file_namespace_features(pe: dnfile.dnPE, **kwargs) -> Iterator[Tuple[Namespace, Address]]:
"""emit namespace features from TypeRef and TypeDef tables"""
# namespaces may be referenced multiple times, so we need to filter
namespaces = set()
for _, typedef in iter_dotnet_table(pe, dnfile.mdtable.TypeDef.number):
# emit internal .NET namespaces
assert isinstance(typedef, dnfile.mdtable.TypeDefRow)
namespaces.add(typedef.TypeNamespace)
for _, typeref in iter_dotnet_table(pe, dnfile.mdtable.TypeRef.number):
# emit external .NET namespaces
assert isinstance(typeref, dnfile.mdtable.TypeRefRow)
namespaces.add(typeref.TypeNamespace)
# namespaces may be empty, discard
namespaces.discard("")
for namespace in namespaces:
# namespace do not have an associated token, so we yield 0x0
yield Namespace(namespace), NO_ADDRESS
def extract_file_class_features(pe: dnfile.dnPE, **kwargs) -> Iterator[Tuple[Class, Address]]:
"""emit class features from TypeRef and TypeDef tables"""
nested_class_table = get_dotnet_nested_class_table_index(pe)
for rid, typedef in iter_dotnet_table(pe, dnfile.mdtable.TypeDef.number):
# emit internal .NET classes
assert isinstance(typedef, dnfile.mdtable.TypeDefRow)
typedefnamespace, typedefname = resolve_nested_typedef_name(nested_class_table, rid, typedef, pe)
token = calculate_dotnet_token_value(dnfile.mdtable.TypeDef.number, rid)
yield Class(DnType.format_name(typedefname, namespace=typedefnamespace)), DNTokenAddress(token)
for rid, typeref in iter_dotnet_table(pe, dnfile.mdtable.TypeRef.number):
# emit external .NET classes
assert isinstance(typeref, dnfile.mdtable.TypeRefRow)
typerefnamespace, typerefname = resolve_nested_typeref_name(typeref.ResolutionScope.row_index, typeref, pe)
token = calculate_dotnet_token_value(dnfile.mdtable.TypeRef.number, rid)
yield Class(DnType.format_name(typerefname, namespace=typerefnamespace)), DNTokenAddress(token)
def extract_file_os(**kwargs) -> Iterator[Tuple[OS, Address]]:
yield OS(OS_ANY), NO_ADDRESS
def extract_file_arch(pe: dnfile.dnPE, **kwargs) -> Iterator[Tuple[Arch, Address]]:
# to distinguish in more detail, see https://stackoverflow.com/a/23614024/10548020
# .NET 4.5 added option: any CPU, 32-bit preferred
assert pe.net is not None
assert pe.net.Flags is not None
if pe.net.Flags.CLR_32BITREQUIRED and pe.PE_TYPE == pefile.OPTIONAL_HEADER_MAGIC_PE:
yield Arch(ARCH_I386), NO_ADDRESS
elif not pe.net.Flags.CLR_32BITREQUIRED and pe.PE_TYPE == pefile.OPTIONAL_HEADER_MAGIC_PE_PLUS:
yield Arch(ARCH_AMD64), NO_ADDRESS
else:
yield Arch(ARCH_ANY), NO_ADDRESS
def extract_file_strings(pe: dnfile.dnPE, **kwargs) -> Iterator[Tuple[String, Address]]:
yield from capa.features.extractors.common.extract_file_strings(pe.__data__)
def extract_file_mixed_mode_characteristic_features(
pe: dnfile.dnPE, **kwargs
) -> Iterator[Tuple[Characteristic, Address]]:
if is_dotnet_mixed_mode(pe):
yield Characteristic("mixed mode"), NO_ADDRESS
def extract_file_features(pe: dnfile.dnPE) -> Iterator[Tuple[Feature, Address]]:
for file_handler in FILE_HANDLERS:
for feature, addr in file_handler(pe=pe): # type: ignore
yield feature, addr
FILE_HANDLERS = (
extract_file_import_names,
extract_file_function_names,
extract_file_strings,
extract_file_format,
extract_file_mixed_mode_characteristic_features,
extract_file_namespace_features,
extract_file_class_features,
)
def extract_global_features(pe: dnfile.dnPE) -> Iterator[Tuple[Feature, Address]]:
for handler in GLOBAL_HANDLERS:
for feature, va in handler(pe=pe): # type: ignore
yield feature, va
GLOBAL_HANDLERS = (
extract_file_os,
extract_file_arch,
)
class DotnetFileFeatureExtractor(StaticFeatureExtractor):
def __init__(self, path: Path):
super().__init__(hashes=SampleHashes.from_bytes(path.read_bytes()))
self.path: Path = path
self.pe: dnfile.dnPE = dnfile.dnPE(str(path))
def get_base_address(self):
return NO_ADDRESS
def get_entry_point(self) -> int:
# self.pe.net.Flags.CLT_NATIVE_ENTRYPOINT
# True: native EP: Token
# False: managed EP: RVA
assert self.pe.net is not None
assert self.pe.net.struct is not None
return self.pe.net.struct.EntryPointTokenOrRva
def extract_global_features(self):
yield from extract_global_features(self.pe)
def extract_file_features(self):
yield from extract_file_features(self.pe)
def is_dotnet_file(self) -> bool:
return bool(self.pe.net)
def is_mixed_mode(self) -> bool:
return is_dotnet_mixed_mode(self.pe)
def get_runtime_version(self) -> Tuple[int, int]:
assert self.pe.net is not None
assert self.pe.net.struct is not None
assert self.pe.net.struct.MajorRuntimeVersion is not None
assert self.pe.net.struct.MinorRuntimeVersion is not None
return self.pe.net.struct.MajorRuntimeVersion, self.pe.net.struct.MinorRuntimeVersion
def get_meta_version_string(self) -> str:
assert self.pe.net is not None
assert self.pe.net.metadata is not None
assert self.pe.net.metadata.struct is not None
assert self.pe.net.metadata.struct.Version is not None
vbuf = self.pe.net.metadata.struct.Version
assert isinstance(vbuf, bytes)
return vbuf.rstrip(b"\x00").decode("utf-8")
def get_functions(self):
raise NotImplementedError("DotnetFileFeatureExtractor can only be used to extract file features")
def extract_function_features(self, f):
raise NotImplementedError("DotnetFileFeatureExtractor can only be used to extract file features")
def get_basic_blocks(self, f):
raise NotImplementedError("DotnetFileFeatureExtractor can only be used to extract file features")
def extract_basic_block_features(self, f, bb):
raise NotImplementedError("DotnetFileFeatureExtractor can only be used to extract file features")
def get_instructions(self, f, bb):
raise NotImplementedError("DotnetFileFeatureExtractor can only be used to extract file features")
def extract_insn_features(self, f, bb, insn):
raise NotImplementedError("DotnetFileFeatureExtractor can only be used to extract file features")
def is_library_function(self, va):
raise NotImplementedError("DotnetFileFeatureExtractor can only be used to extract file features")
def get_function_name(self, va):
raise NotImplementedError("DotnetFileFeatureExtractor can only be used to extract file features")

File diff suppressed because it is too large Load Diff

View File

@@ -1,203 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import io
import logging
from typing import Tuple, Iterator
from pathlib import Path
from elftools.elf.elffile import ELFFile, SymbolTableSection
from elftools.elf.relocation import RelocationSection
import capa.features.extractors.common
from capa.features.file import Export, Import, Section
from capa.features.common import OS, FORMAT_ELF, Arch, Format, Feature
from capa.features.address import NO_ADDRESS, FileOffsetAddress, AbsoluteVirtualAddress
from capa.features.extractors.base_extractor import SampleHashes, StaticFeatureExtractor
logger = logging.getLogger(__name__)
def extract_file_export_names(elf: ELFFile, **kwargs):
for section in elf.iter_sections():
if not isinstance(section, SymbolTableSection):
continue
if section["sh_entsize"] == 0:
logger.debug("Symbol table '%s' has a sh_entsize of zero!", section.name)
continue
logger.debug("Symbol table '%s' contains %s entries:", section.name, section.num_symbols())
for symbol in section.iter_symbols():
# The following conditions are based on the following article
# http://www.m4b.io/elf/export/binary/analysis/2015/05/25/what-is-an-elf-export.html
if not symbol.name:
continue
if symbol.entry.st_info.type not in ["STT_FUNC", "STT_OBJECT", "STT_IFUNC"]:
continue
if symbol.entry.st_value == 0:
continue
if symbol.entry.st_shndx == "SHN_UNDEF":
continue
yield Export(symbol.name), AbsoluteVirtualAddress(symbol.entry.st_value)
def extract_file_import_names(elf: ELFFile, **kwargs):
# Create a dictionary to store symbol names by their index
symbol_names = {}
# Extract symbol names and store them in the dictionary
for section in elf.iter_sections():
if not isinstance(section, SymbolTableSection):
continue
for _, symbol in enumerate(section.iter_symbols()):
# The following conditions are based on the following article
# http://www.m4b.io/elf/export/binary/analysis/2015/05/25/what-is-an-elf-export.html
if not symbol.name:
continue
if symbol.entry.st_info.type not in ["STT_FUNC", "STT_OBJECT", "STT_IFUNC"]:
continue
if symbol.entry.st_value != 0:
continue
if symbol.entry.st_shndx != "SHN_UNDEF":
continue
if symbol.entry.st_name == 0:
continue
symbol_names[_] = symbol.name
for section in elf.iter_sections():
if not isinstance(section, RelocationSection):
continue
if section["sh_entsize"] == 0:
logger.debug("Symbol table '%s' has a sh_entsize of zero!", section.name)
continue
logger.debug("Symbol table '%s' contains %s entries:", section.name, section.num_relocations())
for relocation in section.iter_relocations():
# Extract the symbol name from the symbol table using the symbol index in the relocation
if relocation["r_info_sym"] not in symbol_names:
continue
yield Import(symbol_names[relocation["r_info_sym"]]), FileOffsetAddress(relocation["r_offset"])
def extract_file_section_names(elf: ELFFile, **kwargs):
for section in elf.iter_sections():
if section.name:
yield Section(section.name), AbsoluteVirtualAddress(section.header.sh_addr)
elif section.is_null():
yield Section("NULL"), AbsoluteVirtualAddress(section.header.sh_addr)
def extract_file_strings(buf, **kwargs):
yield from capa.features.extractors.common.extract_file_strings(buf)
def extract_file_os(elf: ELFFile, buf, **kwargs):
# our current approach does not always get an OS value, e.g. for packed samples
# for file limitation purposes, we're more lax here
try:
os_tuple = next(capa.features.extractors.common.extract_os(buf))
yield os_tuple
except StopIteration:
yield OS("unknown"), NO_ADDRESS
def extract_file_format(**kwargs):
yield Format(FORMAT_ELF), NO_ADDRESS
def extract_file_arch(elf: ELFFile, **kwargs):
arch = elf.get_machine_arch()
if arch == "x86":
yield Arch("i386"), NO_ADDRESS
elif arch == "x64":
yield Arch("amd64"), NO_ADDRESS
else:
logger.warning("unsupported architecture: %s", arch)
def extract_file_features(elf: ELFFile, buf: bytes) -> Iterator[Tuple[Feature, int]]:
for file_handler in FILE_HANDLERS:
for feature, addr in file_handler(elf=elf, buf=buf): # type: ignore
yield feature, addr
FILE_HANDLERS = (
extract_file_export_names,
extract_file_import_names,
extract_file_section_names,
extract_file_strings,
# no library matching
extract_file_format,
)
def extract_global_features(elf: ELFFile, buf: bytes) -> Iterator[Tuple[Feature, int]]:
for global_handler in GLOBAL_HANDLERS:
for feature, addr in global_handler(elf=elf, buf=buf): # type: ignore
yield feature, addr
GLOBAL_HANDLERS = (
extract_file_os,
extract_file_arch,
)
class ElfFeatureExtractor(StaticFeatureExtractor):
def __init__(self, path: Path):
super().__init__(SampleHashes.from_bytes(path.read_bytes()))
self.path: Path = path
self.elf = ELFFile(io.BytesIO(path.read_bytes()))
def get_base_address(self):
# virtual address of the first segment with type LOAD
for segment in self.elf.iter_segments():
if segment.header.p_type == "PT_LOAD":
return AbsoluteVirtualAddress(segment.header.p_vaddr)
def extract_global_features(self):
buf = self.path.read_bytes()
for feature, addr in extract_global_features(self.elf, buf):
yield feature, addr
def extract_file_features(self):
buf = self.path.read_bytes()
for feature, addr in extract_file_features(self.elf, buf):
yield feature, addr
def get_functions(self):
raise NotImplementedError("ElfFeatureExtractor can only be used to extract file features")
def extract_function_features(self, f):
raise NotImplementedError("ElfFeatureExtractor can only be used to extract file features")
def get_basic_blocks(self, f):
raise NotImplementedError("ElfFeatureExtractor can only be used to extract file features")
def extract_basic_block_features(self, f, bb):
raise NotImplementedError("ElfFeatureExtractor can only be used to extract file features")
def get_instructions(self, f, bb):
raise NotImplementedError("ElfFeatureExtractor can only be used to extract file features")
def extract_insn_features(self, f, bb, insn):
raise NotImplementedError("ElfFeatureExtractor can only be used to extract file features")
def is_library_function(self, addr):
raise NotImplementedError("ElfFeatureExtractor can only be used to extract file features")
def get_function_name(self, addr):
raise NotImplementedError("ElfFeatureExtractor can only be used to extract file features")

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@@ -1,152 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import string
import struct
from typing import Tuple, Iterator
import ghidra
from ghidra.program.model.lang import OperandType
import capa.features.extractors.ghidra.helpers
from capa.features.common import Feature, Characteristic
from capa.features.address import Address
from capa.features.basicblock import BasicBlock
from capa.features.extractors.helpers import MIN_STACKSTRING_LEN
from capa.features.extractors.base_extractor import BBHandle, FunctionHandle
def get_printable_len(op: ghidra.program.model.scalar.Scalar) -> int:
"""Return string length if all operand bytes are ascii or utf16-le printable"""
op_bit_len = op.bitLength()
op_byte_len = op_bit_len // 8
op_val = op.getValue()
if op_bit_len == 8:
chars = struct.pack("<B", op_val & 0xFF)
elif op_bit_len == 16:
chars = struct.pack("<H", op_val & 0xFFFF)
elif op_bit_len == 32:
chars = struct.pack("<I", op_val & 0xFFFFFFFF)
elif op_bit_len == 64:
chars = struct.pack("<Q", op_val & 0xFFFFFFFFFFFFFFFF)
else:
raise ValueError(f"Unhandled operand data type 0x{op_bit_len:x}.")
def is_printable_ascii(chars_: bytes):
return all(c < 127 and chr(c) in string.printable for c in chars_)
def is_printable_utf16le(chars_: bytes):
if all(c == 0x00 for c in chars_[1::2]):
return is_printable_ascii(chars_[::2])
if is_printable_ascii(chars):
return op_byte_len
if is_printable_utf16le(chars):
return op_byte_len
return 0
def is_mov_imm_to_stack(insn: ghidra.program.database.code.InstructionDB) -> bool:
"""verify instruction moves immediate onto stack"""
# Ghidra will Bitwise OR the OperandTypes to assign multiple
# i.e., the first operand is a stackvar (dynamically allocated),
# and the second is a scalar value (single int/char/float/etc.)
mov_its_ops = [(OperandType.ADDRESS | OperandType.DYNAMIC), OperandType.SCALAR]
found = False
# MOV dword ptr [EBP + local_*], 0x65
if insn.getMnemonicString().startswith("MOV"):
found = all(insn.getOperandType(i) == mov_its_ops[i] for i in range(2))
return found
def bb_contains_stackstring(bb: ghidra.program.model.block.CodeBlock) -> bool:
"""check basic block for stackstring indicators
true if basic block contains enough moves of constant bytes to the stack
"""
count = 0
for insn in currentProgram().getListing().getInstructions(bb, True): # type: ignore [name-defined] # noqa: F821
if is_mov_imm_to_stack(insn):
count += get_printable_len(insn.getScalar(1))
if count > MIN_STACKSTRING_LEN:
return True
return False
def _bb_has_tight_loop(bb: ghidra.program.model.block.CodeBlock):
"""
parse tight loops, true if last instruction in basic block branches to bb start
"""
# Reverse Ordered, first InstructionDB
last_insn = currentProgram().getListing().getInstructions(bb, False).next() # type: ignore [name-defined] # noqa: F821
if last_insn.getFlowType().isJump():
return last_insn.getAddress(0) == bb.getMinAddress()
return False
def extract_bb_stackstring(fh: FunctionHandle, bbh: BBHandle) -> Iterator[Tuple[Feature, Address]]:
"""extract stackstring indicators from basic block"""
bb: ghidra.program.model.block.CodeBlock = bbh.inner
if bb_contains_stackstring(bb):
yield Characteristic("stack string"), bbh.address
def extract_bb_tight_loop(fh: FunctionHandle, bbh: BBHandle) -> Iterator[Tuple[Feature, Address]]:
"""check basic block for tight loop indicators"""
bb: ghidra.program.model.block.CodeBlock = bbh.inner
if _bb_has_tight_loop(bb):
yield Characteristic("tight loop"), bbh.address
BASIC_BLOCK_HANDLERS = (
extract_bb_tight_loop,
extract_bb_stackstring,
)
def extract_features(fh: FunctionHandle, bbh: BBHandle) -> Iterator[Tuple[Feature, Address]]:
"""
extract features from the given basic block.
args:
bb: the basic block to process.
yields:
Tuple[Feature, int]: the features and their location found in this basic block.
"""
yield BasicBlock(), bbh.address
for bb_handler in BASIC_BLOCK_HANDLERS:
for feature, addr in bb_handler(fh, bbh):
yield feature, addr
def main():
features = []
from capa.features.extractors.ghidra.extractor import GhidraFeatureExtractor
for fh in GhidraFeatureExtractor().get_functions():
for bbh in capa.features.extractors.ghidra.helpers.get_function_blocks(fh):
features.extend(list(extract_features(fh, bbh)))
import pprint
pprint.pprint(features) # noqa: T203
if __name__ == "__main__":
main()

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@@ -1,93 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import List, Tuple, Iterator
import capa.features.extractors.ghidra.file
import capa.features.extractors.ghidra.insn
import capa.features.extractors.ghidra.global_
import capa.features.extractors.ghidra.function
import capa.features.extractors.ghidra.basicblock
from capa.features.common import Feature
from capa.features.address import Address, AbsoluteVirtualAddress
from capa.features.extractors.base_extractor import (
BBHandle,
InsnHandle,
SampleHashes,
FunctionHandle,
StaticFeatureExtractor,
)
class GhidraFeatureExtractor(StaticFeatureExtractor):
def __init__(self):
import capa.features.extractors.ghidra.helpers as ghidra_helpers
super().__init__(
SampleHashes(
md5=capa.ghidra.helpers.get_file_md5(),
# ghidra doesn't expose this hash.
# https://ghidra.re/ghidra_docs/api/ghidra/program/model/listing/Program.html
#
# the hashes are stored in the database, not computed on the fly,
# so its probably not trivial to add SHA1.
sha1="",
sha256=capa.ghidra.helpers.get_file_sha256(),
)
)
self.global_features: List[Tuple[Feature, Address]] = []
self.global_features.extend(capa.features.extractors.ghidra.file.extract_file_format())
self.global_features.extend(capa.features.extractors.ghidra.global_.extract_os())
self.global_features.extend(capa.features.extractors.ghidra.global_.extract_arch())
self.imports = ghidra_helpers.get_file_imports()
self.externs = ghidra_helpers.get_file_externs()
self.fakes = ghidra_helpers.map_fake_import_addrs()
def get_base_address(self):
return AbsoluteVirtualAddress(currentProgram().getImageBase().getOffset()) # type: ignore [name-defined] # noqa: F821
def extract_global_features(self):
yield from self.global_features
def extract_file_features(self):
yield from capa.features.extractors.ghidra.file.extract_features()
def get_functions(self) -> Iterator[FunctionHandle]:
import capa.features.extractors.ghidra.helpers as ghidra_helpers
for fhandle in ghidra_helpers.get_function_symbols():
fh: FunctionHandle = FunctionHandle(
address=AbsoluteVirtualAddress(fhandle.getEntryPoint().getOffset()),
inner=fhandle,
ctx={"imports_cache": self.imports, "externs_cache": self.externs, "fakes_cache": self.fakes},
)
yield fh
@staticmethod
def get_function(addr: int) -> FunctionHandle:
func = getFunctionContaining(toAddr(addr)) # type: ignore [name-defined] # noqa: F821
return FunctionHandle(address=AbsoluteVirtualAddress(func.getEntryPoint().getOffset()), inner=func)
def extract_function_features(self, fh: FunctionHandle) -> Iterator[Tuple[Feature, Address]]:
yield from capa.features.extractors.ghidra.function.extract_features(fh)
def get_basic_blocks(self, fh: FunctionHandle) -> Iterator[BBHandle]:
import capa.features.extractors.ghidra.helpers as ghidra_helpers
yield from ghidra_helpers.get_function_blocks(fh)
def extract_basic_block_features(self, fh: FunctionHandle, bbh: BBHandle) -> Iterator[Tuple[Feature, Address]]:
yield from capa.features.extractors.ghidra.basicblock.extract_features(fh, bbh)
def get_instructions(self, fh: FunctionHandle, bbh: BBHandle) -> Iterator[InsnHandle]:
import capa.features.extractors.ghidra.helpers as ghidra_helpers
yield from ghidra_helpers.get_insn_in_range(bbh)
def extract_insn_features(self, fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle):
yield from capa.features.extractors.ghidra.insn.extract_features(fh, bbh, ih)

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@@ -1,204 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import re
import struct
from typing import List, Tuple, Iterator
from ghidra.program.model.symbol import SourceType, SymbolType
import capa.features.extractors.common
import capa.features.extractors.helpers
import capa.features.extractors.strings
import capa.features.extractors.ghidra.helpers
from capa.features.file import Export, Import, Section, FunctionName
from capa.features.common import FORMAT_PE, FORMAT_ELF, Format, String, Feature, Characteristic
from capa.features.address import NO_ADDRESS, Address, FileOffsetAddress, AbsoluteVirtualAddress
MAX_OFFSET_PE_AFTER_MZ = 0x200
def find_embedded_pe(block_bytez: bytes, mz_xor: List[Tuple[bytes, bytes, int]]) -> Iterator[Tuple[int, int]]:
"""check segment for embedded PE
adapted for Ghidra from:
https://github.com/vivisect/vivisect/blob/91e8419a861f4977https://github.com/vivisect/vivisect/blob/91e8419a861f49779f18316f155311967e696836/PE/carve.py#L259f18316f155311967e696836/PE/carve.py#L25
"""
todo = []
for mzx, pex, i in mz_xor:
for match in re.finditer(re.escape(mzx), block_bytez):
todo.append((match.start(), mzx, pex, i))
seg_max = len(block_bytez) # noqa: F821
while len(todo):
off, mzx, pex, i = todo.pop()
# MZ header has one field we will check e_lfanew is at 0x3c
e_lfanew = off + 0x3C
if seg_max < e_lfanew + 4:
continue
e_lfanew_bytes = block_bytez[e_lfanew : e_lfanew + 4]
newoff = struct.unpack("<I", capa.features.extractors.helpers.xor_static(e_lfanew_bytes, i))[0]
# assume XOR'd "PE" bytes exist within threshold
if newoff > MAX_OFFSET_PE_AFTER_MZ:
continue
peoff = off + newoff
if seg_max < peoff + 2:
continue
pe_bytes = block_bytez[peoff : peoff + 2]
if pe_bytes == pex:
yield off, i
def extract_file_embedded_pe() -> Iterator[Tuple[Feature, Address]]:
"""extract embedded PE features"""
# pre-compute XOR pairs
mz_xor: List[Tuple[bytes, bytes, int]] = [
(
capa.features.extractors.helpers.xor_static(b"MZ", i),
capa.features.extractors.helpers.xor_static(b"PE", i),
i,
)
for i in range(256)
]
for block in currentProgram().getMemory().getBlocks(): # type: ignore [name-defined] # noqa: F821
if not all((block.isLoaded(), block.isInitialized(), "Headers" not in block.getName())):
continue
for off, _ in find_embedded_pe(capa.features.extractors.ghidra.helpers.get_block_bytes(block), mz_xor):
# add offset back to block start
ea: int = block.getStart().add(off).getOffset()
yield Characteristic("embedded pe"), FileOffsetAddress(ea)
def extract_file_export_names() -> Iterator[Tuple[Feature, Address]]:
"""extract function exports"""
st = currentProgram().getSymbolTable() # type: ignore [name-defined] # noqa: F821
for addr in st.getExternalEntryPointIterator():
yield Export(st.getPrimarySymbol(addr).getName()), AbsoluteVirtualAddress(addr.getOffset())
def extract_file_import_names() -> Iterator[Tuple[Feature, Address]]:
"""extract function imports
1. imports by ordinal:
- modulename.#ordinal
2. imports by name, results in two features to support importname-only
matching:
- modulename.importname
- importname
"""
for f in currentProgram().getFunctionManager().getExternalFunctions(): # type: ignore [name-defined] # noqa: F821
for r in f.getSymbol().getReferences():
if r.getReferenceType().isData():
addr = r.getFromAddress().getOffset() # gets pointer to fake external addr
fstr = f.toString().split("::") # format: MODULE.dll::import / MODULE::Ordinal_*
if "Ordinal_" in fstr[1]:
fstr[1] = f"#{fstr[1].split('_')[1]}"
for name in capa.features.extractors.helpers.generate_symbols(fstr[0][:-4], fstr[1], include_dll=True):
yield Import(name), AbsoluteVirtualAddress(addr)
def extract_file_section_names() -> Iterator[Tuple[Feature, Address]]:
"""extract section names"""
for block in currentProgram().getMemory().getBlocks(): # type: ignore [name-defined] # noqa: F821
yield Section(block.getName()), AbsoluteVirtualAddress(block.getStart().getOffset())
def extract_file_strings() -> Iterator[Tuple[Feature, Address]]:
"""extract ASCII and UTF-16 LE strings"""
for block in currentProgram().getMemory().getBlocks(): # type: ignore [name-defined] # noqa: F821
if not block.isInitialized():
continue
p_bytes = capa.features.extractors.ghidra.helpers.get_block_bytes(block)
for s in capa.features.extractors.strings.extract_ascii_strings(p_bytes):
offset = block.getStart().getOffset() + s.offset
yield String(s.s), FileOffsetAddress(offset)
for s in capa.features.extractors.strings.extract_unicode_strings(p_bytes):
offset = block.getStart().getOffset() + s.offset
yield String(s.s), FileOffsetAddress(offset)
def extract_file_function_names() -> Iterator[Tuple[Feature, Address]]:
"""
extract the names of statically-linked library functions.
"""
for sym in currentProgram().getSymbolTable().getAllSymbols(True): # type: ignore [name-defined] # noqa: F821
# .isExternal() misses more than this config for the function symbols
if sym.getSymbolType() == SymbolType.FUNCTION and sym.getSource() == SourceType.ANALYSIS and sym.isGlobal():
name = sym.getName() # starts to resolve names based on Ghidra's FidDB
if name.startswith("FID_conflict:"): # format: FID_conflict:<function-name>
name = name[13:]
addr = AbsoluteVirtualAddress(sym.getAddress().getOffset())
yield FunctionName(name), addr
if name.startswith("_"):
# some linkers may prefix linked routines with a `_` to avoid name collisions.
# extract features for both the mangled and un-mangled representations.
# e.g. `_fwrite` -> `fwrite`
# see: https://stackoverflow.com/a/2628384/87207
yield FunctionName(name[1:]), addr
def extract_file_format() -> Iterator[Tuple[Feature, Address]]:
ef = currentProgram().getExecutableFormat() # type: ignore [name-defined] # noqa: F821
if "PE" in ef:
yield Format(FORMAT_PE), NO_ADDRESS
elif "ELF" in ef:
yield Format(FORMAT_ELF), NO_ADDRESS
elif "Raw" in ef:
# no file type to return when processing a binary file, but we want to continue processing
return
else:
raise NotImplementedError(f"unexpected file format: {ef}")
def extract_features() -> Iterator[Tuple[Feature, Address]]:
"""extract file features"""
for file_handler in FILE_HANDLERS:
for feature, addr in file_handler():
yield feature, addr
FILE_HANDLERS = (
extract_file_embedded_pe,
extract_file_export_names,
extract_file_import_names,
extract_file_section_names,
extract_file_strings,
extract_file_function_names,
extract_file_format,
)
def main():
""" """
import pprint
pprint.pprint(list(extract_features())) # noqa: T203
if __name__ == "__main__":
main()

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@@ -1,73 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import Tuple, Iterator
import ghidra
from ghidra.program.model.block import BasicBlockModel, SimpleBlockIterator
import capa.features.extractors.ghidra.helpers
from capa.features.common import Feature, Characteristic
from capa.features.address import Address, AbsoluteVirtualAddress
from capa.features.extractors import loops
from capa.features.extractors.base_extractor import FunctionHandle
def extract_function_calls_to(fh: FunctionHandle):
"""extract callers to a function"""
f: ghidra.program.database.function.FunctionDB = fh.inner
for ref in f.getSymbol().getReferences():
if ref.getReferenceType().isCall():
yield Characteristic("calls to"), AbsoluteVirtualAddress(ref.getFromAddress().getOffset())
def extract_function_loop(fh: FunctionHandle):
f: ghidra.program.database.function.FunctionDB = fh.inner
edges = []
for block in SimpleBlockIterator(BasicBlockModel(currentProgram()), f.getBody(), monitor()): # type: ignore [name-defined] # noqa: F821
dests = block.getDestinations(monitor()) # type: ignore [name-defined] # noqa: F821
s_addrs = block.getStartAddresses()
while dests.hasNext(): # For loop throws Python TypeError
for addr in s_addrs:
edges.append((addr.getOffset(), dests.next().getDestinationAddress().getOffset()))
if loops.has_loop(edges):
yield Characteristic("loop"), AbsoluteVirtualAddress(f.getEntryPoint().getOffset())
def extract_recursive_call(fh: FunctionHandle):
f: ghidra.program.database.function.FunctionDB = fh.inner
for func in f.getCalledFunctions(monitor()): # type: ignore [name-defined] # noqa: F821
if func.getEntryPoint().getOffset() == f.getEntryPoint().getOffset():
yield Characteristic("recursive call"), AbsoluteVirtualAddress(f.getEntryPoint().getOffset())
def extract_features(fh: FunctionHandle) -> Iterator[Tuple[Feature, Address]]:
for func_handler in FUNCTION_HANDLERS:
for feature, addr in func_handler(fh):
yield feature, addr
FUNCTION_HANDLERS = (extract_function_calls_to, extract_function_loop, extract_recursive_call)
def main():
""" """
features = []
for fhandle in capa.features.extractors.ghidra.helpers.get_function_symbols():
features.extend(list(extract_features(fhandle)))
import pprint
pprint.pprint(features) # noqa: T203
if __name__ == "__main__":
main()

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@@ -1,67 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
import contextlib
from typing import Tuple, Iterator
import capa.ghidra.helpers
import capa.features.extractors.elf
import capa.features.extractors.ghidra.helpers
from capa.features.common import OS, ARCH_I386, ARCH_AMD64, OS_WINDOWS, Arch, Feature
from capa.features.address import NO_ADDRESS, Address
logger = logging.getLogger(__name__)
def extract_os() -> Iterator[Tuple[Feature, Address]]:
format_name: str = currentProgram().getExecutableFormat() # type: ignore [name-defined] # noqa: F821
if "PE" in format_name:
yield OS(OS_WINDOWS), NO_ADDRESS
elif "ELF" in format_name:
with contextlib.closing(capa.ghidra.helpers.GHIDRAIO()) as f:
os = capa.features.extractors.elf.detect_elf_os(f)
yield OS(os), NO_ADDRESS
else:
# we likely end up here:
# 1. handling shellcode, or
# 2. handling a new file format (e.g. macho)
#
# for (1) we can't do much - its shellcode and all bets are off.
# we could maybe accept a further CLI argument to specify the OS,
# but i think this would be rarely used.
# rules that rely on OS conditions will fail to match on shellcode.
#
# for (2), this logic will need to be updated as the format is implemented.
logger.debug("unsupported file format: %s, will not guess OS", format_name)
return
def extract_arch() -> Iterator[Tuple[Feature, Address]]:
lang_id = currentProgram().getMetadata().get("Language ID") # type: ignore [name-defined] # noqa: F821
if "x86" in lang_id and "64" in lang_id:
yield Arch(ARCH_AMD64), NO_ADDRESS
elif "x86" in lang_id and "32" in lang_id:
yield Arch(ARCH_I386), NO_ADDRESS
elif "x86" not in lang_id:
logger.debug("unsupported architecture: non-32-bit nor non-64-bit intel")
return
else:
# we likely end up here:
# 1. handling a new architecture (e.g. aarch64)
#
# for (1), this logic will need to be updated as the format is implemented.
logger.debug("unsupported architecture: %s", lang_id)
return

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@@ -1,301 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import Dict, List, Iterator
import ghidra
import java.lang
from ghidra.program.model.lang import OperandType
from ghidra.program.model.block import BasicBlockModel, SimpleBlockIterator
from ghidra.program.model.symbol import SourceType, SymbolType
from ghidra.program.model.address import AddressSpace
import capa.features.extractors.helpers
from capa.features.common import THUNK_CHAIN_DEPTH_DELTA
from capa.features.address import AbsoluteVirtualAddress
from capa.features.extractors.base_extractor import BBHandle, InsnHandle, FunctionHandle
def ints_to_bytes(bytez: List[int]) -> bytes:
"""convert Java signed ints to Python bytes
args:
bytez: list of Java signed ints
"""
return bytes([b & 0xFF for b in bytez])
def find_byte_sequence(addr: ghidra.program.model.address.Address, seq: bytes) -> Iterator[int]:
"""yield all ea of a given byte sequence
args:
addr: start address
seq: bytes to search e.g. b"\x01\x03"
"""
seqstr = "".join([f"\\x{b:02x}" for b in seq])
eas = findBytes(addr, seqstr, java.lang.Integer.MAX_VALUE, 1) # type: ignore [name-defined] # noqa: F821
yield from eas
def get_bytes(addr: ghidra.program.model.address.Address, length: int) -> bytes:
"""yield length bytes at addr
args:
addr: Address to begin pull from
length: length of bytes to pull
"""
try:
return ints_to_bytes(getBytes(addr, length)) # type: ignore [name-defined] # noqa: F821
except RuntimeError:
return b""
def get_block_bytes(block: ghidra.program.model.mem.MemoryBlock) -> bytes:
"""yield all bytes in a given block
args:
block: MemoryBlock to pull from
"""
return get_bytes(block.getStart(), block.getSize())
def get_function_symbols():
"""yield all non-external function symbols"""
yield from currentProgram().getFunctionManager().getFunctionsNoStubs(True) # type: ignore [name-defined] # noqa: F821
def get_function_blocks(fh: FunctionHandle) -> Iterator[BBHandle]:
"""yield BBHandle for each bb in a given function"""
func: ghidra.program.database.function.FunctionDB = fh.inner
for bb in SimpleBlockIterator(BasicBlockModel(currentProgram()), func.getBody(), monitor()): # type: ignore [name-defined] # noqa: F821
yield BBHandle(address=AbsoluteVirtualAddress(bb.getMinAddress().getOffset()), inner=bb)
def get_insn_in_range(bbh: BBHandle) -> Iterator[InsnHandle]:
"""yield InshHandle for each insn in a given basicblock"""
for insn in currentProgram().getListing().getInstructions(bbh.inner, True): # type: ignore [name-defined] # noqa: F821
yield InsnHandle(address=AbsoluteVirtualAddress(insn.getAddress().getOffset()), inner=insn)
def get_file_imports() -> Dict[int, List[str]]:
"""get all import names & addrs"""
import_dict: Dict[int, List[str]] = {}
for f in currentProgram().getFunctionManager().getExternalFunctions(): # type: ignore [name-defined] # noqa: F821
for r in f.getSymbol().getReferences():
if r.getReferenceType().isData():
addr = r.getFromAddress().getOffset() # gets pointer to fake external addr
ex_loc = f.getExternalLocation().getAddress() # map external locations as well (offset into module files)
fstr = f.toString().split("::") # format: MODULE.dll::import / MODULE::Ordinal_* / <EXTERNAL>::import
if "Ordinal_" in fstr[1]:
fstr[1] = f"#{fstr[1].split('_')[1]}"
# <EXTERNAL> mostly shows up in ELF files, otherwise, strip '.dll' w/ [:-4]
fstr[0] = "*" if "<EXTERNAL>" in fstr[0] else fstr[0][:-4]
for name in capa.features.extractors.helpers.generate_symbols(fstr[0], fstr[1]):
import_dict.setdefault(addr, []).append(name)
if ex_loc:
import_dict.setdefault(ex_loc.getOffset(), []).append(name)
return import_dict
def get_file_externs() -> Dict[int, List[str]]:
"""
Gets function names & addresses of statically-linked library functions
Ghidra's external namespace is mostly reserved for dynamically-linked
imports. Statically-linked functions are part of the global namespace.
Filtering on the type, source, and namespace of the symbols yield more
statically-linked library functions.
Example: (PMA Lab 16-01.exe_) 7faafc7e4a5c736ebfee6abbbc812d80:0x407490
- __aulldiv
- Note: See Symbol Table labels
"""
extern_dict: Dict[int, List[str]] = {}
for sym in currentProgram().getSymbolTable().getAllSymbols(True): # type: ignore [name-defined] # noqa: F821
# .isExternal() misses more than this config for the function symbols
if sym.getSymbolType() == SymbolType.FUNCTION and sym.getSource() == SourceType.ANALYSIS and sym.isGlobal():
name = sym.getName() # starts to resolve names based on Ghidra's FidDB
if name.startswith("FID_conflict:"): # format: FID_conflict:<function-name>
name = name[13:]
extern_dict.setdefault(sym.getAddress().getOffset(), []).append(name)
if name.startswith("_"):
# some linkers may prefix linked routines with a `_` to avoid name collisions.
# extract features for both the mangled and un-mangled representations.
# e.g. `_fwrite` -> `fwrite`
# see: https://stackoverflow.com/a/2628384/87207
extern_dict.setdefault(sym.getAddress().getOffset(), []).append(name[1:])
return extern_dict
def map_fake_import_addrs() -> Dict[int, List[int]]:
"""
Map ghidra's fake import entrypoints to their
real addresses
Helps as many Ghidra Scripting API calls end up returning
these external (fake) addresses.
Undocumented but intended Ghidra behavior:
- Import entryPoint fields are stored in the 'EXTERNAL:' AddressSpace.
'getEntryPoint()' returns the entryPoint field, which is an offset
from the beginning of the assigned AddressSpace. In the case of externals,
they start from 1 and increment.
https://github.com/NationalSecurityAgency/ghidra/blob/26d4bd9104809747c21f2528cab8aba9aef9acd5/Ghidra/Features/Base/src/test.slow/java/ghidra/program/database/function/ExternalFunctionDBTest.java#L90
Example: (mimikatz.exe_) 5f66b82558ca92e54e77f216ef4c066c:0x473090
- 0x473090 -> PTR_CreateServiceW_00473090
- 'EXTERNAL:00000025' -> External Address (ghidra.program.model.address.SpecialAddress)
"""
fake_dict: Dict[int, List[int]] = {}
for f in currentProgram().getFunctionManager().getExternalFunctions(): # type: ignore [name-defined] # noqa: F821
for r in f.getSymbol().getReferences():
if r.getReferenceType().isData():
fake_dict.setdefault(f.getEntryPoint().getOffset(), []).append(r.getFromAddress().getOffset())
return fake_dict
def check_addr_for_api(
addr: ghidra.program.model.address.Address,
fakes: Dict[int, List[int]],
imports: Dict[int, List[str]],
externs: Dict[int, List[str]],
) -> bool:
offset = addr.getOffset()
fake = fakes.get(offset)
if fake:
return True
imp = imports.get(offset)
if imp:
return True
extern = externs.get(offset)
if extern:
return True
return False
def is_call_or_jmp(insn: ghidra.program.database.code.InstructionDB) -> bool:
return any(mnem in insn.getMnemonicString() for mnem in ["CALL", "J"]) # JMP, JNE, JNZ, etc
def is_sp_modified(insn: ghidra.program.database.code.InstructionDB) -> bool:
for i in range(insn.getNumOperands()):
if insn.getOperandType(i) == OperandType.REGISTER:
return "SP" in insn.getRegister(i).getName() and insn.getOperandRefType(i).isWrite()
return False
def is_stack_referenced(insn: ghidra.program.database.code.InstructionDB) -> bool:
"""generic catch-all for stack references"""
for i in range(insn.getNumOperands()):
if insn.getOperandType(i) == OperandType.REGISTER:
if "BP" in insn.getRegister(i).getName():
return True
else:
continue
return any(ref.isStackReference() for ref in insn.getReferencesFrom())
def is_zxor(insn: ghidra.program.database.code.InstructionDB) -> bool:
# assume XOR insn
# XOR's against the same operand zero out
ops = []
operands = []
for i in range(insn.getNumOperands()):
ops.append(insn.getOpObjects(i))
# Operands stored in a 2D array
for j in range(len(ops)):
for k in range(len(ops[j])):
operands.append(ops[j][k])
return all(n == operands[0] for n in operands)
def handle_thunk(addr: ghidra.program.model.address.Address):
"""Follow thunk chains down to a reasonable depth"""
ref = addr
for _ in range(THUNK_CHAIN_DEPTH_DELTA):
thunk_jmp = getInstructionAt(ref) # type: ignore [name-defined] # noqa: F821
if thunk_jmp and is_call_or_jmp(thunk_jmp):
if OperandType.isAddress(thunk_jmp.getOperandType(0)):
ref = thunk_jmp.getAddress(0)
else:
thunk_dat = getDataContaining(ref) # type: ignore [name-defined] # noqa: F821
if thunk_dat and thunk_dat.isDefined() and thunk_dat.isPointer():
ref = thunk_dat.getValue()
break # end of thunk chain reached
return ref
def dereference_ptr(insn: ghidra.program.database.code.InstructionDB):
addr_code = OperandType.ADDRESS | OperandType.CODE
to_deref = insn.getAddress(0)
dat = getDataContaining(to_deref) # type: ignore [name-defined] # noqa: F821
if insn.getOperandType(0) == addr_code:
thfunc = getFunctionContaining(to_deref) # type: ignore [name-defined] # noqa: F821
if thfunc and thfunc.isThunk():
return handle_thunk(to_deref)
else:
# if it doesn't poin to a thunk, it's usually a jmp to a label
return to_deref
if not dat:
return to_deref
if dat.isDefined() and dat.isPointer():
addr = dat.getValue()
# now we need to check the addr space to see if it is truly resolvable
# ghidra sometimes likes to hand us direct RAM addrs, which typically point
# to api calls that we can't actually resolve as such
if addr.getAddressSpace().getType() == AddressSpace.TYPE_RAM:
return to_deref
else:
return addr
else:
return to_deref
def find_data_references_from_insn(insn, max_depth: int = 10):
"""yield data references from given instruction"""
for reference in insn.getReferencesFrom():
if not reference.getReferenceType().isData():
# only care about data references
continue
to_addr = reference.getToAddress()
for _ in range(max_depth - 1):
data = getDataAt(to_addr) # type: ignore [name-defined] # noqa: F821
if data and data.isPointer():
ptr_value = data.getValue()
if ptr_value is None:
break
to_addr = ptr_value
else:
break
yield to_addr

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@@ -1,503 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import Any, Dict, Tuple, Iterator
import ghidra
from ghidra.program.model.lang import OperandType
from ghidra.program.model.block import SimpleBlockModel
import capa.features.extractors.helpers
import capa.features.extractors.ghidra.helpers
from capa.features.insn import API, MAX_STRUCTURE_SIZE, Number, Offset, Mnemonic, OperandNumber, OperandOffset
from capa.features.common import MAX_BYTES_FEATURE_SIZE, Bytes, String, Feature, Characteristic
from capa.features.address import Address, AbsoluteVirtualAddress
from capa.features.extractors.base_extractor import BBHandle, InsnHandle, FunctionHandle
# security cookie checks may perform non-zeroing XORs, these are expected within a certain
# byte range within the first and returning basic blocks, this helps to reduce FP features
SECURITY_COOKIE_BYTES_DELTA = 0x40
OPERAND_TYPE_DYNAMIC_ADDRESS = OperandType.DYNAMIC | OperandType.ADDRESS
def get_imports(ctx: Dict[str, Any]) -> Dict[int, Any]:
"""Populate the import cache for this context"""
if "imports_cache" not in ctx:
ctx["imports_cache"] = capa.features.extractors.ghidra.helpers.get_file_imports()
return ctx["imports_cache"]
def get_externs(ctx: Dict[str, Any]) -> Dict[int, Any]:
"""Populate the externs cache for this context"""
if "externs_cache" not in ctx:
ctx["externs_cache"] = capa.features.extractors.ghidra.helpers.get_file_externs()
return ctx["externs_cache"]
def get_fakes(ctx: Dict[str, Any]) -> Dict[int, Any]:
"""Populate the fake import addrs cache for this context"""
if "fakes_cache" not in ctx:
ctx["fakes_cache"] = capa.features.extractors.ghidra.helpers.map_fake_import_addrs()
return ctx["fakes_cache"]
def check_for_api_call(
insn, externs: Dict[int, Any], fakes: Dict[int, Any], imports: Dict[int, Any], imp_or_ex: bool
) -> Iterator[Any]:
"""check instruction for API call
params:
externs - external library functions cache
fakes - mapped fake import addresses cache
imports - imported functions cache
imp_or_ex - flag to check imports or externs
yields:
matched api calls
"""
info = ()
funcs = imports if imp_or_ex else externs
# assume only CALLs or JMPs are passed
ref_type = insn.getOperandType(0)
addr_data = OperandType.ADDRESS | OperandType.DATA # needs dereferencing
addr_code = OperandType.ADDRESS | OperandType.CODE # needs dereferencing
if OperandType.isRegister(ref_type):
if OperandType.isAddress(ref_type):
# If it's an address in a register, check the mapped fake addrs
# since they're dereferenced to their fake addrs
op_ref = insn.getAddress(0).getOffset()
ref = fakes.get(op_ref) # obtain the real addr
if not ref:
return
else:
return
elif ref_type in (addr_data, addr_code) or (OperandType.isIndirect(ref_type) and OperandType.isAddress(ref_type)):
# we must dereference and check if the addr is a pointer to an api function
addr_ref = capa.features.extractors.ghidra.helpers.dereference_ptr(insn)
if not capa.features.extractors.ghidra.helpers.check_addr_for_api(addr_ref, fakes, imports, externs):
return
ref = addr_ref.getOffset()
elif ref_type == OPERAND_TYPE_DYNAMIC_ADDRESS or ref_type == OperandType.DYNAMIC:
return # cannot resolve dynamics statically
else:
# pure address does not need to get dereferenced/ handled
addr_ref = insn.getAddress(0)
if not addr_ref:
# If it returned null, it was an indirect
# that had no address reference.
# This check is faster than checking for (indirect and not address)
return
if not capa.features.extractors.ghidra.helpers.check_addr_for_api(addr_ref, fakes, imports, externs):
return
ref = addr_ref.getOffset()
if isinstance(ref, list): # ref from REG | ADDR
for r in ref:
info = funcs.get(r) # type: ignore
if info:
yield info
else:
info = funcs.get(ref) # type: ignore
if info:
yield info
def extract_insn_api_features(fh: FunctionHandle, bb: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
insn: ghidra.program.database.code.InstructionDB = ih.inner
if not capa.features.extractors.ghidra.helpers.is_call_or_jmp(insn):
return
externs = get_externs(fh.ctx)
fakes = get_fakes(fh.ctx)
imports = get_imports(fh.ctx)
# check calls to imported functions
for api in check_for_api_call(insn, externs, fakes, imports, True):
for imp in api:
yield API(imp), ih.address
# check calls to extern functions
for api in check_for_api_call(insn, externs, fakes, imports, False):
for ext in api:
yield API(ext), ih.address
def extract_insn_number_features(fh: FunctionHandle, bb: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction number features
example:
push 3136B0h ; dwControlCode
"""
insn: ghidra.program.database.code.InstructionDB = ih.inner
if insn.getMnemonicString().startswith("RET"):
# skip things like:
# .text:0042250E retn 8
return
if capa.features.extractors.ghidra.helpers.is_sp_modified(insn):
# skip things like:
# .text:00401145 add esp, 0Ch
return
for i in range(insn.getNumOperands()):
# Exceptions for LEA insn:
# invalid operand encoding, considered numbers instead of offsets
# see: mimikatz.exe_:0x4018C0
if insn.getOperandType(i) == OperandType.DYNAMIC and insn.getMnemonicString().startswith("LEA"):
# Additional check, avoid yielding "wide" values (ex. mimikatz.exe:0x471EE6 LEA EBX, [ECX + EAX*0x4])
op_objs = insn.getOpObjects(i)
if len(op_objs) == 3: # ECX, EAX, 0x4
continue
if isinstance(op_objs[-1], ghidra.program.model.scalar.Scalar):
const = op_objs[-1].getUnsignedValue()
addr = ih.address
yield Number(const), addr
yield OperandNumber(i, const), addr
elif not OperandType.isScalar(insn.getOperandType(i)):
# skip things like:
# references, void types
continue
else:
const = insn.getScalar(i).getUnsignedValue()
addr = ih.address
yield Number(const), addr
yield OperandNumber(i, const), addr
if insn.getMnemonicString().startswith("ADD") and 0 < const < MAX_STRUCTURE_SIZE:
# for pattern like:
#
# add eax, 0x10
#
# assume 0x10 is also an offset (imagine eax is a pointer).
yield Offset(const), addr
yield OperandOffset(i, const), addr
def extract_insn_offset_features(fh: FunctionHandle, bb: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction structure offset features
example:
.text:0040112F cmp [esi+4], ebx
"""
insn: ghidra.program.database.code.InstructionDB = ih.inner
if insn.getMnemonicString().startswith("LEA"):
return
if capa.features.extractors.ghidra.helpers.is_stack_referenced(insn):
# ignore stack references
return
# Ghidra stores operands in 2D arrays if they contain offsets
for i in range(insn.getNumOperands()):
if insn.getOperandType(i) == OperandType.DYNAMIC: # e.g. [esi + 4]
# manual extraction, since the default api calls only work on the 1st dimension of the array
op_objs = insn.getOpObjects(i)
if not op_objs:
continue
if isinstance(op_objs[-1], ghidra.program.model.scalar.Scalar):
op_off = op_objs[-1].getValue()
else:
op_off = 0
yield Offset(op_off), ih.address
yield OperandOffset(i, op_off), ih.address
def extract_insn_bytes_features(fh: FunctionHandle, bb: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""
parse referenced byte sequences
example:
push offset iid_004118d4_IShellLinkA ; riid
"""
for addr in capa.features.extractors.ghidra.helpers.find_data_references_from_insn(ih.inner):
data = getDataAt(addr) # type: ignore [name-defined] # noqa: F821
if data and not data.hasStringValue():
extracted_bytes = capa.features.extractors.ghidra.helpers.get_bytes(addr, MAX_BYTES_FEATURE_SIZE)
if extracted_bytes and not capa.features.extractors.helpers.all_zeros(extracted_bytes):
yield Bytes(extracted_bytes), ih.address
def extract_insn_string_features(fh: FunctionHandle, bb: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction string features
example:
push offset aAcr ; "ACR > "
"""
for addr in capa.features.extractors.ghidra.helpers.find_data_references_from_insn(ih.inner):
data = getDataAt(addr) # type: ignore [name-defined] # noqa: F821
if data and data.hasStringValue():
yield String(data.getValue()), ih.address
def extract_insn_mnemonic_features(
fh: FunctionHandle, bb: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""parse instruction mnemonic features"""
insn: ghidra.program.database.code.InstructionDB = ih.inner
yield Mnemonic(insn.getMnemonicString().lower()), ih.address
def extract_insn_obfs_call_plus_5_characteristic_features(
fh: FunctionHandle, bb: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""
parse call $+5 instruction from the given instruction.
"""
insn: ghidra.program.database.code.InstructionDB = ih.inner
if not capa.features.extractors.ghidra.helpers.is_call_or_jmp(insn):
return
code_ref = OperandType.ADDRESS | OperandType.CODE
ref = insn.getAddress()
for i in range(insn.getNumOperands()):
if insn.getOperandType(i) == code_ref:
ref = insn.getAddress(i)
if insn.getAddress().add(5) == ref:
yield Characteristic("call $+5"), ih.address
def extract_insn_segment_access_features(
fh: FunctionHandle, bb: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""parse instruction fs or gs access"""
insn: ghidra.program.database.code.InstructionDB = ih.inner
insn_str = insn.toString()
if "FS:" in insn_str:
yield Characteristic("fs access"), ih.address
if "GS:" in insn_str:
yield Characteristic("gs access"), ih.address
def extract_insn_peb_access_characteristic_features(
fh: FunctionHandle, bb: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""parse instruction peb access
fs:[0x30] on x86, gs:[0x60] on x64
"""
insn: ghidra.program.database.code.InstructionDB = ih.inner
insn_str = insn.toString()
if insn_str.startswith(("PUSH", "MOV")):
if "FS:[0x30]" in insn_str or "GS:[0x60]" in insn_str:
yield Characteristic("peb access"), ih.address
def extract_insn_cross_section_cflow(
fh: FunctionHandle, bb: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""inspect the instruction for a CALL or JMP that crosses section boundaries"""
insn: ghidra.program.database.code.InstructionDB = ih.inner
if not capa.features.extractors.ghidra.helpers.is_call_or_jmp(insn):
return
externs = get_externs(fh.ctx)
fakes = get_fakes(fh.ctx)
imports = get_imports(fh.ctx)
# OperandType to dereference
addr_data = OperandType.ADDRESS | OperandType.DATA
addr_code = OperandType.ADDRESS | OperandType.CODE
ref_type = insn.getOperandType(0)
# both OperandType flags must be present
# bail on REGISTER alone
if OperandType.isRegister(ref_type):
if OperandType.isAddress(ref_type):
ref = insn.getAddress(0) # Ghidra dereferences REG | ADDR
if capa.features.extractors.ghidra.helpers.check_addr_for_api(ref, fakes, imports, externs):
return
else:
return
elif ref_type in (addr_data, addr_code) or (OperandType.isIndirect(ref_type) and OperandType.isAddress(ref_type)):
# we must dereference and check if the addr is a pointer to an api function
ref = capa.features.extractors.ghidra.helpers.dereference_ptr(insn)
if capa.features.extractors.ghidra.helpers.check_addr_for_api(ref, fakes, imports, externs):
return
elif ref_type == OPERAND_TYPE_DYNAMIC_ADDRESS or ref_type == OperandType.DYNAMIC:
return # cannot resolve dynamics statically
else:
# pure address does not need to get dereferenced/ handled
ref = insn.getAddress(0)
if not ref:
# If it returned null, it was an indirect
# that had no address reference.
# This check is faster than checking for (indirect and not address)
return
if capa.features.extractors.ghidra.helpers.check_addr_for_api(ref, fakes, imports, externs):
return
this_mem_block = getMemoryBlock(insn.getAddress()) # type: ignore [name-defined] # noqa: F821
ref_block = getMemoryBlock(ref) # type: ignore [name-defined] # noqa: F821
if ref_block != this_mem_block:
yield Characteristic("cross section flow"), ih.address
def extract_function_calls_from(
fh: FunctionHandle,
bb: BBHandle,
ih: InsnHandle,
) -> Iterator[Tuple[Feature, Address]]:
"""extract functions calls from features
most relevant at the function scope, however, its most efficient to extract at the instruction scope
"""
insn: ghidra.program.database.code.InstructionDB = ih.inner
if insn.getMnemonicString().startswith("CALL"):
# This method of "dereferencing" addresses/ pointers
# is not as robust as methods in other functions,
# but works just fine for this one
reference = 0
for ref in insn.getReferencesFrom():
addr = ref.getToAddress()
# avoid returning fake addrs
if not addr.isExternalAddress():
reference = addr.getOffset()
# if a reference is < 0, then ghidra pulled an offset from a DYNAMIC | ADDR (usually a stackvar)
# these cannot be resolved to actual addrs
if reference > 0:
yield Characteristic("calls from"), AbsoluteVirtualAddress(reference)
def extract_function_indirect_call_characteristic_features(
fh: FunctionHandle,
bb: BBHandle,
ih: InsnHandle,
) -> Iterator[Tuple[Feature, Address]]:
"""extract indirect function calls (e.g., call eax or call dword ptr [edx+4])
does not include calls like => call ds:dword_ABD4974
most relevant at the function or basic block scope;
however, its most efficient to extract at the instruction scope
"""
insn: ghidra.program.database.code.InstructionDB = ih.inner
if insn.getMnemonicString().startswith("CALL"):
if OperandType.isRegister(insn.getOperandType(0)):
yield Characteristic("indirect call"), ih.address
if OperandType.isIndirect(insn.getOperandType(0)):
yield Characteristic("indirect call"), ih.address
def check_nzxor_security_cookie_delta(
fh: ghidra.program.database.function.FunctionDB, insn: ghidra.program.database.code.InstructionDB
):
"""Get the function containing the insn
Get the last block of the function that contains the insn
Check the bb containing the insn
Check the last bb of the function containing the insn
"""
model = SimpleBlockModel(currentProgram()) # type: ignore [name-defined] # noqa: F821
insn_addr = insn.getAddress()
func_asv = fh.getBody()
first_addr = func_asv.getMinAddress()
last_addr = func_asv.getMaxAddress()
if model.getFirstCodeBlockContaining(
first_addr, monitor() # type: ignore [name-defined] # noqa: F821
) == model.getFirstCodeBlockContaining(
last_addr, monitor() # type: ignore [name-defined] # noqa: F821
):
if insn_addr < first_addr.add(SECURITY_COOKIE_BYTES_DELTA):
return True
else:
return insn_addr > last_addr.add(SECURITY_COOKIE_BYTES_DELTA * -1)
else:
return False
def extract_insn_nzxor_characteristic_features(
fh: FunctionHandle,
bb: BBHandle,
ih: InsnHandle,
) -> Iterator[Tuple[Feature, Address]]:
f: ghidra.program.database.function.FunctionDB = fh.inner
insn: ghidra.program.database.code.InstructionDB = ih.inner
if "XOR" not in insn.getMnemonicString():
return
if capa.features.extractors.ghidra.helpers.is_stack_referenced(insn):
return
if capa.features.extractors.ghidra.helpers.is_zxor(insn):
return
if check_nzxor_security_cookie_delta(f, insn):
return
yield Characteristic("nzxor"), ih.address
def extract_features(
fh: FunctionHandle,
bb: BBHandle,
insn: InsnHandle,
) -> Iterator[Tuple[Feature, Address]]:
for insn_handler in INSTRUCTION_HANDLERS:
for feature, addr in insn_handler(fh, bb, insn):
yield feature, addr
INSTRUCTION_HANDLERS = (
extract_insn_api_features,
extract_insn_number_features,
extract_insn_bytes_features,
extract_insn_string_features,
extract_insn_offset_features,
extract_insn_nzxor_characteristic_features,
extract_insn_mnemonic_features,
extract_insn_obfs_call_plus_5_characteristic_features,
extract_insn_peb_access_characteristic_features,
extract_insn_cross_section_cflow,
extract_insn_segment_access_features,
extract_function_calls_from,
extract_function_indirect_call_characteristic_features,
)
def main():
""" """
features = []
from capa.features.extractors.ghidra.extractor import GhidraFeatureExtractor
for fh in GhidraFeatureExtractor().get_functions():
for bb in capa.features.extractors.ghidra.helpers.get_function_blocks(fh):
for insn in capa.features.extractors.ghidra.helpers.get_insn_in_range(bb):
features.extend(list(extract_features(fh, bb, insn)))
import pprint
pprint.pprint(features) # noqa: T203
if __name__ == "__main__":
main()

View File

@@ -1,4 +1,4 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
@@ -6,18 +6,23 @@
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import struct
import sys
import builtins
from typing import Tuple, Iterator
from capa.features.file import Import
from capa.features.insn import API
MIN_STACKSTRING_LEN = 8
def xor_static(data: bytes, i: int) -> bytes:
return bytes(c ^ i for c in data)
def xor_static(data, i):
if sys.version_info >= (3, 0):
return bytes(c ^ i for c in data)
else:
return "".join(chr(ord(c) ^ i) for c in data)
def is_aw_function(symbol: str) -> bool:
def is_aw_function(symbol):
"""
is the given function name an A/W function?
these are variants of functions that, on Windows, accept either a narrow or wide string.
@@ -29,10 +34,11 @@ def is_aw_function(symbol: str) -> bool:
if symbol[-1] not in ("A", "W"):
return False
return True
# second to last character should be lowercase letter
return "a" <= symbol[-2] <= "z" or "0" <= symbol[-2] <= "9"
def is_ordinal(symbol: str) -> bool:
def is_ordinal(symbol):
"""
is the given symbol an ordinal that is prefixed by "#"?
"""
@@ -41,69 +47,37 @@ def is_ordinal(symbol: str) -> bool:
return False
def generate_symbols(dll: str, symbol: str, include_dll=False) -> Iterator[str]:
def generate_symbols(dll, symbol):
"""
for a given dll and symbol name, generate variants.
we over-generate features to make matching easier.
these include:
- CreateFileA
- CreateFile
- ws2_32.#1
note that since capa v7 only `import` features and APIs called via ordinal include DLL names:
- kernel32.CreateFileA
- kernel32.CreateFile
- ws2_32.#1
for `api` features dll names are good for documentation but not used during matching
- CreateFileA
- CreateFile
"""
# normalize dll name
dll = dll.lower()
# trim extensions observed in dynamic traces
dll = dll[0:-4] if dll.endswith(".dll") else dll
dll = dll[0:-4] if dll.endswith(".drv") else dll
if include_dll or is_ordinal(symbol):
# ws2_32.#1
# kernel32.CreateFileA
yield f"{dll}.{symbol}"
# kernel32.CreateFileA
yield "%s.%s" % (dll, symbol)
if not is_ordinal(symbol):
# CreateFileA
yield symbol
if is_aw_function(symbol):
if include_dll:
# kernel32.CreateFile
yield f"{dll}.{symbol[:-1]}"
if is_aw_function(symbol):
# kernel32.CreateFile
yield "%s.%s" % (dll, symbol[:-1])
if not is_ordinal(symbol):
# CreateFile
yield symbol[:-1]
def reformat_forwarded_export_name(forwarded_name: str) -> str:
"""
a forwarded export has a DLL name/path and symbol name.
we want the former to be lowercase, and the latter to be verbatim.
"""
# use rpartition so we can split on separator between dll and name.
# the dll name can be a full path, like in the case of
# ef64d6d7c34250af8e21a10feb931c9b
# which i assume means the path can have embedded periods.
# so we don't want the first period, we want the last.
forwarded_dll, _, forwarded_symbol = forwarded_name.rpartition(".")
forwarded_dll = forwarded_dll.lower()
return f"{forwarded_dll}.{forwarded_symbol}"
def all_zeros(bytez: bytes) -> bool:
def all_zeros(bytez):
return all(b == 0 for b in builtins.bytes(bytez))
def twos_complement(val: int, bits: int) -> int:
def twos_complement(val, bits):
"""
compute the 2's complement of int value val
@@ -116,48 +90,3 @@ def twos_complement(val: int, bits: int) -> int:
else:
# return positive value as is
return val
def carve_pe(pbytes: bytes, offset: int = 0) -> Iterator[Tuple[int, int]]:
"""
Generate (offset, key) tuples of embedded PEs
Based on the version from vivisect:
https://github.com/vivisect/vivisect/blob/7be4037b1cecc4551b397f840405a1fc606f9b53/PE/carve.py#L19
And its IDA adaptation:
capa/features/extractors/ida/file.py
"""
mz_xor = [
(
xor_static(b"MZ", key),
xor_static(b"PE", key),
key,
)
for key in range(256)
]
pblen = len(pbytes)
todo = [(pbytes.find(mzx, offset), mzx, pex, key) for mzx, pex, key in mz_xor]
todo = [(off, mzx, pex, key) for (off, mzx, pex, key) in todo if off != -1]
while len(todo):
off, mzx, pex, key = todo.pop()
# The MZ header has one field we will check
# e_lfanew is at 0x3c
e_lfanew = off + 0x3C
if pblen < (e_lfanew + 4):
continue
newoff = struct.unpack("<I", xor_static(pbytes[e_lfanew : e_lfanew + 4], key))[0]
nextres = pbytes.find(mzx, off + 1)
if nextres != -1:
todo.append((nextres, mzx, pex, key))
peoff = off + newoff
if pblen < (peoff + 2):
continue
if pbytes[peoff : peoff + 2] == pex:
yield (off, key)

View File

@@ -0,0 +1,93 @@
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import sys
import types
import idaapi
import capa.features.extractors.ida.file
import capa.features.extractors.ida.insn
import capa.features.extractors.ida.function
import capa.features.extractors.ida.basicblock
from capa.features.extractors import FeatureExtractor
def get_ea(self):
""" """
if isinstance(self, (idaapi.BasicBlock, idaapi.func_t)):
return self.start_ea
if isinstance(self, idaapi.insn_t):
return self.ea
raise TypeError
def add_ea_int_cast(o):
"""
dynamically add a cast-to-int (`__int__`) method to the given object
that returns the value of the `.ea` property.
this bit of skullduggery lets use cast viv-utils objects as ints.
the correct way of doing this is to update viv-utils (or subclass the objects here).
"""
if sys.version_info[0] >= 3:
setattr(o, "__int__", types.MethodType(get_ea, o))
else:
setattr(o, "__int__", types.MethodType(get_ea, o, type(o)))
return o
class IdaFeatureExtractor(FeatureExtractor):
def __init__(self):
super(IdaFeatureExtractor, self).__init__()
def get_base_address(self):
return idaapi.get_imagebase()
def extract_file_features(self):
for (feature, ea) in capa.features.extractors.ida.file.extract_features():
yield feature, ea
def get_functions(self):
import capa.features.extractors.ida.helpers as ida_helpers
# data structure shared across functions yielded here.
# useful for caching analysis relevant across a single workspace.
ctx = {}
# ignore library functions and thunk functions as identified by IDA
for f in ida_helpers.get_functions(skip_thunks=True, skip_libs=True):
setattr(f, "ctx", ctx)
yield add_ea_int_cast(f)
@staticmethod
def get_function(ea):
f = idaapi.get_func(ea)
setattr(f, "ctx", {})
return add_ea_int_cast(f)
def extract_function_features(self, f):
for (feature, ea) in capa.features.extractors.ida.function.extract_features(f):
yield feature, ea
def get_basic_blocks(self, f):
for bb in capa.features.extractors.ida.helpers.get_function_blocks(f):
yield add_ea_int_cast(bb)
def extract_basic_block_features(self, f, bb):
for (feature, ea) in capa.features.extractors.ida.basicblock.extract_features(f, bb):
yield feature, ea
def get_instructions(self, f, bb):
import capa.features.extractors.ida.helpers as ida_helpers
for insn in ida_helpers.get_instructions_in_range(bb.start_ea, bb.end_ea):
yield add_ea_int_cast(insn)
def extract_insn_features(self, f, bb, insn):
for (feature, ea) in capa.features.extractors.ida.insn.extract_features(f, bb, insn):
yield feature, ea

View File

@@ -1,4 +1,4 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
@@ -6,23 +6,25 @@
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import sys
import string
import struct
from typing import Tuple, Iterator
import idaapi
import capa.features.extractors.ida.helpers
from capa.features.common import Feature, Characteristic
from capa.features.address import Address
from capa.features import Characteristic
from capa.features.basicblock import BasicBlock
from capa.features.extractors.ida import helpers
from capa.features.extractors.helpers import MIN_STACKSTRING_LEN
from capa.features.extractors.base_extractor import BBHandle, FunctionHandle
def get_printable_len(op: idaapi.op_t) -> int:
"""Return string length if all operand bytes are ascii or utf16-le printable"""
def get_printable_len(op):
"""Return string length if all operand bytes are ascii or utf16-le printable
args:
op (IDA op_t)
"""
op_val = capa.features.extractors.ida.helpers.mask_op_val(op)
if op.dtype == idaapi.dt_byte:
@@ -34,14 +36,21 @@ def get_printable_len(op: idaapi.op_t) -> int:
elif op.dtype == idaapi.dt_qword:
chars = struct.pack("<Q", op_val)
else:
raise ValueError(f"Unhandled operand data type 0x{op.dtype:x}.")
raise ValueError("Unhandled operand data type 0x%x." % op.dtype)
def is_printable_ascii(chars_: bytes):
return all(c < 127 and chr(c) in string.printable for c in chars_)
def is_printable_ascii(chars):
if sys.version_info[0] >= 3:
return all(c < 127 and chr(c) in string.printable for c in chars)
else:
return all(ord(c) < 127 and c in string.printable for c in chars)
def is_printable_utf16le(chars_: bytes):
if all(c == 0x00 for c in chars_[1::2]):
return is_printable_ascii(chars_[::2])
def is_printable_utf16le(chars):
if sys.version_info[0] >= 3:
if all(c == 0x00 for c in chars[1::2]):
return is_printable_ascii(chars[::2])
else:
if all(c == "\x00" for c in chars[1::2]):
return is_printable_ascii(chars[::2])
if is_printable_ascii(chars):
return idaapi.get_dtype_size(op.dtype)
@@ -52,8 +61,12 @@ def get_printable_len(op: idaapi.op_t) -> int:
return 0
def is_mov_imm_to_stack(insn: idaapi.insn_t) -> bool:
"""verify instruction moves immediate onto stack"""
def is_mov_imm_to_stack(insn):
"""verify instruction moves immediate onto stack
args:
insn (IDA insn_t)
"""
if insn.Op2.type != idaapi.o_imm:
return False
@@ -66,10 +79,14 @@ def is_mov_imm_to_stack(insn: idaapi.insn_t) -> bool:
return True
def bb_contains_stackstring(f: idaapi.func_t, bb: idaapi.BasicBlock) -> bool:
def bb_contains_stackstring(f, bb):
"""check basic block for stackstring indicators
true if basic block contains enough moves of constant bytes to the stack
args:
f (IDA func_t)
bb (IDA BasicBlock)
"""
count = 0
for insn in capa.features.extractors.ida.helpers.get_instructions_in_range(bb.start_ea, bb.end_ea):
@@ -80,27 +97,57 @@ def bb_contains_stackstring(f: idaapi.func_t, bb: idaapi.BasicBlock) -> bool:
return False
def extract_bb_stackstring(fh: FunctionHandle, bbh: BBHandle) -> Iterator[Tuple[Feature, Address]]:
"""extract stackstring indicators from basic block"""
if bb_contains_stackstring(fh.inner, bbh.inner):
yield Characteristic("stack string"), bbh.address
def extract_bb_stackstring(f, bb):
"""extract stackstring indicators from basic block
args:
f (IDA func_t)
bb (IDA BasicBlock)
"""
if bb_contains_stackstring(f, bb):
yield Characteristic("stack string"), bb.start_ea
def extract_bb_tight_loop(fh: FunctionHandle, bbh: BBHandle) -> Iterator[Tuple[Feature, Address]]:
"""extract tight loop indicators from a basic block"""
if capa.features.extractors.ida.helpers.is_basic_block_tight_loop(bbh.inner):
yield Characteristic("tight loop"), bbh.address
def extract_bb_tight_loop(f, bb):
"""extract tight loop indicators from a basic block
args:
f (IDA func_t)
bb (IDA BasicBlock)
"""
if capa.features.extractors.ida.helpers.is_basic_block_tight_loop(bb):
yield Characteristic("tight loop"), bb.start_ea
def extract_features(fh: FunctionHandle, bbh: BBHandle) -> Iterator[Tuple[Feature, Address]]:
"""extract basic block features"""
def extract_features(f, bb):
"""extract basic block features
args:
f (IDA func_t)
bb (IDA BasicBlock)
"""
for bb_handler in BASIC_BLOCK_HANDLERS:
for feature, addr in bb_handler(fh, bbh):
yield feature, addr
yield BasicBlock(), bbh.address
for (feature, ea) in bb_handler(f, bb):
yield feature, ea
yield BasicBlock(), bb.start_ea
BASIC_BLOCK_HANDLERS = (
extract_bb_tight_loop,
extract_bb_stackstring,
)
def main():
features = []
for f in helpers.get_functions(skip_thunks=True, skip_libs=True):
for bb in idaapi.FlowChart(f, flags=idaapi.FC_PREDS):
features.extend(list(extract_features(f, bb)))
import pprint
pprint.pprint(features)
if __name__ == "__main__":
main()

View File

@@ -1,82 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import List, Tuple, Iterator
import idaapi
import ida_nalt
import capa.ida.helpers
import capa.features.extractors.elf
import capa.features.extractors.ida.file
import capa.features.extractors.ida.insn
import capa.features.extractors.ida.global_
import capa.features.extractors.ida.function
import capa.features.extractors.ida.basicblock
from capa.features.common import Feature
from capa.features.address import Address, AbsoluteVirtualAddress
from capa.features.extractors.base_extractor import (
BBHandle,
InsnHandle,
SampleHashes,
FunctionHandle,
StaticFeatureExtractor,
)
class IdaFeatureExtractor(StaticFeatureExtractor):
def __init__(self):
super().__init__(
hashes=SampleHashes(
md5=ida_nalt.retrieve_input_file_md5(), sha1="(unknown)", sha256=ida_nalt.retrieve_input_file_sha256()
)
)
self.global_features: List[Tuple[Feature, Address]] = []
self.global_features.extend(capa.features.extractors.ida.file.extract_file_format())
self.global_features.extend(capa.features.extractors.ida.global_.extract_os())
self.global_features.extend(capa.features.extractors.ida.global_.extract_arch())
def get_base_address(self):
return AbsoluteVirtualAddress(idaapi.get_imagebase())
def extract_global_features(self):
yield from self.global_features
def extract_file_features(self):
yield from capa.features.extractors.ida.file.extract_features()
def get_functions(self) -> Iterator[FunctionHandle]:
import capa.features.extractors.ida.helpers as ida_helpers
# ignore library functions and thunk functions as identified by IDA
yield from ida_helpers.get_functions(skip_thunks=True, skip_libs=True)
@staticmethod
def get_function(ea: int) -> FunctionHandle:
f = idaapi.get_func(ea)
return FunctionHandle(address=AbsoluteVirtualAddress(f.start_ea), inner=f)
def extract_function_features(self, fh: FunctionHandle) -> Iterator[Tuple[Feature, Address]]:
yield from capa.features.extractors.ida.function.extract_features(fh)
def get_basic_blocks(self, fh: FunctionHandle) -> Iterator[BBHandle]:
import capa.features.extractors.ida.helpers as ida_helpers
for bb in ida_helpers.get_function_blocks(fh.inner):
yield BBHandle(address=AbsoluteVirtualAddress(bb.start_ea), inner=bb)
def extract_basic_block_features(self, fh: FunctionHandle, bbh: BBHandle) -> Iterator[Tuple[Feature, Address]]:
yield from capa.features.extractors.ida.basicblock.extract_features(fh, bbh)
def get_instructions(self, fh: FunctionHandle, bbh: BBHandle) -> Iterator[InsnHandle]:
import capa.features.extractors.ida.helpers as ida_helpers
for insn in ida_helpers.get_instructions_in_range(bbh.inner.start_ea, bbh.inner.end_ea):
yield InsnHandle(address=AbsoluteVirtualAddress(insn.ea), inner=insn)
def extract_insn_features(self, fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle):
yield from capa.features.extractors.ida.insn.extract_features(fh, bbh, ih)

View File

@@ -1,4 +1,4 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
@@ -7,29 +7,26 @@
# See the License for the specific language governing permissions and limitations under the License.
import struct
from typing import Tuple, Iterator
import idc
import idaapi
import idautils
import ida_entry
import capa.features.extractors.common
import capa.features.extractors.helpers
import capa.features.extractors.strings
import capa.features.extractors.ida.helpers
from capa.features.file import Export, Import, Section, FunctionName
from capa.features.common import FORMAT_PE, FORMAT_ELF, Format, String, Feature, Characteristic
from capa.features.address import NO_ADDRESS, Address, FileOffsetAddress, AbsoluteVirtualAddress
MAX_OFFSET_PE_AFTER_MZ = 0x200
from capa.features import String, Characteristic
from capa.features.file import Export, Import, Section
def check_segment_for_pe(seg: idaapi.segment_t) -> Iterator[Tuple[int, int]]:
def check_segment_for_pe(seg):
"""check segment for embedded PE
adapted for IDA from:
https://github.com/vivisect/vivisect/blob/91e8419a861f49779f18316f155311967e696836/PE/carve.py#L25
https://github.com/vivisect/vivisect/blob/7be4037b1cecc4551b397f840405a1fc606f9b53/PE/carve.py#L19
args:
seg (IDA segment_t)
"""
seg_max = seg.end_ea
mz_xor = [
@@ -42,15 +39,14 @@ def check_segment_for_pe(seg: idaapi.segment_t) -> Iterator[Tuple[int, int]]:
]
todo = []
for mzx, pex, i in mz_xor:
# find all segment offsets containing XOR'd "MZ" bytes
for (mzx, pex, i) in mz_xor:
for off in capa.features.extractors.ida.helpers.find_byte_sequence(seg.start_ea, seg.end_ea, mzx):
todo.append((off, mzx, pex, i))
while len(todo):
off, mzx, pex, i = todo.pop()
# MZ header has one field we will check e_lfanew is at 0x3c
# The MZ header has one field we will check e_lfanew is at 0x3c
e_lfanew = off + 0x3C
if seg_max < (e_lfanew + 4):
@@ -58,19 +54,18 @@ def check_segment_for_pe(seg: idaapi.segment_t) -> Iterator[Tuple[int, int]]:
newoff = struct.unpack("<I", capa.features.extractors.helpers.xor_static(idc.get_bytes(e_lfanew, 4), i))[0]
# assume XOR'd "PE" bytes exist within threshold
if newoff > MAX_OFFSET_PE_AFTER_MZ:
continue
peoff = off + newoff
if seg_max < (peoff + 2):
continue
if idc.get_bytes(peoff, 2) == pex:
yield off, i
yield (off, i)
for nextres in capa.features.extractors.ida.helpers.find_byte_sequence(off + 1, seg.end_ea, mzx):
todo.append((nextres, mzx, pex, i))
def extract_file_embedded_pe() -> Iterator[Tuple[Feature, Address]]:
def extract_file_embedded_pe():
"""extract embedded PE features
IDA must load resource sections for this to be complete
@@ -78,23 +73,17 @@ def extract_file_embedded_pe() -> Iterator[Tuple[Feature, Address]]:
- Check 'Load resource sections' when opening binary in IDA manually
"""
for seg in capa.features.extractors.ida.helpers.get_segments(skip_header_segments=True):
for ea, _ in check_segment_for_pe(seg):
yield Characteristic("embedded pe"), FileOffsetAddress(ea)
for (ea, _) in check_segment_for_pe(seg):
yield Characteristic("embedded pe"), ea
def extract_file_export_names() -> Iterator[Tuple[Feature, Address]]:
"""extract function exports"""
for _, ordinal, ea, name in idautils.Entries():
forwarded_name = ida_entry.get_entry_forwarder(ordinal)
if forwarded_name is None:
yield Export(name), AbsoluteVirtualAddress(ea)
else:
forwarded_name = capa.features.extractors.helpers.reformat_forwarded_export_name(forwarded_name)
yield Export(forwarded_name), AbsoluteVirtualAddress(ea)
yield Characteristic("forwarded export"), AbsoluteVirtualAddress(ea)
def extract_file_export_names():
""" extract function exports """
for (_, _, ea, name) in idautils.Entries():
yield Export(name), ea
def extract_file_import_names() -> Iterator[Tuple[Feature, Address]]:
def extract_file_import_names():
"""extract function imports
1. imports by ordinal:
@@ -105,32 +94,28 @@ def extract_file_import_names() -> Iterator[Tuple[Feature, Address]]:
- modulename.importname
- importname
"""
for ea, info in capa.features.extractors.ida.helpers.get_file_imports().items():
addr = AbsoluteVirtualAddress(ea)
for (ea, info) in capa.features.extractors.ida.helpers.get_file_imports().items():
if info[1] and info[2]:
# e.g. in mimikatz: ('cabinet', 'FCIAddFile', 11L)
# extract by name here and by ordinal below
for name in capa.features.extractors.helpers.generate_symbols(info[0], info[1], include_dll=True):
yield Import(name), addr
for name in capa.features.extractors.helpers.generate_symbols(info[0], info[1]):
yield Import(name), ea
dll = info[0]
symbol = f"#{info[2]}"
symbol = "#%d" % (info[2])
elif info[1]:
dll = info[0]
symbol = info[1]
elif info[2]:
dll = info[0]
symbol = f"#{info[2]}"
symbol = "#%d" % (info[2])
else:
continue
for name in capa.features.extractors.helpers.generate_symbols(dll, symbol, include_dll=True):
yield Import(name), addr
for ea, info in capa.features.extractors.ida.helpers.get_file_externs().items():
yield Import(info[1]), AbsoluteVirtualAddress(ea)
for name in capa.features.extractors.helpers.generate_symbols(dll, symbol):
yield Import(name), ea
def extract_file_section_names() -> Iterator[Tuple[Feature, Address]]:
def extract_file_section_names():
"""extract section names
IDA must load resource sections for this to be complete
@@ -138,10 +123,10 @@ def extract_file_section_names() -> Iterator[Tuple[Feature, Address]]:
- Check 'Load resource sections' when opening binary in IDA manually
"""
for seg in capa.features.extractors.ida.helpers.get_segments(skip_header_segments=True):
yield Section(idaapi.get_segm_name(seg)), AbsoluteVirtualAddress(seg.start_ea)
yield Section(idaapi.get_segm_name(seg)), seg.start_ea
def extract_file_strings() -> Iterator[Tuple[Feature, Address]]:
def extract_file_strings():
"""extract ASCII and UTF-16 LE strings
IDA must load resource sections for this to be complete
@@ -151,50 +136,18 @@ def extract_file_strings() -> Iterator[Tuple[Feature, Address]]:
for seg in capa.features.extractors.ida.helpers.get_segments():
seg_buff = capa.features.extractors.ida.helpers.get_segment_buffer(seg)
# differing to common string extractor factor in segment offset here
for s in capa.features.extractors.strings.extract_ascii_strings(seg_buff):
yield String(s.s), FileOffsetAddress(seg.start_ea + s.offset)
yield String(s.s), (seg.start_ea + s.offset)
for s in capa.features.extractors.strings.extract_unicode_strings(seg_buff):
yield String(s.s), FileOffsetAddress(seg.start_ea + s.offset)
yield String(s.s), (seg.start_ea + s.offset)
def extract_file_function_names() -> Iterator[Tuple[Feature, Address]]:
"""
extract the names of statically-linked library functions.
"""
for ea in idautils.Functions():
addr = AbsoluteVirtualAddress(ea)
if idaapi.get_func(ea).flags & idaapi.FUNC_LIB:
name = idaapi.get_name(ea)
yield FunctionName(name), addr
if name.startswith("_"):
# some linkers may prefix linked routines with a `_` to avoid name collisions.
# extract features for both the mangled and un-mangled representations.
# e.g. `_fwrite` -> `fwrite`
# see: https://stackoverflow.com/a/2628384/87207
yield FunctionName(name[1:]), addr
def extract_file_format() -> Iterator[Tuple[Feature, Address]]:
file_info = idaapi.get_inf_structure()
if file_info.filetype in (idaapi.f_PE, idaapi.f_COFF):
yield Format(FORMAT_PE), NO_ADDRESS
elif file_info.filetype == idaapi.f_ELF:
yield Format(FORMAT_ELF), NO_ADDRESS
elif file_info.filetype == idaapi.f_BIN:
# no file type to return when processing a binary file, but we want to continue processing
return
else:
raise NotImplementedError(f"unexpected file format: {file_info.filetype}")
def extract_features() -> Iterator[Tuple[Feature, Address]]:
"""extract file features"""
def extract_features():
""" extract file features """
for file_handler in FILE_HANDLERS:
for feature, addr in file_handler():
yield feature, addr
for feature, va in file_handler():
yield feature, va
FILE_HANDLERS = (
@@ -203,6 +156,15 @@ FILE_HANDLERS = (
extract_file_strings,
extract_file_section_names,
extract_file_embedded_pe,
extract_file_function_names,
extract_file_format,
)
def main():
""" """
import pprint
pprint.pprint(list(extract_features()))
if __name__ == "__main__":
main()

View File

@@ -1,31 +1,35 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import Tuple, Iterator
import idaapi
import idautils
import capa.features.extractors.ida.helpers
from capa.features.common import Feature, Characteristic
from capa.features.address import Address, AbsoluteVirtualAddress
from capa.features import Characteristic
from capa.features.extractors import loops
from capa.features.extractors.base_extractor import FunctionHandle
def extract_function_calls_to(fh: FunctionHandle):
"""extract callers to a function"""
for ea in idautils.CodeRefsTo(fh.inner.start_ea, True):
yield Characteristic("calls to"), AbsoluteVirtualAddress(ea)
def extract_function_calls_to(f):
"""extract callers to a function
args:
f (IDA func_t)
"""
for ea in idautils.CodeRefsTo(f.start_ea, True):
yield Characteristic("calls to"), ea
def extract_function_loop(fh: FunctionHandle):
"""extract loop indicators from a function"""
f: idaapi.func_t = fh.inner
def extract_function_loop(f):
"""extract loop indicators from a function
args:
f (IDA func_t)
"""
edges = []
# construct control flow graph
@@ -34,19 +38,43 @@ def extract_function_loop(fh: FunctionHandle):
edges.append((bb.start_ea, succ.start_ea))
if loops.has_loop(edges):
yield Characteristic("loop"), fh.address
yield Characteristic("loop"), f.start_ea
def extract_recursive_call(fh: FunctionHandle):
"""extract recursive function call"""
if capa.features.extractors.ida.helpers.is_function_recursive(fh.inner):
yield Characteristic("recursive call"), fh.address
def extract_recursive_call(f):
"""extract recursive function call
args:
f (IDA func_t)
"""
if capa.features.extractors.ida.helpers.is_function_recursive(f):
yield Characteristic("recursive call"), f.start_ea
def extract_features(fh: FunctionHandle) -> Iterator[Tuple[Feature, Address]]:
def extract_features(f):
"""extract function features
arg:
f (IDA func_t)
"""
for func_handler in FUNCTION_HANDLERS:
for feature, addr in func_handler(fh):
yield feature, addr
for (feature, ea) in func_handler(f):
yield feature, ea
FUNCTION_HANDLERS = (extract_function_calls_to, extract_function_loop, extract_recursive_call)
def main():
""" """
features = []
for f in capa.features.extractors.ida.get_functions(skip_thunks=True, skip_libs=True):
features.extend(list(extract_features(f)))
import pprint
pprint.pprint(features)
if __name__ == "__main__":
main()

View File

@@ -1,65 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
import contextlib
from typing import Tuple, Iterator
import idaapi
import ida_loader
import capa.ida.helpers
import capa.features.extractors.elf
from capa.features.common import OS, ARCH_I386, ARCH_AMD64, OS_WINDOWS, Arch, Feature
from capa.features.address import NO_ADDRESS, Address
logger = logging.getLogger(__name__)
def extract_os() -> Iterator[Tuple[Feature, Address]]:
format_name: str = ida_loader.get_file_type_name()
if "PE" in format_name:
yield OS(OS_WINDOWS), NO_ADDRESS
elif "ELF" in format_name:
with contextlib.closing(capa.ida.helpers.IDAIO()) as f:
os = capa.features.extractors.elf.detect_elf_os(f)
yield OS(os), NO_ADDRESS
else:
# we likely end up here:
# 1. handling shellcode, or
# 2. handling a new file format (e.g. macho)
#
# for (1) we can't do much - its shellcode and all bets are off.
# we could maybe accept a further CLI argument to specify the OS,
# but i think this would be rarely used.
# rules that rely on OS conditions will fail to match on shellcode.
#
# for (2), this logic will need to be updated as the format is implemented.
logger.debug("unsupported file format: %s, will not guess OS", format_name)
return
def extract_arch() -> Iterator[Tuple[Feature, Address]]:
info: idaapi.idainfo = idaapi.get_inf_structure()
if info.procname == "metapc" and info.is_64bit():
yield Arch(ARCH_AMD64), NO_ADDRESS
elif info.procname == "metapc" and info.is_32bit():
yield Arch(ARCH_I386), NO_ADDRESS
elif info.procname == "metapc":
logger.debug("unsupported architecture: non-32-bit nor non-64-bit intel")
return
else:
# we likely end up here:
# 1. handling a new architecture (e.g. aarch64)
#
# for (1), this logic will need to be updated as the format is implemented.
logger.debug("unsupported architecture: %s", info.procname)
return

View File

@@ -1,24 +1,21 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import functools
from typing import Any, Dict, Tuple, Iterator, Optional
import sys
import string
import idc
import idaapi
import idautils
import ida_bytes
import ida_segment
from capa.features.address import AbsoluteVirtualAddress
from capa.features.extractors.base_extractor import FunctionHandle
def find_byte_sequence(start: int, end: int, seq: bytes) -> Iterator[int]:
def find_byte_sequence(start, end, seq):
"""yield all ea of a given byte sequence
args:
@@ -26,33 +23,36 @@ def find_byte_sequence(start: int, end: int, seq: bytes) -> Iterator[int]:
end: max virtual address
seq: bytes to search e.g. b"\x01\x03"
"""
seqstr = " ".join([f"{b:02x}" for b in seq])
if sys.version_info[0] >= 3:
seq = " ".join(["%02x" % b for b in seq])
else:
seq = " ".join(["%02x" % ord(b) for b in seq])
while True:
# TODO(mike-hunhoff): find_binary is deprecated. Please use ida_bytes.bin_search() instead.
# https://github.com/mandiant/capa/issues/1606
ea = idaapi.find_binary(start, end, seqstr, 0, idaapi.SEARCH_DOWN)
ea = idaapi.find_binary(start, end, seq, 0, idaapi.SEARCH_DOWN)
if ea == idaapi.BADADDR:
break
start = ea + 1
yield ea
def get_functions(
start: Optional[int] = None, end: Optional[int] = None, skip_thunks: bool = False, skip_libs: bool = False
) -> Iterator[FunctionHandle]:
def get_functions(start=None, end=None, skip_thunks=False, skip_libs=False):
"""get functions, range optional
args:
start: min virtual address
end: max virtual address
ret:
yield func_t*
"""
for ea in idautils.Functions(start=start, end=end):
f = idaapi.get_func(ea)
if not (skip_thunks and (f.flags & idaapi.FUNC_THUNK) or skip_libs and (f.flags & idaapi.FUNC_LIB)):
yield FunctionHandle(address=AbsoluteVirtualAddress(ea), inner=f)
yield f
def get_segments(skip_header_segments=False) -> Iterator[idaapi.segment_t]:
def get_segments(skip_header_segments=False):
"""get list of segments (sections) in the binary image
args:
@@ -64,7 +64,7 @@ def get_segments(skip_header_segments=False) -> Iterator[idaapi.segment_t]:
yield seg
def get_segment_buffer(seg: idaapi.segment_t) -> bytes:
def get_segment_buffer(seg):
"""return bytes stored in a given segment
decrease buffer size until IDA is able to read bytes from the segment
@@ -82,22 +82,9 @@ def get_segment_buffer(seg: idaapi.segment_t) -> bytes:
return buff if buff else b""
def inspect_import(imports, library, ea, function, ordinal):
if function and function.startswith("__imp_"):
# handle mangled PE imports
function = function[len("__imp_") :]
if function and "@@" in function:
# handle mangled ELF imports, like "fopen@@glibc_2.2.5"
function, _, _ = function.partition("@@")
imports[ea] = (library.lower(), function, ordinal)
return True
def get_file_imports() -> Dict[int, Tuple[str, str, int]]:
"""get file imports"""
imports: Dict[int, Tuple[str, str, int]] = {}
def get_file_imports():
""" get file imports """
imports = {}
for idx in range(idaapi.get_import_module_qty()):
library = idaapi.get_import_module_name(idx)
@@ -105,38 +92,26 @@ def get_file_imports() -> Dict[int, Tuple[str, str, int]]:
if not library:
continue
# IDA uses section names for the library of ELF imports, like ".dynsym".
# These are not useful to us, we may need to expand this list over time
# TODO(williballenthin): find all section names used by IDA
# https://github.com/mandiant/capa/issues/1419
if library == ".dynsym":
library = ""
def inspect_import(ea, function, ordinal):
if function and function.startswith("__imp_"):
# handle mangled names starting
function = function[len("__imp_") :]
imports[ea] = (library.lower(), function, ordinal)
return True
cb = functools.partial(inspect_import, imports, library)
idaapi.enum_import_names(idx, cb)
idaapi.enum_import_names(idx, inspect_import)
return imports
def get_file_externs() -> Dict[int, Tuple[str, str, int]]:
externs = {}
for seg in get_segments(skip_header_segments=True):
if seg.type != ida_segment.SEG_XTRN:
continue
for ea in idautils.Functions(seg.start_ea, seg.end_ea):
externs[ea] = ("", idaapi.get_func_name(ea), -1)
return externs
def get_instructions_in_range(start: int, end: int) -> Iterator[idaapi.insn_t]:
def get_instructions_in_range(start, end):
"""yield instructions in range
args:
start: virtual address (inclusive)
end: virtual address (exclusive)
yield:
(insn_t*)
"""
for head in idautils.Heads(start, end):
insn = idautils.DecodeInstruction(head)
@@ -144,8 +119,8 @@ def get_instructions_in_range(start: int, end: int) -> Iterator[idaapi.insn_t]:
yield insn
def is_operand_equal(op1: idaapi.op_t, op2: idaapi.op_t) -> bool:
"""compare two IDA op_t"""
def is_operand_equal(op1, op2):
""" compare two IDA op_t """
if op1.flags != op2.flags:
return False
@@ -170,8 +145,8 @@ def is_operand_equal(op1: idaapi.op_t, op2: idaapi.op_t) -> bool:
return True
def is_basic_block_equal(bb1: idaapi.BasicBlock, bb2: idaapi.BasicBlock) -> bool:
"""compare two IDA BasicBlock"""
def is_basic_block_equal(bb1, bb2):
""" compare two IDA BasicBlock """
if bb1.start_ea != bb2.start_ea:
return False
@@ -184,12 +159,12 @@ def is_basic_block_equal(bb1: idaapi.BasicBlock, bb2: idaapi.BasicBlock) -> bool
return True
def basic_block_size(bb: idaapi.BasicBlock) -> int:
"""calculate size of basic block"""
def basic_block_size(bb):
""" calculate size of basic block """
return bb.end_ea - bb.start_ea
def read_bytes_at(ea: int, count: int) -> bytes:
def read_bytes_at(ea, count):
""" """
# check if byte has a value, see get_wide_byte doc
if not idc.is_loaded(ea):
@@ -202,10 +177,10 @@ def read_bytes_at(ea: int, count: int) -> bytes:
return idc.get_bytes(ea, count)
def find_string_at(ea: int, min_: int = 4) -> str:
"""check if ASCII string exists at a given virtual address"""
def find_string_at(ea, min=4):
""" check if ASCII string exists at a given virtual address """
found = idaapi.get_strlit_contents(ea, -1, idaapi.STRTYPE_C)
if found and len(found) >= min_:
if found and len(found) > min:
try:
found = found.decode("ascii")
# hacky check for IDA bug; get_strlit_contents also reads Unicode as
@@ -219,7 +194,7 @@ def find_string_at(ea: int, min_: int = 4) -> str:
return ""
def get_op_phrase_info(op: idaapi.op_t) -> Dict:
def get_op_phrase_info(op):
"""parse phrase features from operand
Pretty much dup of sark's implementation:
@@ -229,8 +204,7 @@ def get_op_phrase_info(op: idaapi.op_t) -> Dict:
return {}
scale = 1 << ((op.specflag2 & 0xC0) >> 6)
# IDA ea_t may be 32- or 64-bit; we assume displacement can only be 32-bit
offset = op.addr & 0xFFFFFFFF
offset = op.addr
if op.specflag1 == 0:
index = None
@@ -257,45 +231,47 @@ def get_op_phrase_info(op: idaapi.op_t) -> Dict:
return {"base": base, "index": index, "scale": scale, "offset": offset}
def is_op_write(insn: idaapi.insn_t, op: idaapi.op_t) -> bool:
"""Check if an operand is written to (destination operand)"""
def is_op_write(insn, op):
""" Check if an operand is written to (destination operand) """
return idaapi.has_cf_chg(insn.get_canon_feature(), op.n)
def is_op_read(insn: idaapi.insn_t, op: idaapi.op_t) -> bool:
"""Check if an operand is read from (source operand)"""
def is_op_read(insn, op):
""" Check if an operand is read from (source operand) """
return idaapi.has_cf_use(insn.get_canon_feature(), op.n)
def is_op_offset(insn: idaapi.insn_t, op: idaapi.op_t) -> bool:
"""Check is an operand has been marked as an offset (by auto-analysis or manually)"""
def is_op_offset(insn, op):
""" Check is an operand has been marked as an offset (by auto-analysis or manually) """
flags = idaapi.get_flags(insn.ea)
return ida_bytes.is_off(flags, op.n)
def is_sp_modified(insn: idaapi.insn_t) -> bool:
"""determine if instruction modifies SP, ESP, RSP"""
return any(
op.reg == idautils.procregs.sp.reg and is_op_write(insn, op)
for op in get_insn_ops(insn, target_ops=(idaapi.o_reg,))
)
def is_sp_modified(insn):
""" determine if instruction modifies SP, ESP, RSP """
for op in get_insn_ops(insn, target_ops=(idaapi.o_reg,)):
if op.reg == idautils.procregs.sp.reg and is_op_write(insn, op):
# register is stack and written
return True
return False
def is_bp_modified(insn: idaapi.insn_t) -> bool:
"""check if instruction modifies BP, EBP, RBP"""
return any(
op.reg == idautils.procregs.bp.reg and is_op_write(insn, op)
for op in get_insn_ops(insn, target_ops=(idaapi.o_reg,))
)
def is_bp_modified(insn):
""" check if instruction modifies BP, EBP, RBP """
for op in get_insn_ops(insn, target_ops=(idaapi.o_reg,)):
if op.reg == idautils.procregs.bp.reg and is_op_write(insn, op):
# register is base and written
return True
return False
def is_frame_register(reg: int) -> bool:
"""check if register is sp or bp"""
def is_frame_register(reg):
""" check if register is sp or bp """
return reg in (idautils.procregs.sp.reg, idautils.procregs.bp.reg)
def get_insn_ops(insn: idaapi.insn_t, target_ops: Optional[Tuple[Any]] = None) -> idaapi.op_t:
"""yield op_t for instruction, filter on type if specified"""
def get_insn_ops(insn, target_ops=()):
""" yield op_t for instruction, filter on type if specified """
for op in insn.ops:
if op.type == idaapi.o_void:
# avoid looping all 6 ops if only subset exists
@@ -305,12 +281,12 @@ def get_insn_ops(insn: idaapi.insn_t, target_ops: Optional[Tuple[Any]] = None) -
yield op
def is_op_stack_var(ea: int, index: int) -> bool:
"""check if operand is a stack variable"""
def is_op_stack_var(ea, index):
""" check if operand is a stack variable """
return idaapi.is_stkvar(idaapi.get_flags(ea), index)
def mask_op_val(op: idaapi.op_t) -> int:
def mask_op_val(op):
"""mask value by data type
necessary due to a bug in AMD64
@@ -330,15 +306,26 @@ def mask_op_val(op: idaapi.op_t) -> int:
return masks.get(op.dtype, op.value) & op.value
def is_function_recursive(f: idaapi.func_t) -> bool:
"""check if function is recursive"""
return any(f.contains(ref) for ref in idautils.CodeRefsTo(f.start_ea, True))
def is_function_recursive(f):
"""check if function is recursive
args:
f (IDA func_t)
"""
for ref in idautils.CodeRefsTo(f.start_ea, True):
if f.contains(ref):
return True
return False
def is_basic_block_tight_loop(bb: idaapi.BasicBlock) -> bool:
def is_basic_block_tight_loop(bb):
"""check basic block loops to self
true if last instruction in basic block branches to basic block start
args:
f (IDA func_t)
bb (IDA BasicBlock)
"""
bb_end = idc.prev_head(bb.end_ea)
if bb.start_ea < bb_end:
@@ -348,8 +335,8 @@ def is_basic_block_tight_loop(bb: idaapi.BasicBlock) -> bool:
return False
def find_data_reference_from_insn(insn: idaapi.insn_t, max_depth: int = 10) -> int:
"""search for data reference from instruction, return address of instruction if no reference exists"""
def find_data_reference_from_insn(insn, max_depth=10):
""" search for data reference from instruction, return address of instruction if no reference exists """
depth = 0
ea = insn.ea
@@ -364,10 +351,6 @@ def find_data_reference_from_insn(insn: idaapi.insn_t, max_depth: int = 10) -> i
# break if circular reference
break
if not idaapi.is_mapped(data_refs[0]):
# break if address is not mapped
break
depth += 1
if depth > max_depth:
# break if max depth
@@ -378,17 +361,19 @@ def find_data_reference_from_insn(insn: idaapi.insn_t, max_depth: int = 10) -> i
return ea
def get_function_blocks(f: idaapi.func_t) -> Iterator[idaapi.BasicBlock]:
"""yield basic blocks contained in specified function"""
def get_function_blocks(f):
"""yield basic blocks contained in specified function
args:
f (IDA func_t)
yield:
block (IDA BasicBlock)
"""
# leverage idaapi.FC_NOEXT flag to ignore useless external blocks referenced by the function
yield from idaapi.FlowChart(f, flags=(idaapi.FC_PREDS | idaapi.FC_NOEXT))
for block in idaapi.FlowChart(f, flags=(idaapi.FC_PREDS | idaapi.FC_NOEXT)):
yield block
def is_basic_block_return(bb: idaapi.BasicBlock) -> bool:
"""check if basic block is return block"""
def is_basic_block_return(bb):
""" check if basic block is return block """
return bb.type == idaapi.fcb_ret
def has_sib(oper: idaapi.op_t) -> bool:
# via: https://reverseengineering.stackexchange.com/a/14300
return oper.specflag1 == 1

View File

@@ -1,11 +1,10 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import Any, Dict, Tuple, Iterator
import idc
import idaapi
@@ -13,30 +12,51 @@ import idautils
import capa.features.extractors.helpers
import capa.features.extractors.ida.helpers
from capa.features.insn import API, MAX_STRUCTURE_SIZE, Number, Offset, Mnemonic, OperandNumber, OperandOffset
from capa.features.common import MAX_BYTES_FEATURE_SIZE, THUNK_CHAIN_DEPTH_DELTA, Bytes, String, Feature, Characteristic
from capa.features.address import Address, AbsoluteVirtualAddress
from capa.features.extractors.base_extractor import BBHandle, InsnHandle, FunctionHandle
from capa.features import (
ARCH_X32,
ARCH_X64,
MAX_BYTES_FEATURE_SIZE,
THUNK_CHAIN_DEPTH_DELTA,
Bytes,
String,
Characteristic,
)
from capa.features.insn import API, Number, Offset, Mnemonic
# security cookie checks may perform non-zeroing XORs, these are expected within a certain
# byte range within the first and returning basic blocks, this helps to reduce FP features
SECURITY_COOKIE_BYTES_DELTA = 0x40
def get_imports(ctx: Dict[str, Any]) -> Dict[int, Any]:
def get_arch(ctx):
"""
fetch the ARCH_* constant for the currently open workspace.
via Tamir Bahar/@tmr232
https://reverseengineering.stackexchange.com/a/11398/17194
"""
if "arch" not in ctx:
info = idaapi.get_inf_structure()
if info.is_64bit():
ctx["arch"] = ARCH_X64
elif info.is_32bit():
ctx["arch"] = ARCH_X32
else:
raise ValueError("unexpected architecture")
return ctx["arch"]
def get_imports(ctx):
if "imports_cache" not in ctx:
ctx["imports_cache"] = capa.features.extractors.ida.helpers.get_file_imports()
return ctx["imports_cache"]
def get_externs(ctx: Dict[str, Any]) -> Dict[int, Any]:
if "externs_cache" not in ctx:
ctx["externs_cache"] = capa.features.extractors.ida.helpers.get_file_externs()
return ctx["externs_cache"]
def check_for_api_call(ctx, insn):
""" check instruction for API call """
if not insn.get_canon_mnem() in ("call", "jmp"):
return
def check_for_api_call(insn: idaapi.insn_t, funcs: Dict[int, Any]) -> Iterator[Any]:
"""check instruction for API call"""
info = ()
ref = insn.ea
@@ -52,7 +72,7 @@ def check_for_api_call(insn: idaapi.insn_t, funcs: Dict[int, Any]) -> Iterator[A
except IndexError:
break
info = funcs.get(ref, ())
info = get_imports(ctx).get(ref, ())
if info:
break
@@ -61,64 +81,37 @@ def check_for_api_call(insn: idaapi.insn_t, funcs: Dict[int, Any]) -> Iterator[A
break
if info:
yield info
yield "%s.%s" % (info[0], info[1])
def extract_insn_api_features(fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction API features
def extract_insn_api_features(f, bb, insn):
"""parse instruction API features
args:
f (IDA func_t)
bb (IDA BasicBlock)
insn (IDA insn_t)
example:
call dword [0x00473038]
call dword [0x00473038]
"""
insn: idaapi.insn_t = ih.inner
if insn.get_canon_mnem() not in ("call", "jmp"):
return
# check calls to imported functions
for api in check_for_api_call(insn, get_imports(fh.ctx)):
# tuple (<module>, <function>, <ordinal>)
for name in capa.features.extractors.helpers.generate_symbols(api[0], api[1]):
yield API(name), ih.address
# check calls to extern functions
for api in check_for_api_call(insn, get_externs(fh.ctx)):
# tuple (<module>, <function>, <ordinal>)
yield API(api[1]), ih.address
# extract IDA/FLIRT recognized API functions
targets = tuple(idautils.CodeRefsFrom(insn.ea, False))
if not targets:
return
target = targets[0]
target_func = idaapi.get_func(target)
if not target_func or target_func.start_ea != target:
# not a function (start)
return
if target_func.flags & idaapi.FUNC_LIB:
name = idaapi.get_name(target_func.start_ea)
yield API(name), ih.address
if name.startswith("_"):
# some linkers may prefix linked routines with a `_` to avoid name collisions.
# extract features for both the mangled and un-mangled representations.
# e.g. `_fwrite` -> `fwrite`
# see: https://stackoverflow.com/a/2628384/87207
yield API(name[1:]), ih.address
for api in check_for_api_call(f.ctx, insn):
dll, _, symbol = api.rpartition(".")
for name in capa.features.extractors.helpers.generate_symbols(dll, symbol):
yield API(name), insn.ea
def extract_insn_number_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction number features
def extract_insn_number_features(f, bb, insn):
"""parse instruction number features
args:
f (IDA func_t)
bb (IDA BasicBlock)
insn (IDA insn_t)
example:
push 3136B0h ; dwControlCode
"""
insn: idaapi.insn_t = ih.inner
if idaapi.is_ret_insn(insn):
# skip things like:
# .text:0042250E retn 8
@@ -129,11 +122,7 @@ def extract_insn_number_features(
# .text:00401145 add esp, 0Ch
return
for i, op in enumerate(insn.ops):
if op.type == idaapi.o_void:
break
if op.type not in (idaapi.o_imm, idaapi.o_mem):
continue
for op in capa.features.extractors.ida.helpers.get_insn_ops(insn, target_ops=(idaapi.o_imm, idaapi.o_mem)):
# skip things like:
# .text:00401100 shr eax, offset loc_C
if capa.features.extractors.ida.helpers.is_op_offset(insn, op):
@@ -144,27 +133,21 @@ def extract_insn_number_features(
else:
const = op.addr
yield Number(const), ih.address
yield OperandNumber(i, const), ih.address
if insn.itype == idaapi.NN_add and 0 < const < MAX_STRUCTURE_SIZE and op.type == idaapi.o_imm:
# for pattern like:
#
# add eax, 0x10
#
# assume 0x10 is also an offset (imagine eax is a pointer).
yield Offset(const), ih.address
yield OperandOffset(i, const), ih.address
yield Number(const), insn.ea
yield Number(const, arch=get_arch(f.ctx)), insn.ea
def extract_insn_bytes_features(fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""
parse referenced byte sequences
def extract_insn_bytes_features(f, bb, insn):
"""parse referenced byte sequences
args:
f (IDA func_t)
bb (IDA BasicBlock)
insn (IDA insn_t)
example:
push offset iid_004118d4_IShellLinkA ; riid
"""
insn: idaapi.insn_t = ih.inner
if idaapi.is_call_insn(insn):
return
@@ -172,54 +155,43 @@ def extract_insn_bytes_features(fh: FunctionHandle, bbh: BBHandle, ih: InsnHandl
if ref != insn.ea:
extracted_bytes = capa.features.extractors.ida.helpers.read_bytes_at(ref, MAX_BYTES_FEATURE_SIZE)
if extracted_bytes and not capa.features.extractors.helpers.all_zeros(extracted_bytes):
if not capa.features.extractors.ida.helpers.find_string_at(ref):
# don't extract byte features for obvious strings
yield Bytes(extracted_bytes), ih.address
yield Bytes(extracted_bytes), insn.ea
def extract_insn_string_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction string features
def extract_insn_string_features(f, bb, insn):
"""parse instruction string features
args:
f (IDA func_t)
bb (IDA BasicBlock)
insn (IDA insn_t)
example:
push offset aAcr ; "ACR > "
"""
insn: idaapi.insn_t = ih.inner
ref = capa.features.extractors.ida.helpers.find_data_reference_from_insn(insn)
if ref != insn.ea:
found = capa.features.extractors.ida.helpers.find_string_at(ref)
if found:
yield String(found), ih.address
yield String(found), insn.ea
def extract_insn_offset_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction structure offset features
def extract_insn_offset_features(f, bb, insn):
"""parse instruction structure offset features
args:
f (IDA func_t)
bb (IDA BasicBlock)
insn (IDA insn_t)
example:
.text:0040112F cmp [esi+4], ebx
"""
insn: idaapi.insn_t = ih.inner
for i, op in enumerate(insn.ops):
if op.type == idaapi.o_void:
break
if op.type not in (idaapi.o_phrase, idaapi.o_displ):
continue
for op in capa.features.extractors.ida.helpers.get_insn_ops(insn, target_ops=(idaapi.o_phrase, idaapi.o_displ)):
if capa.features.extractors.ida.helpers.is_op_stack_var(insn.ea, op.n):
continue
p_info = capa.features.extractors.ida.helpers.get_op_phrase_info(op)
op_off = p_info.get("offset")
if op_off is None:
continue
op_off = p_info.get("offset", 0)
if idaapi.is_mapped(op_off):
# Ignore:
# mov esi, dword_1005B148[esi]
@@ -230,32 +202,12 @@ def extract_insn_offset_features(
# https://stackoverflow.com/questions/31853189/x86-64-assembly-why-displacement-not-64-bits
op_off = capa.features.extractors.helpers.twos_complement(op_off, 32)
yield Offset(op_off), ih.address
yield OperandOffset(i, op_off), ih.address
if (
insn.itype == idaapi.NN_lea
and i == 1
# o_displ is used for both:
# [eax+1]
# [eax+ebx+2]
and op.type == idaapi.o_displ
# but the SIB is only present for [eax+ebx+2]
# which we don't want
and not capa.features.extractors.ida.helpers.has_sib(op)
):
# for pattern like:
#
# lea eax, [ebx + 1]
#
# assume 1 is also an offset (imagine ebx is a zero register).
yield Number(op_off), ih.address
yield OperandNumber(i, op_off), ih.address
yield Offset(op_off), insn.ea
yield Offset(op_off, arch=get_arch(f.ctx)), insn.ea
def contains_stack_cookie_keywords(s: str) -> bool:
"""
check if string contains stack cookie keywords
def contains_stack_cookie_keywords(s):
"""check if string contains stack cookie keywords
Examples:
xor ecx, ebp ; StackCookie
@@ -269,7 +221,7 @@ def contains_stack_cookie_keywords(s: str) -> bool:
return any(keyword in s for keyword in ("stack", "security"))
def bb_stack_cookie_registers(bb: idaapi.BasicBlock) -> Iterator[int]:
def bb_stack_cookie_registers(bb):
"""scan basic block for stack cookie operations
yield registers ids that may have been used for stack cookie operations
@@ -303,8 +255,8 @@ def bb_stack_cookie_registers(bb: idaapi.BasicBlock) -> Iterator[int]:
yield op.reg
def is_nzxor_stack_cookie_delta(f: idaapi.func_t, bb: idaapi.BasicBlock, insn: idaapi.insn_t) -> bool:
"""check if nzxor exists within stack cookie delta"""
def is_nzxor_stack_cookie_delta(f, bb, insn):
""" check if nzxor exists within stack cookie delta """
# security cookie check should use SP or BP
if not capa.features.extractors.ida.helpers.is_frame_register(insn.Op2.reg):
return False
@@ -326,8 +278,8 @@ def is_nzxor_stack_cookie_delta(f: idaapi.func_t, bb: idaapi.BasicBlock, insn: i
return False
def is_nzxor_stack_cookie(f: idaapi.func_t, bb: idaapi.BasicBlock, insn: idaapi.insn_t) -> bool:
"""check if nzxor is related to stack cookie"""
def is_nzxor_stack_cookie(f, bb, insn):
""" check if nzxor is related to stack cookie """
if contains_stack_cookie_keywords(idaapi.get_cmt(insn.ea, False)):
# Example:
# xor ecx, ebp ; StackCookie
@@ -343,49 +295,37 @@ def is_nzxor_stack_cookie(f: idaapi.func_t, bb: idaapi.BasicBlock, insn: idaapi.
return False
def extract_insn_nzxor_characteristic_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""
parse instruction non-zeroing XOR instruction
ignore expected non-zeroing XORs, e.g. security cookies
"""
insn: idaapi.insn_t = ih.inner
def extract_insn_nzxor_characteristic_features(f, bb, insn):
"""parse instruction non-zeroing XOR instruction
ignore expected non-zeroing XORs, e.g. security cookies
args:
f (IDA func_t)
bb (IDA BasicBlock)
insn (IDA insn_t)
"""
if insn.itype not in (idaapi.NN_xor, idaapi.NN_xorpd, idaapi.NN_xorps, idaapi.NN_pxor):
return
if capa.features.extractors.ida.helpers.is_operand_equal(insn.Op1, insn.Op2):
return
if is_nzxor_stack_cookie(fh.inner, bbh.inner, insn):
if is_nzxor_stack_cookie(f, bb, insn):
return
yield Characteristic("nzxor"), ih.address
yield Characteristic("nzxor"), insn.ea
def extract_insn_mnemonic_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""parse instruction mnemonic features"""
yield Mnemonic(idc.print_insn_mnem(ih.inner.ea)), ih.address
def extract_insn_mnemonic_features(f, bb, insn):
"""parse instruction mnemonic features
def extract_insn_obfs_call_plus_5_characteristic_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
args:
f (IDA func_t)
bb (IDA BasicBlock)
insn (IDA insn_t)
"""
parse call $+5 instruction from the given instruction.
"""
insn: idaapi.insn_t = ih.inner
if not idaapi.is_call_insn(insn):
return
if insn.ea + 5 == idc.get_operand_value(insn.ea, 0):
yield Characteristic("call $+5"), ih.address
yield Mnemonic(insn.get_canon_mnem()), insn.ea
def extract_insn_peb_access_characteristic_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
def extract_insn_peb_access_characteristic_features(f, bb, insn):
"""parse instruction peb access
fs:[0x30] on x86, gs:[0x60] on x64
@@ -393,61 +333,51 @@ def extract_insn_peb_access_characteristic_features(
TODO:
IDA should be able to do this..
"""
insn: idaapi.insn_t = ih.inner
if insn.itype not in (idaapi.NN_push, idaapi.NN_mov):
return
if all(op.type != idaapi.o_mem for op in insn.ops):
if all(map(lambda op: op.type != idaapi.o_mem, insn.ops)):
# try to optimize for only memory references
return
disasm = idc.GetDisasm(insn.ea)
if " fs:30h" in disasm or " gs:60h" in disasm:
# TODO(mike-hunhoff): use proper IDA API for fetching segment access
# scanning the disassembly text is a hack.
# https://github.com/mandiant/capa/issues/1605
yield Characteristic("peb access"), ih.address
# TODO: replace above with proper IDA
yield Characteristic("peb access"), insn.ea
def extract_insn_segment_access_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
def extract_insn_segment_access_features(f, bb, insn):
"""parse instruction fs or gs access
TODO:
IDA should be able to do this...
"""
insn: idaapi.insn_t = ih.inner
if all(op.type != idaapi.o_mem for op in insn.ops):
if all(map(lambda op: op.type != idaapi.o_mem, insn.ops)):
# try to optimize for only memory references
return
disasm = idc.GetDisasm(insn.ea)
if " fs:" in disasm:
# TODO(mike-hunhoff): use proper IDA API for fetching segment access
# scanning the disassembly text is a hack.
# https://github.com/mandiant/capa/issues/1605
yield Characteristic("fs access"), ih.address
# TODO: replace above with proper IDA
yield Characteristic("fs access"), insn.ea
if " gs:" in disasm:
# TODO(mike-hunhoff): use proper IDA API for fetching segment access
# scanning the disassembly text is a hack.
# https://github.com/mandiant/capa/issues/1605
yield Characteristic("gs access"), ih.address
# TODO: replace above with proper IDA
yield Characteristic("gs access"), insn.ea
def extract_insn_cross_section_cflow(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
"""inspect the instruction for a CALL or JMP that crosses section boundaries"""
insn: idaapi.insn_t = ih.inner
def extract_insn_cross_section_cflow(f, bb, insn):
"""inspect the instruction for a CALL or JMP that crosses section boundaries
args:
f (IDA func_t)
bb (IDA BasicBlock)
insn (IDA insn_t)
"""
for ref in idautils.CodeRefsFrom(insn.ea, False):
if ref in get_imports(fh.ctx):
if ref in get_imports(f.ctx).keys():
# ignore API calls
continue
if not idaapi.getseg(ref):
@@ -455,40 +385,50 @@ def extract_insn_cross_section_cflow(
continue
if idaapi.getseg(ref) == idaapi.getseg(insn.ea):
continue
yield Characteristic("cross section flow"), ih.address
yield Characteristic("cross section flow"), insn.ea
def extract_function_calls_from(fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
def extract_function_calls_from(f, bb, insn):
"""extract functions calls from features
most relevant at the function scope, however, its most efficient to extract at the instruction scope
"""
insn: idaapi.insn_t = ih.inner
args:
f (IDA func_t)
bb (IDA BasicBlock)
insn (IDA insn_t)
"""
if idaapi.is_call_insn(insn):
for ref in idautils.CodeRefsFrom(insn.ea, False):
yield Characteristic("calls from"), AbsoluteVirtualAddress(ref)
yield Characteristic("calls from"), ref
def extract_function_indirect_call_characteristic_features(
fh: FunctionHandle, bbh: BBHandle, ih: InsnHandle
) -> Iterator[Tuple[Feature, Address]]:
def extract_function_indirect_call_characteristic_features(f, bb, insn):
"""extract indirect function calls (e.g., call eax or call dword ptr [edx+4])
does not include calls like => call ds:dword_ABD4974
most relevant at the function or basic block scope;
however, its most efficient to extract at the instruction scope
args:
f (IDA func_t)
bb (IDA BasicBlock)
insn (IDA insn_t)
"""
insn: idaapi.insn_t = ih.inner
if idaapi.is_call_insn(insn) and idc.get_operand_type(insn.ea, 0) in (idc.o_reg, idc.o_phrase, idc.o_displ):
yield Characteristic("indirect call"), ih.address
yield Characteristic("indirect call"), insn.ea
def extract_features(f: FunctionHandle, bbh: BBHandle, insn: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
"""extract instruction features"""
def extract_features(f, bb, insn):
"""extract instruction features
args:
f (IDA func_t)
bb (IDA BasicBlock)
insn (IDA insn_t)
"""
for inst_handler in INSTRUCTION_HANDLERS:
for feature, ea in inst_handler(f, bbh, insn):
for (feature, ea) in inst_handler(f, bb, insn):
yield feature, ea
@@ -500,10 +440,26 @@ INSTRUCTION_HANDLERS = (
extract_insn_offset_features,
extract_insn_nzxor_characteristic_features,
extract_insn_mnemonic_features,
extract_insn_obfs_call_plus_5_characteristic_features,
extract_insn_peb_access_characteristic_features,
extract_insn_cross_section_cflow,
extract_insn_segment_access_features,
extract_function_calls_from,
extract_function_indirect_call_characteristic_features,
)
def main():
""" """
features = []
for f in capa.features.extractors.ida.helpers.get_functions(skip_thunks=True, skip_libs=True):
for bb in idaapi.FlowChart(f, flags=idaapi.FC_PREDS):
for insn in capa.features.extractors.ida.helpers.get_instructions_in_range(bb.start_ea, bb.end_ea):
features.extend(list(extract_features(f, bb, insn)))
import pprint
pprint.pprint(features)
if __name__ == "__main__":
main()

View File

@@ -1,4 +1,4 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
@@ -6,7 +6,7 @@
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import networkx
from networkx import nx
from networkx.algorithms.components import strongly_connected_components
@@ -20,6 +20,6 @@ def has_loop(edges, threshold=2):
returns:
bool
"""
g = networkx.DiGraph()
g = nx.DiGraph()
g.add_edges_from(edges)
return any(len(comp) >= threshold for comp in strongly_connected_components(g))

View File

@@ -0,0 +1,107 @@
# Copyright (C) 2020 FireEye, Inc.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: https://github.com/fireeye/capa/blob/master/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import miasm.analysis.binary
import miasm.analysis.machine
from miasm.core.locationdb import LocationDB
import capa.features.extractors.miasm.file
import capa.features.extractors.miasm.insn
import capa.features.extractors.miasm.function
import capa.features.extractors.miasm.basicblock
from capa.features.extractors import FeatureExtractor
class MiasmFeatureExtractor(FeatureExtractor):
def __init__(self, buf):
super(MiasmFeatureExtractor, self).__init__()
self.buf = buf
self.loc_db = LocationDB()
self.container = miasm.analysis.binary.Container.from_string(buf, self.loc_db)
self.pe = self.container.executable
self.machine = miasm.analysis.machine.Machine(self.container.arch)
self.cfg = self._build_cfg()
def get_base_address(self):
return self.container.entry_point
def extract_file_features(self):
for feature, va in capa.features.extractors.miasm.file.extract_file_features(self):
yield feature, va
# TODO: Improve this function (it just considers all loc_keys target of calls a function), port to miasm
def get_functions(self):
"""
returns all loc_keys which are the argument of any call function
"""
functions = set()
for block in self.cfg.blocks:
for line in block.lines:
if line.is_subcall() and line.args[0].is_loc():
loc_key = line.args[0].loc_key
if loc_key not in functions:
functions.add(loc_key)
yield loc_key
def extract_function_features(self, loc_key):
for feature, va in capa.features.extractors.miasm.function.extract_features(self, loc_key):
yield feature, va
def block_offset(self, bb):
return bb.lines[0].offset
def function_offset(self, f):
return self.cfg.loc_key_to_block(f).lines[0].offset
def get_basic_blocks(self, loc_key):
"""
get the basic blocks of the function represented by lock_key
"""
block = self.cfg.loc_key_to_block(loc_key)
disassembler = self.machine.dis_engine(self.container.bin_stream, loc_db=self.loc_db, follow_call=False)
cfg = disassembler.dis_multiblock(self.block_offset(block))
return cfg.blocks
def extract_basic_block_features(self, _, bb):
for feature, va in capa.features.extractors.miasm.basicblock.extract_features(bb):
yield feature, va
def get_instructions(self, _, bb):
return bb.lines
def extract_insn_features(self, f, bb, insn):
for feature, va in capa.features.extractors.miasm.insn.extract_features(self, f, bb, insn):
yield feature, va
def _get_entry_points(self):
entry_points = {self.get_base_address()}
for _, va in miasm.jitter.loader.pe.get_export_name_addr_list(self.pe):
entry_points.add(va)
return entry_points
# This is more efficient that using the `blocks` argument in `dis_multiblock`
# See http://www.williballenthin.com/post/2020-01-12-miasm-part-2
# TODO: port this efficiency improvement to miasm
def _build_cfg(self):
loc_db = self.container.loc_db
disassembler = self.machine.dis_engine(self.container.bin_stream, follow_call=True, loc_db=loc_db)
job_done = set()
cfgs = {}
for va in self._get_entry_points():
cfgs[va] = disassembler.dis_multiblock(va, job_done=job_done)
complete_cfs = miasm.core.asmblock.AsmCFG(loc_db)
for cfg in cfgs.values():
complete_cfs.merge(cfg)
disassembler.apply_splitting(complete_cfs)
return complete_cfs

View File

@@ -0,0 +1,134 @@
# Copyright (C) 2020 FireEye, Inc.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: https://github.com/fireeye/capa/blob/master/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import sys
import string
import struct
from capa.features import Characteristic
from capa.features.basicblock import BasicBlock
from capa.features.extractors.helpers import MIN_STACKSTRING_LEN
# TODO: Avoid this duplication (this code is in __init__ as well)
def block_offset(bb):
return bb.lines[0].offset
def extract_bb_tight_loop(bb):
""" check basic block for tight loop indicators """
if any(c.loc_key == bb.loc_key for c in bb.bto):
yield Characteristic("tight loop"), block_offset(bb)
def is_mov_imm_to_stack(instr):
"""
Return if instruction moves immediate onto stack
"""
if not instr.name.startswith("MOV"):
return False
try:
dst, src = instr.args
except ValueError:
# not two operands
return False
if not src.is_int():
return False
if not dst.is_mem():
return False
# should detect things like `@8[ESP + 0x8]` and `EBP` and not fail in other cases
if any(register in str(dst) for register in ["EBP", "RBP", "ESP", "RSP"]):
return True
return False
def is_printable_ascii(chars):
if sys.version_info >= (3, 0):
return all(c < 127 and chr(c) in string.printable for c in chars)
else:
return all(ord(c) < 127 and c in string.printable for c in chars)
def is_printable_utf16le(chars):
if all(c == b"\x00" for c in chars[1::2]):
return is_printable_ascii(chars[::2])
def get_printable_len(insn):
"""
Return string length if all operand bytes are ascii or utf16-le printable
"""
dst, src = insn.args
if not src.is_int():
return ValueError("unexpected operand type")
if not dst.is_mem():
return ValueError("unexpected operand type")
if isinstance(src.arg, int):
val = src.arg
else:
val = src.arg.arg
size = (val.bit_length() + 7) // 8
if size == 0:
return 0
elif size == 1:
chars = struct.pack("<B", val)
elif size == 2:
chars = struct.pack("<H", val)
elif size == 4:
chars = struct.pack("<I", val)
elif size == 8:
chars = struct.pack("<Q", val)
if is_printable_ascii(chars):
return size
if is_printable_utf16le(chars):
return size / 2
return 0
def extract_stackstring(bb):
""" check basic block for stackstring indicators """
count = 0
for line in bb.lines:
if is_mov_imm_to_stack(line):
count += get_printable_len(line)
if count > MIN_STACKSTRING_LEN:
yield Characteristic("stack string"), block_offset(bb)
return
def extract_features(bb):
"""
extract features from the given basic block.
args:
bb (miasm.core.asmblock.AsmBlock): the basic block to process.
yields:
Feature, set[VA]: the features and their location found in this basic block.
"""
yield BasicBlock(), block_offset(bb)
for bb_handler in BASIC_BLOCK_HANDLERS:
for feature, va in bb_handler(bb):
yield feature, va
BASIC_BLOCK_HANDLERS = (
extract_bb_tight_loop,
extract_stackstring,
)

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# Copyright (C) 2020 FireEye, Inc.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: https://github.com/fireeye/capa/blob/master/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import re
import miasm.analysis.binary
import capa.features.extractors.strings
from capa.features import String, Characteristic
from capa.features.file import Export, Import, Section
def extract_file_embedded_pe(extractor):
"""
extract embedded PE features
"""
buf = extractor.buf
for match in re.finditer(b"MZ", buf):
offset = match.start()
subcontainer = miasm.analysis.binary.ContainerPE.from_string(buf[offset:], loc_db=extractor.loc_db)
if isinstance(subcontainer, miasm.analysis.binary.ContainerPE):
yield Characteristic("embedded pe"), offset
def extract_file_export_names(extractor):
"""
extract file exports and their addresses
"""
for symbol, va in miasm.jitter.loader.pe.get_export_name_addr_list(extractor.pe):
# Only use func names and not ordinals
if isinstance(symbol, str):
yield Export(symbol), va
def extract_file_import_names(extractor):
"""
extract imported function names and their addresses
1. imports by ordinal:
- modulename.#ordinal
2. imports by name, results in two features to support importname-only matching:
- modulename.importname
- importname
"""
for ((dll, symbol), va_set) in miasm.jitter.loader.pe.get_import_address_pe(extractor.pe).items():
dll_name = dll[:-4] # Remove .dll
for va in va_set:
if isinstance(symbol, int):
yield Import("%s.#%s" % (dll_name, symbol)), va
else:
yield Import("%s.%s" % (dll_name, symbol)), va
yield Import(symbol), va
def extract_file_section_names(extractor):
"""
extract file sections and their addresses
"""
for section in extractor.pe.SHList.shlist:
name = section.name.partition(b"\x00")[0].decode("ascii")
va = section.addr
yield Section(name), va
def extract_file_strings(extractor):
"""
extract ASCII and UTF-16 LE strings from file
"""
for s in capa.features.extractors.strings.extract_ascii_strings(extractor.buf):
yield String(s.s), s.offset
for s in capa.features.extractors.strings.extract_unicode_strings(extractor.buf):
yield String(s.s), s.offset
def extract_file_features(extractor):
"""
extract file features from given buffer and parsed binary
args:
buf (bytes): binary content
container (miasm.analysis.binary.ContainerPE): parsed binary returned by miasm
yields:
Tuple[Feature, VA]: a feature and its location.
"""
for file_handler in FILE_HANDLERS:
for feature, va in file_handler(extractor):
yield feature, va
FILE_HANDLERS = (
extract_file_embedded_pe,
extract_file_export_names,
extract_file_import_names,
extract_file_section_names,
extract_file_strings,
)

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# Copyright (C) 2020 FireEye, Inc.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: https://github.com/fireeye/capa/blob/master/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from capa.features import Characteristic
def extract_function_calls_to(extractor, loc_key):
for pred_key in extractor.cfg.predecessors(loc_key):
pred_block = extractor.cfg.loc_key_to_block(pred_key)
pred_insn = pred_block.get_subcall_instr()
if pred_insn and pred_insn.is_subcall():
dst = pred_insn.args[0]
if dst.is_loc() and dst.loc_key == loc_key:
yield Characteristic("calls to"), pred_insn.offset
def extract_function_loop(extractor, loc_key):
"""
returns if the function has a loop
"""
block = extractor.cfg.loc_key_to_block(loc_key)
disassembler = extractor.machine.dis_engine(
extractor.container.bin_stream, loc_db=extractor.loc_db, follow_call=False
)
offset = extractor.block_offset(block)
cfg = disassembler.dis_multiblock(offset)
if cfg.has_loop():
yield Characteristic("loop"), offset
def extract_features(extractor, loc_key):
"""
extract features from the given function.
args:
cfg (AsmCFG): the CFG of the function from which to extract features
loc_key (LocKey): LocKey which represents the beginning of the function
yields:
Feature, set[VA]: the features and their location found in this function.
"""
for func_handler in FUNCTION_HANDLERS:
for feature, va in func_handler(extractor, loc_key):
yield feature, va
FUNCTION_HANDLERS = (extract_function_calls_to, extract_function_loop)

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# Copyright (C) 2020 FireEye, Inc.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: https://github.com/fireeye/capa/blob/master/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import miasm.expression.expression
import capa.features.extractors.helpers
from capa.features.insn import Mnemonic
# TODO: remove duplication (similar code in file.py)
# TODO: this function should be cached
def get_imports(pe):
imports = {}
for ((dll, symbol), va_set) in miasm.jitter.loader.pe.get_import_address_pe(pe).items():
dll_name = dll[:-4]
for va in va_set:
if isinstance(symbol, int):
imports[va] = "%s.#%s" % (dll_name, symbol)
else:
imports[va] = "%s.%s" % (dll_name, symbol)
return imports
def extract_insn_api_features(extractor, _f, _bb, insn):
"""parse API features from the given instruction."""
if insn.is_subcall():
arg = insn.args[0]
if isinstance(arg, miasm.expression.expression.ExprMem) and isinstance(
arg.ptr, miasm.expression.expression.ExprInt
):
target = int(arg.ptr)
imports = get_imports(extractor.pe)
if target in imports:
dll, _, symbol = imports[target].rpartition(".")
for feature in capa.features.extractors.helpers.generate_symbols(dll, symbol):
yield feature, insn.offset
def extract_insn_number_features(extractor, f, bb, insn):
"""parse number features from the given instruction."""
raise NotImplementedError()
def extract_insn_string_features(extractor, f, bb, insn):
"""parse string features from the given instruction."""
raise NotImplementedError()
def extract_insn_offset_features(extractor, f, bb, insn):
"""parse structure offset features from the given instruction."""
raise NotImplementedError()
def extract_insn_nzxor_characteristic_features(extractor, f, bb, insn):
"""
parse non-zeroing XOR instruction from the given instruction.
ignore expected non-zeroing XORs, e.g. security cookies.
"""
raise NotImplementedError()
def extract_insn_mnemonic_features(extractor, f, bb, insn):
"""parse mnemonic features from the given instruction."""
yield Mnemonic(insn.name), insn.offset
def extract_insn_peb_access_characteristic_features(extractor, f, bb, insn):
"""
parse peb access from the given function. fs:[0x30] on x86, gs:[0x60] on x64
"""
raise NotImplementedError()
def extract_insn_segment_access_features(extractor, f, bb, insn):
""" parse the instruction for access to fs or gs """
raise NotImplementedError()
def extract_insn_cross_section_cflow(extractor, f, bb, insn):
"""
inspect the instruction for a CALL or JMP that crosses section boundaries.
"""
raise NotImplementedError()
# this is a feature that's most relevant at the function scope,
# however, its most efficient to extract at the instruction scope.
def extract_function_calls_from(f, bb, insn):
raise NotImplementedError()
def extract_features(extractor, f, bb, insn):
"""
extract features from the given insn.
args:
extractor (MiasmFeatureExtractor)
f (miasm.expression.expression.LocKey): the function from which to extract features
bb (miasm.core.asmblock.AsmBlock): the basic block to process.
insn (Instruction): the instruction to process.
yields:
Feature, set[VA]: the features and their location found in this insn.
"""
for insn_handler in INSTRUCTION_HANDLERS:
for feature, va in insn_handler(extractor, f, bb, insn):
yield feature, va
INSTRUCTION_HANDLERS = (
extract_insn_api_features,
# extract_insn_number_features,
# extract_insn_string_features,
# extract_insn_bytes_features,
# extract_insn_offset_features,
# extract_insn_nzxor_characteristic_features,
extract_insn_mnemonic_features,
# extract_insn_peb_access_characteristic_features,
# extract_insn_cross_section_cflow,
# extract_insn_segment_access_features,
# extract_function_calls_from,
# extract_function_indirect_call_characteristic_features,
)

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@@ -1,170 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
from typing import Dict, List, Tuple, Union
from dataclasses import dataclass
from typing_extensions import TypeAlias
from capa.features.common import Feature
from capa.features.address import NO_ADDRESS, Address, ThreadAddress, ProcessAddress, DynamicCallAddress
from capa.features.extractors.base_extractor import (
BBHandle,
CallHandle,
InsnHandle,
SampleHashes,
ThreadHandle,
ProcessHandle,
FunctionHandle,
StaticFeatureExtractor,
DynamicFeatureExtractor,
)
@dataclass
class InstructionFeatures:
features: List[Tuple[Address, Feature]]
@dataclass
class BasicBlockFeatures:
features: List[Tuple[Address, Feature]]
instructions: Dict[Address, InstructionFeatures]
@dataclass
class FunctionFeatures:
features: List[Tuple[Address, Feature]]
basic_blocks: Dict[Address, BasicBlockFeatures]
@dataclass
class NullStaticFeatureExtractor(StaticFeatureExtractor):
"""
An extractor that extracts some user-provided features.
This is useful for testing, as we can provide expected values and see if matching works.
"""
base_address: Address
sample_hashes: SampleHashes
global_features: List[Feature]
file_features: List[Tuple[Address, Feature]]
functions: Dict[Address, FunctionFeatures]
def get_base_address(self):
return self.base_address
def get_sample_hashes(self) -> SampleHashes:
return self.sample_hashes
def extract_global_features(self):
for feature in self.global_features:
yield feature, NO_ADDRESS
def extract_file_features(self):
for address, feature in self.file_features:
yield feature, address
def get_functions(self):
for address in sorted(self.functions.keys()):
yield FunctionHandle(address, None)
def extract_function_features(self, f):
for address, feature in self.functions[f.address].features:
yield feature, address
def get_basic_blocks(self, f):
for address in sorted(self.functions[f.address].basic_blocks.keys()):
yield BBHandle(address, None)
def extract_basic_block_features(self, f, bb):
for address, feature in self.functions[f.address].basic_blocks[bb.address].features:
yield feature, address
def get_instructions(self, f, bb):
for address in sorted(self.functions[f.address].basic_blocks[bb.address].instructions.keys()):
yield InsnHandle(address, None)
def extract_insn_features(self, f, bb, insn):
for address, feature in self.functions[f.address].basic_blocks[bb.address].instructions[insn.address].features:
yield feature, address
@dataclass
class CallFeatures:
name: str
features: List[Tuple[Address, Feature]]
@dataclass
class ThreadFeatures:
features: List[Tuple[Address, Feature]]
calls: Dict[Address, CallFeatures]
@dataclass
class ProcessFeatures:
features: List[Tuple[Address, Feature]]
threads: Dict[Address, ThreadFeatures]
name: str
@dataclass
class NullDynamicFeatureExtractor(DynamicFeatureExtractor):
base_address: Address
sample_hashes: SampleHashes
global_features: List[Feature]
file_features: List[Tuple[Address, Feature]]
processes: Dict[Address, ProcessFeatures]
def extract_global_features(self):
for feature in self.global_features:
yield feature, NO_ADDRESS
def get_sample_hashes(self) -> SampleHashes:
return self.sample_hashes
def extract_file_features(self):
for address, feature in self.file_features:
yield feature, address
def get_processes(self):
for address in sorted(self.processes.keys()):
assert isinstance(address, ProcessAddress)
yield ProcessHandle(address=address, inner={})
def extract_process_features(self, ph):
for addr, feature in self.processes[ph.address].features:
yield feature, addr
def get_process_name(self, ph) -> str:
return self.processes[ph.address].name
def get_threads(self, ph):
for address in sorted(self.processes[ph.address].threads.keys()):
assert isinstance(address, ThreadAddress)
yield ThreadHandle(address=address, inner={})
def extract_thread_features(self, ph, th):
for addr, feature in self.processes[ph.address].threads[th.address].features:
yield feature, addr
def get_calls(self, ph, th):
for address in sorted(self.processes[ph.address].threads[th.address].calls.keys()):
assert isinstance(address, DynamicCallAddress)
yield CallHandle(address=address, inner={})
def extract_call_features(self, ph, th, ch):
for address, feature in self.processes[ph.address].threads[th.address].calls[ch.address].features:
yield feature, address
def get_call_name(self, ph, th, ch) -> str:
return self.processes[ph.address].threads[th.address].calls[ch.address].name
NullFeatureExtractor: TypeAlias = Union[NullStaticFeatureExtractor, NullDynamicFeatureExtractor]

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@@ -1,229 +0,0 @@
# Copyright (C) 2023 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import logging
from pathlib import Path
import pefile
import capa.features.common
import capa.features.extractors
import capa.features.extractors.common
import capa.features.extractors.helpers
import capa.features.extractors.strings
from capa.features.file import Export, Import, Section
from capa.features.common import OS, ARCH_I386, FORMAT_PE, ARCH_AMD64, OS_WINDOWS, Arch, Format, Characteristic
from capa.features.address import NO_ADDRESS, FileOffsetAddress, AbsoluteVirtualAddress
from capa.features.extractors.base_extractor import SampleHashes, StaticFeatureExtractor
logger = logging.getLogger(__name__)
def extract_file_embedded_pe(buf, **kwargs):
for offset, _ in capa.features.extractors.helpers.carve_pe(buf, 1):
yield Characteristic("embedded pe"), FileOffsetAddress(offset)
def extract_file_export_names(pe, **kwargs):
base_address = pe.OPTIONAL_HEADER.ImageBase
if hasattr(pe, "DIRECTORY_ENTRY_EXPORT"):
for export in pe.DIRECTORY_ENTRY_EXPORT.symbols:
if not export.name:
continue
try:
name = export.name.partition(b"\x00")[0].decode("ascii")
except UnicodeDecodeError:
continue
if export.forwarder is None:
va = base_address + export.address
yield Export(name), AbsoluteVirtualAddress(va)
else:
try:
forwarded_name = export.forwarder.partition(b"\x00")[0].decode("ascii")
except UnicodeDecodeError:
continue
forwarded_name = capa.features.extractors.helpers.reformat_forwarded_export_name(forwarded_name)
va = base_address + export.address
yield Export(forwarded_name), AbsoluteVirtualAddress(va)
yield Characteristic("forwarded export"), AbsoluteVirtualAddress(va)
def extract_file_import_names(pe, **kwargs):
"""
extract imported function names
1. imports by ordinal:
- modulename.#ordinal
2. imports by name, results in two features to support importname-only matching:
- modulename.importname
- importname
"""
if hasattr(pe, "DIRECTORY_ENTRY_IMPORT"):
for dll in pe.DIRECTORY_ENTRY_IMPORT:
try:
modname = dll.dll.partition(b"\x00")[0].decode("ascii")
except UnicodeDecodeError:
continue
# strip extension
modname = modname.rpartition(".")[0].lower()
for imp in dll.imports:
if imp.import_by_ordinal:
impname = f"#{imp.ordinal}"
else:
try:
impname = imp.name.partition(b"\x00")[0].decode("ascii")
except UnicodeDecodeError:
continue
for name in capa.features.extractors.helpers.generate_symbols(modname, impname, include_dll=True):
yield Import(name), AbsoluteVirtualAddress(imp.address)
def extract_file_section_names(pe, **kwargs):
base_address = pe.OPTIONAL_HEADER.ImageBase
for section in pe.sections:
try:
name = section.Name.partition(b"\x00")[0].decode("ascii")
except UnicodeDecodeError:
continue
yield Section(name), AbsoluteVirtualAddress(base_address + section.VirtualAddress)
def extract_file_strings(buf, **kwargs):
yield from capa.features.extractors.common.extract_file_strings(buf)
def extract_file_function_names(**kwargs):
"""
extract the names of statically-linked library functions.
"""
if False:
# using a `yield` here to force this to be a generator, not function.
yield NotImplementedError("pefile doesn't have library matching")
return
def extract_file_os(**kwargs):
# assuming PE -> Windows
# though i suppose they're also used by UEFI
yield OS(OS_WINDOWS), NO_ADDRESS
def extract_file_format(**kwargs):
yield Format(FORMAT_PE), NO_ADDRESS
def extract_file_arch(pe, **kwargs):
if pe.FILE_HEADER.Machine == pefile.MACHINE_TYPE["IMAGE_FILE_MACHINE_I386"]:
yield Arch(ARCH_I386), NO_ADDRESS
elif pe.FILE_HEADER.Machine == pefile.MACHINE_TYPE["IMAGE_FILE_MACHINE_AMD64"]:
yield Arch(ARCH_AMD64), NO_ADDRESS
else:
logger.warning("unsupported architecture: %s", pefile.MACHINE_TYPE[pe.FILE_HEADER.Machine])
def extract_file_features(pe, buf):
"""
extract file features from given workspace
args:
pe (pefile.PE): the parsed PE
buf: the raw sample bytes
yields:
Tuple[Feature, VA]: a feature and its location.
"""
for file_handler in FILE_HANDLERS:
# file_handler: type: (pe, bytes) -> Iterable[Tuple[Feature, Address]]
for feature, va in file_handler(pe=pe, buf=buf): # type: ignore
yield feature, va
FILE_HANDLERS = (
extract_file_embedded_pe,
extract_file_export_names,
extract_file_import_names,
extract_file_section_names,
extract_file_strings,
extract_file_function_names,
extract_file_format,
)
def extract_global_features(pe, buf):
"""
extract global features from given workspace
args:
pe (pefile.PE): the parsed PE
buf: the raw sample bytes
yields:
Tuple[Feature, VA]: a feature and its location.
"""
for handler in GLOBAL_HANDLERS:
# file_handler: type: (pe, bytes) -> Iterable[Tuple[Feature, Address]]
for feature, va in handler(pe=pe, buf=buf): # type: ignore
yield feature, va
GLOBAL_HANDLERS = (
extract_file_os,
extract_file_arch,
)
class PefileFeatureExtractor(StaticFeatureExtractor):
def __init__(self, path: Path):
super().__init__(hashes=SampleHashes.from_bytes(path.read_bytes()))
self.path: Path = path
self.pe = pefile.PE(str(path))
def get_base_address(self):
return AbsoluteVirtualAddress(self.pe.OPTIONAL_HEADER.ImageBase)
def extract_global_features(self):
buf = Path(self.path).read_bytes()
yield from extract_global_features(self.pe, buf)
def extract_file_features(self):
buf = Path(self.path).read_bytes()
yield from extract_file_features(self.pe, buf)
def get_functions(self):
raise NotImplementedError("PefileFeatureExtract can only be used to extract file features")
def extract_function_features(self, f):
raise NotImplementedError("PefileFeatureExtract can only be used to extract file features")
def get_basic_blocks(self, f):
raise NotImplementedError("PefileFeatureExtract can only be used to extract file features")
def extract_basic_block_features(self, f, bb):
raise NotImplementedError("PefileFeatureExtract can only be used to extract file features")
def get_instructions(self, f, bb):
raise NotImplementedError("PefileFeatureExtract can only be used to extract file features")
def extract_insn_features(self, f, bb, insn):
raise NotImplementedError("PefileFeatureExtract can only be used to extract file features")
def is_library_function(self, va):
raise NotImplementedError("PefileFeatureExtract can only be used to extract file features")
def get_function_name(self, va):
raise NotImplementedError("PefileFeatureExtract can only be used to extract file features")

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import sys
import types
from smda.common.SmdaReport import SmdaReport
from smda.common.SmdaInstruction import SmdaInstruction
import capa.features.extractors.smda.file
import capa.features.extractors.smda.insn
import capa.features.extractors.smda.function
import capa.features.extractors.smda.basicblock
from capa.main import UnsupportedRuntimeError
from capa.features.extractors import FeatureExtractor
class SmdaFeatureExtractor(FeatureExtractor):
def __init__(self, smda_report: SmdaReport, path):
super(SmdaFeatureExtractor, self).__init__()
if sys.version_info < (3, 0):
raise UnsupportedRuntimeError("SMDA should only be used with Python 3.")
self.smda_report = smda_report
self.path = path
def get_base_address(self):
return self.smda_report.base_addr
def extract_file_features(self):
for feature, va in capa.features.extractors.smda.file.extract_features(self.smda_report, self.path):
yield feature, va
def get_functions(self):
for function in self.smda_report.getFunctions():
yield function
def extract_function_features(self, f):
for feature, va in capa.features.extractors.smda.function.extract_features(f):
yield feature, va
def get_basic_blocks(self, f):
for bb in f.getBlocks():
yield bb
def extract_basic_block_features(self, f, bb):
for feature, va in capa.features.extractors.smda.basicblock.extract_features(f, bb):
yield feature, va
def get_instructions(self, f, bb):
for smda_ins in bb.getInstructions():
yield smda_ins
def extract_insn_features(self, f, bb, insn):
for feature, va in capa.features.extractors.smda.insn.extract_features(f, bb, insn):
yield feature, va

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import sys
import string
import struct
from capa.features import Characteristic
from capa.features.basicblock import BasicBlock
from capa.features.extractors.helpers import MIN_STACKSTRING_LEN
def _bb_has_tight_loop(f, bb):
"""
parse tight loops, true if last instruction in basic block branches to bb start
"""
return bb.offset in f.blockrefs[bb.offset] if bb.offset in f.blockrefs else False
def extract_bb_tight_loop(f, bb):
""" check basic block for tight loop indicators """
if _bb_has_tight_loop(f, bb):
yield Characteristic("tight loop"), bb.offset
def _bb_has_stackstring(f, bb):
"""
extract potential stackstring creation, using the following heuristics:
- basic block contains enough moves of constant bytes to the stack
"""
count = 0
for instr in bb.getInstructions():
if is_mov_imm_to_stack(instr):
count += get_printable_len(instr.getDetailed())
if count > MIN_STACKSTRING_LEN:
return True
return False
def get_operands(smda_ins):
return [o.strip() for o in smda_ins.operands.split(",")]
def extract_stackstring(f, bb):
""" check basic block for stackstring indicators """
if _bb_has_stackstring(f, bb):
yield Characteristic("stack string"), bb.offset
def is_mov_imm_to_stack(smda_ins):
"""
Return if instruction moves immediate onto stack
"""
if not smda_ins.mnemonic.startswith("mov"):
return False
try:
dst, src = get_operands(smda_ins)
except ValueError:
# not two operands
return False
try:
int(src, 16)
except ValueError:
return False
if not any(regname in dst for regname in ["ebp", "rbp", "esp", "rsp"]):
return False
return True
def is_printable_ascii(chars):
return all(c < 127 and chr(c) in string.printable for c in chars)
def is_printable_utf16le(chars):
if all(c == 0x00 for c in chars[1::2]):
return is_printable_ascii(chars[::2])
def get_printable_len(instr):
"""
Return string length if all operand bytes are ascii or utf16-le printable
Works on a capstone instruction
"""
# should have exactly two operands for mov immediate
if len(instr.operands) != 2:
return 0
op_value = instr.operands[1].value.imm
if instr.imm_size == 1:
chars = struct.pack("<B", op_value & 0xFF)
elif instr.imm_size == 2:
chars = struct.pack("<H", op_value & 0xFFFF)
elif instr.imm_size == 4:
chars = struct.pack("<I", op_value & 0xFFFFFFFF)
elif instr.imm_size == 8:
chars = struct.pack("<Q", op_value & 0xFFFFFFFFFFFFFFFF)
else:
raise ValueError("Unhandled operand data type 0x%x." % instr.imm_size)
if is_printable_ascii(chars):
return instr.imm_size
if is_printable_utf16le(chars):
return instr.imm_size // 2
return 0
def extract_features(f, bb):
"""
extract features from the given basic block.
args:
f (smda.common.SmdaFunction): the function from which to extract features
bb (smda.common.SmdaBasicBlock): the basic block to process.
yields:
Feature, set[VA]: the features and their location found in this basic block.
"""
yield BasicBlock(), bb.offset
for bb_handler in BASIC_BLOCK_HANDLERS:
for feature, va in bb_handler(f, bb):
yield feature, va
BASIC_BLOCK_HANDLERS = (
extract_bb_tight_loop,
extract_stackstring,
)

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import struct
# if we have SMDA we definitely have lief
import lief
import capa.features.extractors.helpers
import capa.features.extractors.strings
from capa.features import String, Characteristic
from capa.features.file import Export, Import, Section
def carve(pbytes, offset=0):
"""
Return a list of (offset, size, xor) tuples of embedded PEs
Based on the version from vivisect:
https://github.com/vivisect/vivisect/blob/7be4037b1cecc4551b397f840405a1fc606f9b53/PE/carve.py#L19
And its IDA adaptation:
capa/features/extractors/ida/file.py
"""
mz_xor = [
(
capa.features.extractors.helpers.xor_static(b"MZ", i),
capa.features.extractors.helpers.xor_static(b"PE", i),
i,
)
for i in range(256)
]
pblen = len(pbytes)
todo = [(pbytes.find(mzx, offset), mzx, pex, i) for mzx, pex, i in mz_xor]
todo = [(off, mzx, pex, i) for (off, mzx, pex, i) in todo if off != -1]
while len(todo):
off, mzx, pex, i = todo.pop()
# The MZ header has one field we will check
# e_lfanew is at 0x3c
e_lfanew = off + 0x3C
if pblen < (e_lfanew + 4):
continue
newoff = struct.unpack("<I", capa.features.extractors.helpers.xor_static(pbytes[e_lfanew : e_lfanew + 4], i))[0]
nextres = pbytes.find(mzx, off + 1)
if nextres != -1:
todo.append((nextres, mzx, pex, i))
peoff = off + newoff
if pblen < (peoff + 2):
continue
if pbytes[peoff : peoff + 2] == pex:
yield (off, i)
def extract_file_embedded_pe(smda_report, file_path):
with open(file_path, "rb") as f:
fbytes = f.read()
for offset, i in carve(fbytes, 1):
yield Characteristic("embedded pe"), offset
def extract_file_export_names(smda_report, file_path):
lief_binary = lief.parse(file_path)
if lief_binary is not None:
for function in lief_binary.exported_functions:
yield Export(function.name), function.address
def extract_file_import_names(smda_report, file_path):
# extract import table info via LIEF
lief_binary = lief.parse(file_path)
if not isinstance(lief_binary, lief.PE.Binary):
return
for imported_library in lief_binary.imports:
library_name = imported_library.name.lower()
library_name = library_name[:-4] if library_name.endswith(".dll") else library_name
for func in imported_library.entries:
if func.name:
va = func.iat_address + smda_report.base_addr
for name in capa.features.extractors.helpers.generate_symbols(library_name, func.name):
yield Import(name), va
elif func.is_ordinal:
for name in capa.features.extractors.helpers.generate_symbols(library_name, "#%s" % func.ordinal):
yield Import(name), va
def extract_file_section_names(smda_report, file_path):
lief_binary = lief.parse(file_path)
if not isinstance(lief_binary, lief.PE.Binary):
return
if lief_binary and lief_binary.sections:
base_address = lief_binary.optional_header.imagebase
for section in lief_binary.sections:
yield Section(section.name), base_address + section.virtual_address
def extract_file_strings(smda_report, file_path):
"""
extract ASCII and UTF-16 LE strings from file
"""
with open(file_path, "rb") as f:
b = f.read()
for s in capa.features.extractors.strings.extract_ascii_strings(b):
yield String(s.s), s.offset
for s in capa.features.extractors.strings.extract_unicode_strings(b):
yield String(s.s), s.offset
def extract_features(smda_report, file_path):
"""
extract file features from given workspace
args:
smda_report (smda.common.SmdaReport): a SmdaReport
file_path: path to the input file
yields:
Tuple[Feature, VA]: a feature and its location.
"""
for file_handler in FILE_HANDLERS:
result = file_handler(smda_report, file_path)
for feature, va in file_handler(smda_report, file_path):
yield feature, va
FILE_HANDLERS = (
extract_file_embedded_pe,
extract_file_export_names,
extract_file_import_names,
extract_file_section_names,
extract_file_strings,
)

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@@ -0,0 +1,38 @@
from capa.features import Characteristic
from capa.features.extractors import loops
def extract_function_calls_to(f):
for inref in f.inrefs:
yield Characteristic("calls to"), inref
def extract_function_loop(f):
"""
parse if a function has a loop
"""
edges = []
for bb_from, bb_tos in f.blockrefs.items():
for bb_to in bb_tos:
edges.append((bb_from, bb_to))
if edges and loops.has_loop(edges):
yield Characteristic("loop"), f.offset
def extract_features(f):
"""
extract features from the given function.
args:
f (smda.common.SmdaFunction): the function from which to extract features
yields:
Feature, set[VA]: the features and their location found in this function.
"""
for func_handler in FUNCTION_HANDLERS:
for feature, va in func_handler(f):
yield feature, va
FUNCTION_HANDLERS = (extract_function_calls_to, extract_function_loop)

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import re
import string
import struct
from smda.common.SmdaReport import SmdaReport
import capa.features.extractors.helpers
from capa.features import (
ARCH_X32,
ARCH_X64,
MAX_BYTES_FEATURE_SIZE,
THUNK_CHAIN_DEPTH_DELTA,
Bytes,
String,
Characteristic,
)
from capa.features.insn import API, Number, Offset, Mnemonic
# security cookie checks may perform non-zeroing XORs, these are expected within a certain
# byte range within the first and returning basic blocks, this helps to reduce FP features
SECURITY_COOKIE_BYTES_DELTA = 0x40
PATTERN_HEXNUM = re.compile(r"[+\-] (?P<num>0x[a-fA-F0-9]+)")
PATTERN_SINGLENUM = re.compile(r"[+\-] (?P<num>[0-9])")
def get_arch(smda_report):
if smda_report.architecture == "intel":
if smda_report.bitness == 32:
return ARCH_X32
elif smda_report.bitness == 64:
return ARCH_X64
else:
raise NotImplementedError
def extract_insn_api_features(f, bb, insn):
"""parse API features from the given instruction."""
if insn.offset in f.apirefs:
api_entry = f.apirefs[insn.offset]
# reformat
dll_name, api_name = api_entry.split("!")
dll_name = dll_name.split(".")[0]
dll_name = dll_name.lower()
for name in capa.features.extractors.helpers.generate_symbols(dll_name, api_name):
yield API(name), insn.offset
elif insn.offset in f.outrefs:
current_function = f
current_instruction = insn
for index in range(THUNK_CHAIN_DEPTH_DELTA):
if current_function and len(current_function.outrefs[current_instruction.offset]) == 1:
target = current_function.outrefs[current_instruction.offset][0]
referenced_function = current_function.smda_report.getFunction(target)
if referenced_function:
# TODO SMDA: implement this function for both jmp and call, checking if function has 1 instruction which refs an API
if referenced_function.isApiThunk():
api_entry = (
referenced_function.apirefs[target] if target in referenced_function.apirefs else None
)
if api_entry:
# reformat
dll_name, api_name = api_entry.split("!")
dll_name = dll_name.split(".")[0]
dll_name = dll_name.lower()
for name in capa.features.extractors.helpers.generate_symbols(dll_name, api_name):
yield API(name), insn.offset
elif referenced_function.num_instructions == 1 and referenced_function.num_outrefs == 1:
current_function = referenced_function
current_instruction = [i for i in referenced_function.getInstructions()][0]
else:
return
def extract_insn_number_features(f, bb, insn):
"""parse number features from the given instruction."""
# example:
#
# push 3136B0h ; dwControlCode
operands = [o.strip() for o in insn.operands.split(",")]
if insn.mnemonic == "add" and operands[0] in ["esp", "rsp"]:
# skip things like:
#
# .text:00401140 call sub_407E2B
# .text:00401145 add esp, 0Ch
return
for operand in operands:
try:
yield Number(int(operand, 16)), insn.offset
yield Number(int(operand, 16), arch=get_arch(f.smda_report)), insn.offset
except:
continue
def read_bytes(smda_report, va, num_bytes=None):
"""
read up to MAX_BYTES_FEATURE_SIZE from the given address.
"""
rva = va - smda_report.base_addr
if smda_report.buffer is None:
return
buffer_end = len(smda_report.buffer)
max_bytes = num_bytes if num_bytes is not None else MAX_BYTES_FEATURE_SIZE
if rva + max_bytes > buffer_end:
return smda_report.buffer[rva:]
else:
return smda_report.buffer[rva : rva + max_bytes]
def derefs(smda_report, p):
"""
recursively follow the given pointer, yielding the valid memory addresses along the way.
useful when you may have a pointer to string, or pointer to pointer to string, etc.
this is a "do what i mean" type of helper function.
based on the implementation in viv/insn.py
"""
depth = 0
while True:
if not smda_report.isAddrWithinMemoryImage(p):
return
yield p
bytes_ = read_bytes(smda_report, p, num_bytes=4)
val = struct.unpack("I", bytes_)[0]
# sanity: pointer points to self
if val == p:
return
# sanity: avoid chains of pointers that are unreasonably deep
depth += 1
if depth > 10:
return
p = val
def extract_insn_bytes_features(f, bb, insn):
"""
parse byte sequence features from the given instruction.
example:
# push offset iid_004118d4_IShellLinkA ; riid
"""
for data_ref in insn.getDataRefs():
for v in derefs(f.smda_report, data_ref):
bytes_read = read_bytes(f.smda_report, v)
if bytes_read is None:
continue
if capa.features.extractors.helpers.all_zeros(bytes_read):
continue
yield Bytes(bytes_read), insn.offset
def detect_ascii_len(smda_report, offset):
if smda_report.buffer is None:
return 0
ascii_len = 0
rva = offset - smda_report.base_addr
char = smda_report.buffer[rva]
while char < 127 and chr(char) in string.printable:
ascii_len += 1
rva += 1
char = smda_report.buffer[rva]
if char == 0:
return ascii_len
return 0
def detect_unicode_len(smda_report, offset):
if smda_report.buffer is None:
return 0
unicode_len = 0
rva = offset - smda_report.base_addr
char = smda_report.buffer[rva]
second_char = smda_report.buffer[rva + 1]
while char < 127 and chr(char) in string.printable and second_char == 0:
unicode_len += 2
rva += 2
char = smda_report.buffer[rva]
second_char = smda_report.buffer[rva + 1]
if char == 0 and second_char == 0:
return unicode_len
return 0
def read_string(smda_report, offset):
alen = detect_ascii_len(smda_report, offset)
if alen > 1:
return read_bytes(smda_report, offset, alen).decode("utf-8")
ulen = detect_unicode_len(smda_report, offset)
if ulen > 2:
return read_bytes(smda_report, offset, ulen).decode("utf-16")
def extract_insn_string_features(f, bb, insn):
"""parse string features from the given instruction."""
# example:
#
# push offset aAcr ; "ACR > "
for data_ref in insn.getDataRefs():
for v in derefs(f.smda_report, data_ref):
string_read = read_string(f.smda_report, v)
if string_read:
yield String(string_read.rstrip("\x00")), insn.offset
def extract_insn_offset_features(f, bb, insn):
"""parse structure offset features from the given instruction."""
# examples:
#
# mov eax, [esi + 4]
# mov eax, [esi + ecx + 16384]
operands = [o.strip() for o in insn.operands.split(",")]
for operand in operands:
if not "ptr" in operand:
continue
if "esp" in operand or "ebp" in operand or "rbp" in operand:
continue
number = 0
number_hex = re.search(PATTERN_HEXNUM, operand)
number_int = re.search(PATTERN_SINGLENUM, operand)
if number_hex:
number = int(number_hex.group("num"), 16)
number = -1 * number if number_hex.group().startswith("-") else number
elif number_int:
number = int(number_int.group("num"))
number = -1 * number if number_int.group().startswith("-") else number
yield Offset(number), insn.offset
yield Offset(number, arch=get_arch(f.smda_report)), insn.offset
def is_security_cookie(f, bb, insn):
"""
check if an instruction is related to security cookie checks
"""
# security cookie check should use SP or BP
operands = [o.strip() for o in insn.operands.split(",")]
if operands[1] not in ["esp", "ebp", "rsp", "rbp"]:
return False
for index, block in enumerate(f.getBlocks()):
# expect security cookie init in first basic block within first bytes (instructions)
block_instructions = [i for i in block.getInstructions()]
if index == 0 and insn.offset < (block_instructions[0].offset + SECURITY_COOKIE_BYTES_DELTA):
return True
# ... or within last bytes (instructions) before a return
if block_instructions[-1].mnemonic.startswith("ret") and insn.offset > (
block_instructions[-1].offset - SECURITY_COOKIE_BYTES_DELTA
):
return True
return False
def extract_insn_nzxor_characteristic_features(f, bb, insn):
"""
parse non-zeroing XOR instruction from the given instruction.
ignore expected non-zeroing XORs, e.g. security cookies.
"""
if insn.mnemonic not in ("xor", "xorpd", "xorps", "pxor"):
return
operands = [o.strip() for o in insn.operands.split(",")]
if operands[0] == operands[1]:
return
if is_security_cookie(f, bb, insn):
return
yield Characteristic("nzxor"), insn.offset
def extract_insn_mnemonic_features(f, bb, insn):
"""parse mnemonic features from the given instruction."""
yield Mnemonic(insn.mnemonic), insn.offset
def extract_insn_peb_access_characteristic_features(f, bb, insn):
"""
parse peb access from the given function. fs:[0x30] on x86, gs:[0x60] on x64
"""
if insn.mnemonic not in ["push", "mov"]:
return
operands = [o.strip() for o in insn.operands.split(",")]
for operand in operands:
if "fs:" in operand and "0x30" in operand:
yield Characteristic("peb access"), insn.offset
elif "gs:" in operand and "0x60" in operand:
yield Characteristic("peb access"), insn.offset
def extract_insn_segment_access_features(f, bb, insn):
""" parse the instruction for access to fs or gs """
operands = [o.strip() for o in insn.operands.split(",")]
for operand in operands:
if "fs:" in operand:
yield Characteristic("fs access"), insn.offset
elif "gs:" in operand:
yield Characteristic("gs access"), insn.offset
def extract_insn_cross_section_cflow(f, bb, insn):
"""
inspect the instruction for a CALL or JMP that crosses section boundaries.
"""
if insn.mnemonic in ["call", "jmp"]:
if insn.offset in f.apirefs:
return
smda_report = insn.smda_function.smda_report
if insn.offset in f.outrefs:
for target in f.outrefs[insn.offset]:
if smda_report.getSection(insn.offset) != smda_report.getSection(target):
yield Characteristic("cross section flow"), insn.offset
elif insn.operands.startswith("0x"):
target = int(insn.operands, 16)
if smda_report.getSection(insn.offset) != smda_report.getSection(target):
yield Characteristic("cross section flow"), insn.offset
# this is a feature that's most relevant at the function scope,
# however, its most efficient to extract at the instruction scope.
def extract_function_calls_from(f, bb, insn):
if insn.mnemonic != "call":
return
if insn.offset in f.outrefs:
for outref in f.outrefs[insn.offset]:
yield Characteristic("calls from"), outref
if outref == f.offset:
# if we found a jump target and it's the function address
# mark as recursive
yield Characteristic("recursive call"), outref
if insn.offset in f.apirefs:
yield Characteristic("calls from"), f.apirefs[insn.offset]
# this is a feature that's most relevant at the function or basic block scope,
# however, its most efficient to extract at the instruction scope.
def extract_function_indirect_call_characteristic_features(f, bb, insn):
"""
extract indirect function call characteristic (e.g., call eax or call dword ptr [edx+4])
does not include calls like => call ds:dword_ABD4974
"""
if insn.mnemonic != "call":
return
if insn.operands.startswith("0x"):
return False
if "qword ptr" in insn.operands and "rip" in insn.operands:
return False
if insn.operands.startswith("dword ptr [0x"):
return False
# call edx
# call dword ptr [eax+50h]
# call qword ptr [rsp+78h]
yield Characteristic("indirect call"), insn.offset
def extract_features(f, bb, insn):
"""
extract features from the given insn.
args:
f (smda.common.SmdaFunction): the function to process.
bb (smda.common.SmdaBasicBlock): the basic block to process.
insn (smda.common.SmdaInstruction): the instruction to process.
yields:
Feature, set[VA]: the features and their location found in this insn.
"""
for insn_handler in INSTRUCTION_HANDLERS:
for feature, va in insn_handler(f, bb, insn):
yield feature, va
INSTRUCTION_HANDLERS = (
extract_insn_api_features,
extract_insn_number_features,
extract_insn_string_features,
extract_insn_bytes_features,
extract_insn_offset_features,
extract_insn_nzxor_characteristic_features,
extract_insn_mnemonic_features,
extract_insn_peb_access_characteristic_features,
extract_insn_cross_section_cflow,
extract_insn_segment_access_features,
extract_function_calls_from,
extract_function_indirect_call_characteristic_features,
)

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