Merge branch 'master' into function-id-flirt

.gitattributes

@@ -0,0 +1,9 @@
+# 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

.github/ISSUE_TEMPLATE/bug_report.md

@@ -5,7 +5,7 @@ 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.
+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/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.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -5,7 +5,7 @@ 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.
+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/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.

.github/pull_request_template.md

@@ -0,0 +1,31 @@
+<!--
+Thank you for contributing to capa! <3
+
+IMPORTANT NOTE
+It's most important that you submit your improvements. So even if you don't use this complete template we look forward to collaborating!
+
+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/fireeye/capa/blob/master/.github/CONTRIBUTING.md
+
+PR template based on https://embeddedartistry.com/blog/2017/08/04/a-github-pull-request-template-for-your-projects/
+-->
+
+### Description
+
+<!-- Please describe the changes in this PR. Include your motivation and context to help us review. -->
+
+closes # (issue)
+
+### Documentation
+
+- [ ] I have updated the [CHANGELOG.md](/CHANGELOG.md), this is required for:
+  - Bug fixes (non-breaking change which fixes an issue)
+  - New features (non-breaking change which adds functionality)
+  - Breaking changes (fix or feature that would cause existing functionality to not work as expected)
+- [ ] This change requires a documentation update
+  - [ ] I have made the corresponding changes to the documentation
+
+### Tests
+
+- [ ] I have added tests that prove my fix is effective or that my feature works
+- [ ] No new tests needed

.github/workflows/build.yml

@@ -1,3 +1,4 @@
+<<<<<<< HEAD
 name: build
 
 on:
@@ -79,3 +80,117 @@ jobs:
           repo_token: ${{ secrets.GITHUB_TOKEN}}
           file: ${{ env.zip_name }}
           tag: ${{ github.ref }}
+=======
+name: build
+
+on:
+  push:
+    branches: [master]
+  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-2019
+            artifact_name: capa.exe
+            asset_name: windows
+          - os: macos-10.15
+            artifact_name: capa
+            asset_name: macos
+    steps:
+      - name: Checkout capa
+        uses: actions/checkout@v2
+        with:
+          submodules: true
+      # using Python 3.8 to support running across multiple operating systems including Windows 7
+      - name: Set up Python 3.8
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.8
+      - if: matrix.os == 'ubuntu-16.04'
+        run: sudo apt-get install -y libyaml-dev
+      - name: Install PyInstaller
+        run: pip install 'pyinstaller==4.2'
+      - 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 }}
+
+  test_run:
+    # test that binaries run on push to master
+    if: github.event_name == 'push'
+    name: Test run on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    needs: [build]
+    strategy:
+      matrix:
+        include:
+          # OSs not already tested above
+          - os: ubuntu-18.04
+            artifact_name: capa
+            asset_name: linux
+          - os: ubuntu-20.04
+            artifact_name: capa
+            asset_name: linux
+          - os: windows-2016
+            artifact_name: capa.exe
+            asset_name: windows
+    steps:
+      - name: Download ${{ matrix.asset_name }}
+        uses: actions/download-artifact@v2
+        with:
+          name: ${{ matrix.asset_name }}
+      - name: Set executable flag
+        if: matrix.os != 'windows-2016'
+        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: 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 }}
+>>>>>>> master

.github/workflows/publish.yml

@@ -9,13 +9,13 @@ on:
 
 jobs:
   deploy:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: '2.7'
+          python-version: '3.6'
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
@@ -27,3 +27,4 @@ jobs:
         run: |
           python setup.py sdist bdist_wheel
           twine upload --skip-existing dist/*
+

.github/workflows/tag.yml

@@ -0,0 +1,29 @@
+name: tag
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  tag:
+    name: Tag capa rules
+    runs-on: ubuntu-20.04
+    steps:
+    - name: Checkout capa-rules
+      uses: actions/checkout@v2
+      with:
+        repository: fireeye/capa-rules
+        token: ${{ secrets.CAPA_TOKEN }}
+    - name: Tag capa-rules
+      run: |
+        # user information is needed to create annotated tags (with a message)
+        git config user.email 'capa-dev@fireeye.com'
+        git config user.name 'Capa Bot'
+        name=${{ github.event.release.tag_name }}
+        git tag $name -m "https://github.com/fireeye/capa/releases/$name"
+    - name: Push tag to capa-rules
+      uses: ad-m/github-push-action@master
+      with:
+        repository: fireeye/capa-rules
+        github_token: ${{ secrets.CAPA_TOKEN }}
+        tags: true

.github/workflows/tests.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   code_style:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
     - name: Checkout capa
       uses: actions/checkout@v2
@@ -17,14 +17,14 @@ jobs:
       with:
         python-version: 3.8
     - name: Install dependencies
-      run: pip install 'isort==5.*' black
+      run: pip install -e .[dev]
     - name: Lint with isort
       run: isort --profile black --length-sort --line-width 120 -c .
     - name: Lint with black
       run: black -l 120 --check .
 
   rule_linter:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
     - name: Checkout capa with rules submodule
       uses: actions/checkout@v2
@@ -34,37 +34,43 @@ jobs:
       uses: actions/setup-python@v2
       with:
         python-version: 3.8
-    # We don't need vivisect, so we can install capa using Python3
     - name: Install capa
       run: pip install -e .
     - name: Run rule linter
       run: python scripts/lint.py rules/
 
   tests:
-    name: Tests in ${{ matrix.python }}
+    name: Tests in ${{ matrix.python-version }} on ${{ matrix.os }}
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     needs: [code_style, rule_linter]
     strategy:
       fail-fast: false
       matrix:
+        os: [ubuntu-20.04, windows-2019, macos-10.15]
+        # across all operating systems
+        python-version: [3.6, 3.9]
         include:
-          - python: 2.7
+          # on Ubuntu run these as well
-          - python: 3.7
+          - os: ubuntu-20.04
-          - python: 3.8
+            python-version: 3.7
-          - python: 3.9.1
+          - os: ubuntu-20.04
+            python-version: 3.8
     steps:
     - name: Checkout capa with submodules
       uses: actions/checkout@v2
       with:
         submodules: true
-    - name: Set up Python ${{ matrix.python }}
+    - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v2
       with:
-        python-version: ${{ matrix.python }}
+        python-version: ${{ matrix.python-version }}
     - name: Install pyyaml
+      if: matrix.os == 'ubuntu-20.04'
       run: sudo apt-get install -y libyaml-dev
+    - name: Install Microsoft Visual C++ 9.0
+      if: matrix.os == 'windows-2019' && matrix.python-version == '2.7'
+      run: choco install vcpython27
     - name: Install capa
       run: pip install -e .[dev]
     - name: Run tests
       run: pytest tests/
-

CHANGELOG.md

@@ -1,5 +1,204 @@
 # Change Log
 
+## master (unreleased)
+
+The first Python 3 ONLY capa version.
+
+### New Features
+
+- main: auto detect shellcode based on file extension #516 @mr-tz
+
+### New Rules
+
+### Bug Fixes
+
+- build: use Python 3.8 for PyInstaller to support consistently running across multiple operating systems including Windows 7 #505 @mr-tz
+
+### Changes
+
+- py3: drop Python 2 support #480 @Ana06
+- deps: bump ruamel yaml parser to 0.17.4 #519 @williballenthin
+- explorer: explain how to install IDA 7.6 patch to enable the plugin #528 @williballenthin
+
+### Development
+
+- ci: add capa release link to capa-rules tag #517 @Ana06
+
+### Raw diffs
+
+<!-- The diff uses v1.6.1 because master doesn't include v1.6.2 -->
+- [capa v1.6.1...master](https://github.com/fireeye/capa/compare/v1.6.1...master)
+- [capa-rules v1.6.1...master](https://github.com/fireeye/capa-rules/compare/v1.6.1...master)
+
+
+## v1.6.2 (2021-04-13)
+
+This release backports a fix to capa 1.6: The Windows binary was built with Python 3.9 which doesn't support Windows 7.
+
+### Bug Fixes
+
+- build: use Python 3.8 for PyInstaller to support consistently running across multiple operating systems including Windows 7 @mr-tz @Ana06
+
+### Raw diffs
+
+  - [capa v1.6.1...v1.6.2](https://github.com/fireeye/capa/compare/v1.6.1...v1.6.2)
+  - [capa-rules v1.6.1...v1.6.2](https://github.com/fireeye/capa-rules/compare/v1.6.1...v1.6.2)
+
+## v1.6.1 (2021-04-07)
+
+This release includes several bug fixes, such as a vivisect issue that prevented capa from working on Windows with Python 3. It also adds 17 new rules and a bunch of improvements in the rules and IDA rule generator. We appreciate everyone who opened issues, provided feedback, and contributed code and rules.
+
+### Upcoming changes
+
+**This is the very last capa release that supports Python 2.** The next release will be v2.0 and will have breaking changes, including the removal of Python 2 support.
+
+### New features
+
+- explorer: add support for multi-line tab and SHIFT + Tab #474 @mike-hunhoff
+
+![multi-line tab in rule generator](doc/img/changelog/tab.gif)
+
+### New Rules (17)
+
+- encrypt data using RC4 with custom key via WinAPI @MalwareMechanic
+- encrypt data using Curve25519 @dandonov
+- packaged as an IExpress self-extracting archive @recvfrom
+- create registry key via offline registry library @johnk3r
+- open registry key via offline registry library @johnk3r
+- query registry key via offline registry library @johnk3r
+- set registry key via offline registry library @johnk3r
+- delete registry key via offline registry library @johnk3r
+- enumerate PE sections @Ana06
+- inject DLL reflectively @Ana06
+- inspect section memory permissions @Ana06
+- parse PE exports @Ana06
+- rebuild import table @Ana06
+- compare security identifiers @mike-hunhoff
+- get user security identifier @mike-hunhoff
+- listen for remote procedure calls @mike-hunhoff
+- query remote server for available data @mike-hunhoff
+
+### Bug Fixes
+
+- vivisect: update to v1.0.1 which includes bug fix for #459 (capa failed in Windows with Python 3 and vivisect) #512 @williballenthin
+- explorer: fix initialize rules directory #464 @mike-hunhoff
+- explorer: support subscope rules #493 @mike-hunhoff
+- explorer: add checks to validate matched data when searching #500 @mike-hunhoff
+- features, explorer: add support for string features with special characters e.g. '\n' #468 @mike-hunhoff
+
+### Changes
+
+- vivisect: raises `IncompatibleVivVersion` instead of `UnicodeDecodeError` when using incompatible Python 2 `.viv` files with Python3 #479 @Ana06
+- explorer: improve settings modification #465 @mike-hunhoff
+- rules: improvements @mr-tz, @re-fox, @mike-hunhoff
+- rules, lint: enforce string with double quotes formatting in rules #468 @mike-hunhoff
+- lint: ensure LF end of line #485 #486 @mr-tz
+- setup: pin dependencies #513 #504 @Ana06 @mr-tz
+
+### Development
+
+- ci: test on Windows, Ubuntu, macOS across Python versions #470 @mr-tz @Ana06
+- ci: pin OS versions #491 @williballenthin
+- ci: tag capa-rules on release #476 @Ana06
+- doc: document release process #476 @Ana06
+- doc: Improve README badges #477 #478 @ana06 @mr-tz
+- doc: update capa explorer documentation #503 @mike-hunhoff
+- doc: add PR template #495 @mr-tz
+- changelog: document incompatibility of viv files #475 @Ana06
+- rule loading: ignore files starting with .git #492 @mr-tz
+
+### Raw diffs
+
+  - [capa v1.6.0...v1.6.1](https://github.com/fireeye/capa/compare/v1.6.0...v1.6.1)
+  - [capa-rules v1.6.0...v1.6.1](https://github.com/fireeye/capa-rules/compare/v1.6.0...v1.6.1)
+
+
+## v1.6.0 (2021-03-09)
+
+This release adds the capa explorer rule generator plugin for IDA Pro, vivisect support for Python 3 and 12 new rules. We appreciate everyone who opened issues, provided feedback, and contributed code and rules. Thank you also to the vivisect development team (@rakuy0, @atlas0fd00m) for the Python 3 support (`vivisect==1.0.0`) and the fixes for Python 2 (`vivisect==0.2.1`).
+
+### Rule Generator IDA Plugin
+
+The capa explorer IDA plugin now helps you quickly build new capa rules using features extracted directly from your IDA database. Without leaving the plugin interface you can use the features extracted by capa explorer to develop and test new rules and save your work directly to your capa rules directory. To get started select the new `Rule Generator` tab, navigate to a function in the IDA `Disassembly` view, and click `Analyze`. For more information check out the capa explorer [readme](https://github.com/fireeye/capa/blob/master/capa/ida/plugin/README.md).
+
+![](doc/img/rulegen_expanded.png)
+
+### Python 2/3 vivisect workspace compatibility
+
+This version of capa adds Python 3 support in vivisect. Note that `.viv` files (generated by vivisect) are not compatible between Python 2 and Python 3. When updating to Python 3 you need to delete all the `.viv` files for capa to work.
+
+If you get the following error (or a similar one), you most likely need to delete `.viv` files:
+```
+UnicodeDecodeError: 'ascii' codec can't decode byte 0x90 in position 2: ordinal not in range(128)
+```
+
+### Upcoming changes
+
+**This is the last capa release that supports Python 2.** The next release will be v2.0 and will have breaking changes, including the removal of Python 2 support.
+
+If you have workflows that rely on the Python 2 version and need future maintenance, please reach out. We may be able to supply limited backports of key fixes and features.
+
+### New features
+
+- explorer: Add capa explorer rule generator plugin for IDA Pro. Now capa explorer helps you build new capa rules!  #426, #438, #439 @mike-hunhoff
+- python: Python 3 support in vivisect #421 @Ana06
+- main: Add backend option in Python 3 to select the backend to be used (either SMDA or vivisect) #421 @Ana06
+- python: Python 3 support in IDA #429, #437 @mike-hunhoff
+- ci: test pyinstaller CI #452 @williballenthin
+- scripts: enable multiple backends in `show-features.py` #429 @mike-hunhoff
+- scripts: add `scripts/vivisect-py2-vs-py3.sh`  to compare vivisect Python 2 vs 3 (can easily be modified to test run times and compare different versions) #421 @Ana06
+
+### New Rules (12)
+
+- patch process command line @re-fox @williballenthin (graduated from nursery)
+- compiled with dmd @re-fox
+- compiled with exe4j @johnk3r
+- compiled from Visual Basic @williballenthin
+- capture screenshot in Go @TcM1911
+- compiled with Nim @mike-hunhoff
+- linked against Go process enumeration library @TcM1911
+- linked against Go registry library @TcM1911
+- linked against Go WMI library @TcM1911
+- linked against Go static asset library @TcM1911
+- inspect load icon resource @mike-hunhoff
+- linked against XZip @mr-tz
+
+### Bug Fixes
+
+- ida: check for unmapped addresses when resolving data references #436 @mike-hunhoff
+
+### Changes
+
+- setup: vivisect v1.0.0 is the default backend for Python3 (it was SMDA before) #421 @Ana06
+- setup: bump vivisect to 0.2.1 #454 @mr-tz
+- linter: adding ntoskrnl, ntdll overlap lint #428 @mike-hunhoff
+- ci: use py3.9 and pyinstaller 4.2 to build standalone binaries #452 @williballenthin
+- scripts: remove old migration script #450 @williballenthin
+
+### Development
+
+- main: factor out common cli argument handling #450 @williballenthin
+
+### Raw diffs
+
+  - [capa v1.5.1...v1.6.0](https://github.com/fireeye/capa/compare/v1.5.1...v1.6.0)
+  - [capa-rules v1.5.1...v1.6.0](https://github.com/fireeye/capa-rules/compare/v1.5.1...v1.6.0)
+
+
+## v1.5.1 (2021-02-09)
+
+This release fixes the version number that we forgot to update for v1.5.0 (therefore, v1.5.0 was not published to pypi). It also includes 1 new rule and some rule improvements.
+
+### New Rules (1)
+
+- encrypt data using vest @re-fox
+
+### Raw diffs
+
+  - [capa v1.5.0...v1.5.1](https://github.com/fireeye/capa/compare/v1.5.1...v1.6.0)
+  - [capa-rules v1.5.0...v1.5.1](https://github.com/fireeye/capa-rules/compare/v1.5.1...v1.6.0)
+
+
 ## v1.5.0 (2021-02-05)
 
 This release brings support for running capa under Python 3 via [SMDA](https://github.com/danielplohmann/smda), more thorough CI testing and linting, better extraction of strings and byte features, and 50 (!) new rules. We appreciate everyone who opened issues, provided feedback, and contributed code and rules. A special shout out to the following new project contributors:

README.md

@@ -1,7 +1,10 @@
 ![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/fireeye/capa)](https://github.com/fireeye/capa/releases)
+[![Number of rules](https://img.shields.io/badge/rules-488-blue.svg)](https://github.com/fireeye/capa-rules)
 [![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-469-blue.svg)](https://github.com/fireeye/capa-rules)
+[![Downloads](https://img.shields.io/github/downloads/fireeye/capa/total)](https://github.com/fireeye/capa/releases)
 [![License](https://img.shields.io/badge/license-Apache--2.0-green.svg)](LICENSE.txt)
 
 capa detects capabilities in executable files.
@@ -146,8 +149,8 @@ rule:
 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 plugin](capa/ida/plugin/).
+If you use IDA Pro, then you can use the [capa explorer](capa/ida/plugin/) plugin.
-capa explorer lets you quickly identify and navigate to interesting areas of a program and help you build new capa rules out of the features extracted directly from your IDB.
+capa explorer helps you identify interesting areas of a program and build new capa rules using features extracted directly from your IDA Pro database.
 
 ![capa + IDA Pro integration](doc/img/explorer_expanded.png)
 

capa/features/__init__.py

@@ -27,17 +27,28 @@ 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"))
-        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" """
+    """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):
+    """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 Feature(object):
     def __init__(self, value, arch=None, description=None):
         """

capa/features/extractors/helpers.py

@@ -16,10 +16,7 @@ MIN_STACKSTRING_LEN = 8
 
 
 def xor_static(data, i):
-    if sys.version_info >= (3, 0):
+    return bytes(c ^ i for c in data)
-        return bytes(c ^ i for c in data)
-    else:
-        return "".join(chr(ord(c) ^ i) for c in data)
 
 
 def is_aw_function(symbol):

capa/features/extractors/ida/__init__.py

@@ -34,10 +34,7 @@ def add_ea_int_cast(o):
     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))
-        setattr(o, "__int__", types.MethodType(get_ea, o))
-    else:
-        setattr(o, "__int__", types.MethodType(get_ea, o, type(o)))
     return o
 
 

capa/features/extractors/ida/basicblock.py

@@ -39,18 +39,11 @@ def get_printable_len(op):
         raise ValueError("Unhandled operand data type 0x%x." % op.dtype)
 
     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)
-            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 sys.version_info[0] >= 3:
+        if all(c == 0x00 for c in chars[1::2]):
-            if all(c == 0x00 for c in chars[1::2]):
+            return is_printable_ascii(chars[::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)

capa/features/extractors/ida/file.py

@@ -78,7 +78,7 @@ def extract_file_embedded_pe():
 
 
 def extract_file_export_names():
-    """ extract function exports """
+    """extract function exports"""
     for (_, _, ea, name) in idautils.Entries():
         yield Export(name), ea
 
@@ -144,7 +144,7 @@ def extract_file_strings():
 
 
 def extract_features():
-    """ extract file features """
+    """extract file features"""
     for file_handler in FILE_HANDLERS:
         for feature, va in file_handler():
             yield feature, va

capa/features/extractors/ida/helpers.py

@@ -23,11 +23,7 @@ def find_byte_sequence(start, end, seq):
         end: max virtual address
         seq: bytes to search e.g. b"\x01\x03"
     """
-    if sys.version_info[0] >= 3:
+    seq = " ".join(["%02x" % b for b in seq])
-        seq = " ".join(["%02x" % b for b in seq])
-    else:
-        seq = " ".join(["%02x" % ord(b) for b in seq])
-
     while True:
         ea = idaapi.find_binary(start, end, seq, 0, idaapi.SEARCH_DOWN)
         if ea == idaapi.BADADDR:
@@ -83,7 +79,7 @@ def get_segment_buffer(seg):
 
 
 def get_file_imports():
-    """ get file imports """
+    """get file imports"""
     imports = {}
 
     for idx in range(idaapi.get_import_module_qty()):
@@ -120,7 +116,7 @@ def get_instructions_in_range(start, end):
 
 
 def is_operand_equal(op1, op2):
-    """ compare two IDA op_t """
+    """compare two IDA op_t"""
     if op1.flags != op2.flags:
         return False
 
@@ -146,7 +142,7 @@ def is_operand_equal(op1, op2):
 
 
 def is_basic_block_equal(bb1, bb2):
-    """ compare two IDA BasicBlock """
+    """compare two IDA BasicBlock"""
     if bb1.start_ea != bb2.start_ea:
         return False
 
@@ -160,7 +156,7 @@ def is_basic_block_equal(bb1, bb2):
 
 
 def basic_block_size(bb):
-    """ calculate size of basic block """
+    """calculate size of basic block"""
     return bb.end_ea - bb.start_ea
 
 
@@ -178,7 +174,7 @@ def read_bytes_at(ea, count):
 
 
 def find_string_at(ea, min=4):
-    """ check if ASCII string exists at a given virtual address """
+    """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:
         try:
@@ -232,23 +228,23 @@ def get_op_phrase_info(op):
 
 
 def is_op_write(insn, op):
-    """ Check if an operand is written to (destination operand) """
+    """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, op):
-    """ Check if an operand is read from (source operand) """
+    """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, op):
-    """ Check is an operand has been marked as an offset (by auto-analysis or manually) """
+    """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):
-    """ determine if instruction modifies SP, ESP, RSP """
+    """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
@@ -257,7 +253,7 @@ def is_sp_modified(insn):
 
 
 def is_bp_modified(insn):
-    """ check if instruction modifies BP, EBP, RBP """
+    """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
@@ -266,12 +262,12 @@ def is_bp_modified(insn):
 
 
 def is_frame_register(reg):
-    """ check if register is sp or bp """
+    """check if register is sp or bp"""
     return reg in (idautils.procregs.sp.reg, idautils.procregs.bp.reg)
 
 
 def get_insn_ops(insn, target_ops=()):
-    """ yield op_t for instruction, filter on type if specified """
+    """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
@@ -282,7 +278,7 @@ def get_insn_ops(insn, target_ops=()):
 
 
 def is_op_stack_var(ea, index):
-    """ check if operand is a stack variable """
+    """check if operand is a stack variable"""
     return idaapi.is_stkvar(idaapi.get_flags(ea), index)
 
 
@@ -336,7 +332,7 @@ def is_basic_block_tight_loop(bb):
 
 
 def find_data_reference_from_insn(insn, max_depth=10):
-    """ search for data reference from instruction, return address of instruction if no reference exists """
+    """search for data reference from instruction, return address of instruction if no reference exists"""
     depth = 0
     ea = insn.ea
 
@@ -379,5 +375,5 @@ def get_function_blocks(f):
 
 
 def is_basic_block_return(bb):
-    """ check if basic block is return block """
+    """check if basic block is return block"""
     return bb.type == idaapi.fcb_ret

capa/features/extractors/ida/insn.py

@@ -53,7 +53,7 @@ def get_imports(ctx):
 
 
 def check_for_api_call(ctx, insn):
-    """ check instruction for API call """
+    """check instruction for API call"""
     if not insn.get_canon_mnem() in ("call", "jmp"):
         return
 
@@ -256,7 +256,7 @@ def bb_stack_cookie_registers(bb):
 
 
 def is_nzxor_stack_cookie_delta(f, bb, insn):
-    """ check if nzxor exists within stack cookie delta """
+    """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
@@ -279,7 +279,7 @@ def is_nzxor_stack_cookie_delta(f, bb, insn):
 
 
 def is_nzxor_stack_cookie(f, bb, insn):
-    """ check if nzxor is related to stack cookie """
+    """check if nzxor is related to stack cookie"""
     if contains_stack_cookie_keywords(idaapi.get_cmt(insn.ea, False)):
         # Example:
         #   xor     ecx, ebp        ; StackCookie

capa/features/extractors/smda/__init__.py

@@ -15,8 +15,6 @@ 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
 

capa/features/extractors/smda/basicblock.py

@@ -15,7 +15,7 @@ def _bb_has_tight_loop(f, bb):
 
 
 def extract_bb_tight_loop(f, bb):
-    """ check basic block for tight loop indicators """
+    """check basic block for tight loop indicators"""
     if _bb_has_tight_loop(f, bb):
         yield Characteristic("tight loop"), bb.offset
 
@@ -39,7 +39,7 @@ def get_operands(smda_ins):
 
 
 def extract_stackstring(f, bb):
-    """ check basic block for stackstring indicators """
+    """check basic block for stackstring indicators"""
     if _bb_has_stackstring(f, bb):
         yield Characteristic("stack string"), bb.offset
 

capa/features/extractors/smda/insn.py

@@ -293,7 +293,7 @@ def extract_insn_peb_access_characteristic_features(f, bb, insn):
 
 
 def extract_insn_segment_access_features(f, bb, insn):
-    """ parse the instruction for access to fs or gs """
+    """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:

capa/features/extractors/viv/basicblock.py

@@ -45,7 +45,7 @@ def _bb_has_tight_loop(f, bb):
 
 
 def extract_bb_tight_loop(f, bb):
-    """ check basic block for tight loop indicators """
+    """check basic block for tight loop indicators"""
     if _bb_has_tight_loop(f, bb):
         yield Characteristic("tight loop"), bb.va
 
@@ -68,7 +68,7 @@ def _bb_has_stackstring(f, bb):
 
 
 def extract_stackstring(f, bb):
-    """ check basic block for stackstring indicators """
+    """check basic block for stackstring indicators"""
     if _bb_has_stackstring(f, bb):
         yield Characteristic("stack string"), bb.va
 

capa/features/extractors/viv/insn.py

@@ -486,7 +486,7 @@ def extract_insn_peb_access_characteristic_features(f, bb, insn):
 
 
 def extract_insn_segment_access_features(f, bb, insn):
-    """ parse the instruction for access to fs or gs """
+    """parse the instruction for access to fs or gs"""
     prefix = insn.getPrefixName()
 
     if prefix == "fs":

capa/features/freeze.py

@@ -264,15 +264,14 @@ def main(argv=None):
     parser.add_argument(
         "-f", "--format", choices=[f[0] for f in formats], default="auto", help="Select sample format, %s" % format_help
     )
-    if sys.version_info >= (3, 0):
+    parser.add_argument(
-        parser.add_argument(
+        "-b",
-            "-b",
+        "--backend",
-            "--backend",
+        type=str,
-            type=str,
+        help="select the backend to use",
-            help="select the backend to use",
+        choices=(capa.main.BACKEND_VIV, capa.main.BACKEND_SMDA),
-            choices=(capa.main.BACKEND_VIV, capa.main.BACKEND_SMDA),
+        default=capa.main.BACKEND_VIV,
-            default=capa.main.BACKEND_VIV,
+    )
-        )
     parser.add_argument(
         "--signature",
         action="append",
@@ -293,8 +292,7 @@ def main(argv=None):
         logging.basicConfig(level=logging.INFO)
         logging.getLogger().setLevel(logging.INFO)
 
-    backend = args.backend if sys.version_info > (3, 0) else capa.main.BACKEND_VIV
+    extractor = capa.main.get_extractor(args.sample, args.format, args.backend, sigpaths=args.signatures)
-    extractor = capa.main.get_extractor(args.sample, args.format, backend, sigpaths=args.signatures)
     with open(args.output, "wb") as f:
         f.write(dump(extractor))
 

capa/helpers.py

@@ -12,9 +12,7 @@ _hex = hex
 
 
 def hex(i):
-    # under py2.7, long integers get formatted with a trailing `L`
+    return _hex(oint(i))
-    # and this is not pretty. so strip it out.
-    return _hex(oint(i)).rstrip("L")
 
 
 def oint(i):

capa/ida/helpers/__init__.py

@@ -10,7 +10,6 @@ import logging
 import datetime
 
 import idc
-import six
 import idaapi
 import idautils
 
@@ -24,6 +23,7 @@ SUPPORTED_IDA_VERSIONS = [
     "7.3",
     "7.4",
     "7.5",
+    "7.6",
 ]
 
 # file type names as returned by idaapi.get_file_type_name()
@@ -71,7 +71,7 @@ def get_disasm_line(va):
 
 
 def is_func_start(ea):
-    """ check if function stat exists at virtual address """
+    """check if function stat exists at virtual address"""
     f = idaapi.get_func(ea)
     return f and f.start_ea == ea
 
@@ -85,7 +85,7 @@ def get_func_start_ea(ea):
 def get_file_md5():
     """ """
     md5 = idautils.GetInputFileMD5()
-    if not isinstance(md5, six.string_types):
+    if not isinstance(md5, str):
         md5 = capa.features.bytes_to_str(md5)
     return md5
 
@@ -93,7 +93,7 @@ def get_file_md5():
 def get_file_sha256():
     """ """
     sha256 = idaapi.retrieve_input_file_sha256()
-    if not isinstance(sha256, six.string_types):
+    if not isinstance(sha256, str):
         sha256 = capa.features.bytes_to_str(sha256)
     return sha256
 

capa/ida/plugin/README.md

@@ -1,13 +1,12 @@
 ![capa explorer](../../../.github/capa-explorer-logo.png)
 
-capa explorer is an IDA Pro plugin written in Python that integrates the FLARE team's open-source framework, capa, with IDA. capa is a framework that uses a well-defined collection of rules to 
+capa explorer is an IDAPython plugin that integrates the FLARE team's open-source framework, capa, with IDA Pro. capa is a framework that uses a well-defined collection of rules to 
 identify capabilities in a program. You can run capa against a PE file or shellcode and it tells you what it thinks the program can do. For example, it might suggest that 
-the program is a backdoor, can install services, or relies on HTTP to communicate. You can use capa explorer to run capa directly on an IDA database without requiring access
+the program is a backdoor, can install services, or relies on HTTP to communicate. capa explorer runs capa directly against your IDA Pro database (IDB) without requiring access
-to or execution of the source binary. Once a database has been analyzed, capa explorer can be used to quickly identify and navigate to interesting areas of a program and manually build new capa rules out
+to the original binary file. Once a database has been analyzed, capa explorer helps you identify interesting areas of a program and build new capa rules using features extracted from your IDB.
-of the features extracted directly from your IDB.
 
 We love using capa explorer during malware analysis because it teaches us what parts of a program suggest a behavior. As we click on rows, capa explorer jumps directly 
-to important addresses in the IDA Pro database and highlights key features in the Disassembly view so they stand out visually. To illustrate, we use capa explorer to 
+to important addresses in the IDB and highlights key features in the Disassembly view so they stand out visually. To illustrate, we use capa explorer to 
 analyze Lab 14-02 from [Practical Malware Analysis](https://nostarch.com/malware) (PMA) available [here](https://practicalmalwareanalysis.com/labs/). Our goal is to understand 
 the program's functionality.
 
@@ -15,16 +14,15 @@ After loading Lab 14-02 into IDA and analyzing the database with capa explorer,
 
 ![](../../../doc/img/explorer_condensed.png)
 
-We can use capa explorer to navigate the IDA Disassembly view directly to the suspect function and get an assembly-level breakdown of why capa matched `self delete via COMSPEC environment variable` 
+We can use capa explorer to navigate our Disassembly view directly to the suspect function and get an assembly-level breakdown of why capa matched `self delete via COMSPEC environment variable`.
-for this particular function.
 
 ![](../../../doc/img/explorer_expanded.png)
 
 Using the `Rule Information` and `Details` columns capa explorer shows us that the suspect function matched `self delete via COMSPEC environment variable` because it contains capa rule matches for `create process`, `get COMSPEC environment variable`,
-and `query environment variable`, references to the strings `COMSPEC`, ` > nul`, and `/c del`, and calls to the Windows API functions `GetEnvironmentVariableA` and `ShellExecuteEx`.
+and `query environment variable`, references to the strings `COMSPEC`, ` > nul`, and `/c del `, and calls to the Windows API functions `GetEnvironmentVariableA` and `ShellExecuteEx`.
 
-capa explorer also helps you build new capa rules. To start select the `Rule Generator` tab, navigate to a function in the IDA `Disassembly` view,
+capa explorer also helps you build new capa rules. To start select the `Rule Generator` tab, navigate to a function in your Disassembly view,
-and click `Analyze`. capa explorer will extract features from this function and display them in the `Function Features` pane. You can add features listed in this pane to the `Editor` pane
+and click `Analyze`. capa explorer will extract features from the function and display them in the `Features` pane. You can add features listed in this pane to the `Editor` pane
 by either double-clicking a feature or using multi-select + right-click to add multiple features at once. The `Preview` and `Editor` panes help edit your rule. Use the `Preview` pane
 to modify the rule text directly and the `Editor` pane to construct and rearrange your hierarchy of statements and features. When you finish a rule you can save it directly to a file by clicking `Save`.
 
@@ -36,15 +34,32 @@ For more information on the FLARE team's open-source framework, capa, check out
 
 ### Requirements
 
-capa explorer supports the following IDA setups:
+capa explorer supports Python >= 3.6 and the following IDA Pro versions:
 
-* IDA Pro 7.4+ with Python 2.7 or Python 3.
+* IDA 7.4
+* IDA 7.5
+* IDA 7.6 (caveat below)
 
 If you encounter issues with your specific setup, please open a new [Issue](https://github.com/fireeye/capa/issues).
 
+#### IDA 7.6 caveat: IDA needs a patch
+
+As described [here](https://www.hex-rays.com/blog/ida-7-6-empty-qtreeview-qtreewidget/):
+
+> A rather nasty issue evaded our testing and found its way into IDA 7.6: using the PyQt5 modules that are shipped with IDA, QTreeView (or QTreeWidget) instances will always fail to display contents.
+
+Therefore, in order to use capa under IDA 7.6, you need to download and install the fix corresponding to your IDA installation, replacing the original QtWidgets DLL with the one contained in the .zip file (links to Hex-Rays):
+
+
+  - Windows: [pyqt5_qtwidgets_win](https://www.hex-rays.com/wp-content/uploads/2021/04/pyqt5_qtwidgets_win.zip)
+  - Linux: [pyqt5_qtwidgets_linux](https://www.hex-rays.com/wp-content/uploads/2021/04/pyqt5_qtwidgets_linux.zip)
+  - MacOS (Intel): [pyqt5_qtwidgets_mac_x64](https://www.hex-rays.com/wp-content/uploads/2021/04/pyqt5_qtwidgets_mac_x64.zip)
+  - MacOS (AppleSilicon): [pyqt5_qtwidgets_mac_arm](https://www.hex-rays.com/wp-content/uploads/2021/04/pyqt5_qtwidgets_mac_arm.zip)
+
+
 ### Supported File Types
 
-capa explorer is limited to the file types supported by capa, which includes:
+capa explorer is limited to the file types supported by capa, which include:
 
 * Windows 32-bit and 64-bit PE files
 * Windows 32-bit and 64-bit shellcode
@@ -62,50 +77,48 @@ You can install capa explorer using the following steps:
 
 ### Usage
 
-1. Run IDA and analyze a supported file type (select the `Manual Load` and `Load Resources` options in IDA for best results)
+1. Open IDA and analyze a supported file type (select the `Manual Load` and `Load Resources` options in IDA for best results)
 2. Open capa explorer in IDA by navigating to `Edit > Plugins > FLARE capa explorer` or using the keyboard shortcut `Alt+F5`
 3. Select the `Program Analysis` tab
 4. Click the `Analyze` button
 
 When running capa explorer for the first time you are prompted to select a file directory containing capa rules. The plugin conveniently
-remembers your selection for future runs; you can change this selection by navigating to `Settings > Change default rules directory...`. We recommend 
+remembers your selection for future runs; you can change this selection and other default settings by clicking `Settings`. We recommend 
 downloading and using the [standard collection of capa rules](https://github.com/fireeye/capa-rules) when getting started with the plugin.
 
 #### Tips for Program Analysis
 
 * Start analysis by clicking the `Analyze` button
-* Reset the plugin user interface and remove highlighting from IDA disassembly view by clicking the `Reset` button
+* Reset the plugin user interface and remove highlighting from your Disassembly view by clicking the `Reset` button
-* Change your capa rules directory by navigating to `Settings > Change default rules directory...` from the plugin menu
+* Change your capa rules directory and other default settings by clicking `Settings`
 * Hover your cursor over a rule match to view the source content of the rule
-* Double-click the `Address` column to navigate the IDA Disassembly view to the associated feature
+* Double-click the `Address` column to navigate your Disassembly view to the address of the associated feature
 * Double-click a result in the `Rule Information` column to expand its children
-* Select a checkbox in the `Rule Information` column to highlight the address of the associated feature in the IDA Dissasembly view
+* Select a checkbox in the `Rule Information` column to highlight the address of the associated feature in your Dissasembly view
 
 #### Tips for Rule Generator
 
-* Navigate to a function in the `Disassembly` view and click`Analyze` to get started
+* Navigate to a function in your Disassembly view and click`Analyze` to get started
-* Double-click or multi-select + right-click in the `Function Features` pane to add features to the `Editor` pane
+* Double-click or use multi-select + right-click to add features from the `Features` pane to the `Editor` pane
-* Right-click features in the `Editor` pane to make modifications
+* Right-click features in the `Editor` pane to make context-specific modifications
-* Drag-and-drop (single click + multi-select support) features in the `Editor` pane to quickly build a hierarchy of statements and features
+* Drag-and-drop (single click + multi-select support) features in the `Editor` pane to construct your hierarchy of statements and features
-* Right-click anywhere in the `Editor` pane not on a feature to quickly remove all features
+* Right-click anywhere in the `Editor` pane not on a feature to remove all features
-* Add descriptions/comments by placing editing the appropriate column in the `Editor` pane
+* Add descriptions or comments to a feature by editing the corresponding column in the `Editor` pane
-* Directly edit rule text, including rule metadata fields using the `Preview` pane
+* Directly edit rule text and metadata fields using the `Preview` pane
-* Change the default rule author and default scope displayed in the `Preview` pane by navigating to `Settings`
+* Change the default rule author and default rule scope displayed in the `Preview` pane by clicking `Settings`
 
 ## Development
 
-Because capa explorer is packaged with capa you will need to install capa locally for development.
+capa explorer is packaged with capa so you will need to install capa locally for development. You can install capa locally by following the steps outlined in `Method 3: Inspecting the capa source code` of the [capa 
-
-You can install capa locally by following the steps outlined in `Method 3: Inspecting the capa source code` of the [capa 
 installation guide](https://github.com/fireeye/capa/blob/master/doc/installation.md#method-3-inspecting-the-capa-source-code). Once installed, copy [capa_explorer.py](https://raw.githubusercontent.com/fireeye/capa/master/capa/ida/plugin/capa_explorer.py) 
-to your IDA plugins directory to run the plugin in IDA.
+to your plugins directory to install capa explorer in IDA.
 
 ### Components
 
 capa explorer consists of two main components:
 
-* An IDA [feature extractor](https://github.com/fireeye/capa/tree/master/capa/features/extractors/ida) built on top of IDA's binary analysis engine
+* An [feature extractor](https://github.com/fireeye/capa/tree/master/capa/features/extractors/ida) built on top of IDA's binary analysis engine
-  * This component uses IDAPython to extract [capa features](https://github.com/fireeye/capa-rules/blob/master/doc/format.md#extracted-features) from the IDA database such as strings, 
+  * This component uses IDAPython to extract [capa features](https://github.com/fireeye/capa-rules/blob/master/doc/format.md#extracted-features) from your IDBs such as strings, 
 disassembly, and control flow; these extracted features are used by capa to find feature combinations that result in a rule match
 * An [interactive user interface](https://github.com/fireeye/capa/tree/master/capa/ida/plugin) for displaying and exploring capa rule matches
-  * This component integrates the IDA feature extractor and capa, providing an interactive user interface to dissect rule matches found by capa using features extracted by the IDA feature extractor
+  * This component integrates the feature extractor and capa, providing an interactive user interface to dissect rule matches found by capa using features extracted directly from your IDBs

capa/ida/plugin/form.py

@@ -37,6 +37,10 @@ from capa.ida.plugin.proxy import CapaExplorerRangeProxyModel, CapaExplorerSearc
 logger = logging.getLogger(__name__)
 settings = ida_settings.IDASettings("capa")
 
+CAPA_SETTINGS_RULE_PATH = "rule_path"
+CAPA_SETTINGS_RULEGEN_AUTHOR = "rulegen_author"
+CAPA_SETTINGS_RULEGEN_SCOPE = "rulegen_scope"
+
 
 def write_file(path, data):
     """ """
@@ -166,6 +170,60 @@ class CapaExplorerFeatureExtractor(capa.features.extractors.ida.IdaFeatureExtrac
         return super(CapaExplorerFeatureExtractor, self).extract_function_features(f)
 
 
+class QLineEditClicked(QtWidgets.QLineEdit):
+    def __init__(self, content, parent=None):
+        """ """
+        super(QLineEditClicked, self).__init__(content, parent)
+
+    def mouseReleaseEvent(self, e):
+        """ """
+        old = self.text()
+        new = str(
+            QtWidgets.QFileDialog.getExistingDirectory(
+                self.parent(), "Please select a capa rules directory", settings.user.get(CAPA_SETTINGS_RULE_PATH, "")
+            )
+        )
+        if new:
+            self.setText(new)
+        else:
+            self.setText(old)
+
+
+class CapaSettingsInputDialog(QtWidgets.QDialog):
+    def __init__(self, title, parent=None):
+        """ """
+        super(CapaSettingsInputDialog, self).__init__(parent)
+
+        self.setWindowTitle(title)
+        self.setMinimumWidth(500)
+        self.setWindowFlags(self.windowFlags() & ~QtCore.Qt.WindowContextHelpButtonHint)
+
+        self.edit_rule_path = QLineEditClicked(settings.user.get(CAPA_SETTINGS_RULE_PATH, ""))
+        self.edit_rule_author = QtWidgets.QLineEdit(settings.user.get(CAPA_SETTINGS_RULEGEN_AUTHOR, ""))
+        self.edit_rule_scope = QtWidgets.QComboBox()
+
+        scopes = ("file", "function", "basic block")
+
+        self.edit_rule_scope.addItems(scopes)
+        self.edit_rule_scope.setCurrentIndex(scopes.index(settings.user.get(CAPA_SETTINGS_RULEGEN_SCOPE, "function")))
+
+        buttons = QtWidgets.QDialogButtonBox(QtWidgets.QDialogButtonBox.Ok | QtWidgets.QDialogButtonBox.Cancel, self)
+
+        layout = QtWidgets.QFormLayout(self)
+        layout.addRow("capa rules path", self.edit_rule_path)
+        layout.addRow("Default rule author", self.edit_rule_author)
+        layout.addRow("Default rule scope", self.edit_rule_scope)
+
+        layout.addWidget(buttons)
+
+        buttons.accepted.connect(self.accept)
+        buttons.rejected.connect(self.reject)
+
+    def get_values(self):
+        """ """
+        return self.edit_rule_path.text(), self.edit_rule_author.text(), self.edit_rule_scope.currentText()
+
+
 class CapaExplorerForm(idaapi.PluginForm):
     """form element for plugin interface"""
 
@@ -197,11 +255,11 @@ class CapaExplorerForm(idaapi.PluginForm):
         self.view_rulegen = None
         self.view_tabs = None
         self.view_tab_rulegen = None
-        self.view_menu_bar = None
         self.view_status_label = None
         self.view_buttons = None
         self.view_analyze_button = None
         self.view_reset_button = None
+        self.view_settings_button = None
         self.view_save_button = None
 
         self.view_rulegen_preview = None
@@ -273,10 +331,6 @@ class CapaExplorerForm(idaapi.PluginForm):
         self.load_view_status_label()
         self.load_view_buttons()
 
-        # load menu bar and sub menus
-        self.load_view_menu_bar()
-        self.load_configure_menu()
-
         # load parent view
         self.load_view_parent()
 
@@ -285,11 +339,6 @@ class CapaExplorerForm(idaapi.PluginForm):
         tabs = QtWidgets.QTabWidget()
         self.view_tabs = tabs
 
-    def load_view_menu_bar(self):
-        """load menu bar"""
-        bar = QtWidgets.QMenuBar()
-        self.view_menu_bar = bar
-
     def load_view_checkbox_limit_by(self):
         """load limit results by function checkbox"""
         check = QtWidgets.QCheckBox("Limit results to current function")
@@ -319,19 +368,23 @@ class CapaExplorerForm(idaapi.PluginForm):
         analyze_button = QtWidgets.QPushButton("Analyze")
         reset_button = QtWidgets.QPushButton("Reset")
         save_button = QtWidgets.QPushButton("Save")
+        settings_button = QtWidgets.QPushButton("Settings")
 
         analyze_button.clicked.connect(self.slot_analyze)
         reset_button.clicked.connect(self.slot_reset)
         save_button.clicked.connect(self.slot_save)
+        settings_button.clicked.connect(self.slot_settings)
 
         layout = QtWidgets.QHBoxLayout()
         layout.addWidget(analyze_button)
         layout.addWidget(reset_button)
-        layout.addStretch(2)
+        layout.addWidget(settings_button)
+        layout.addStretch(3)
         layout.addWidget(save_button, alignment=QtCore.Qt.AlignRight)
 
         self.view_analyze_button = analyze_button
         self.view_reset_button = reset_button
+        self.view_settings_button = settings_button
         self.view_save_button = save_button
         self.view_buttons = layout
 
@@ -350,7 +403,6 @@ class CapaExplorerForm(idaapi.PluginForm):
         layout.addWidget(self.view_tabs)
         layout.addLayout(self.view_buttons)
         layout.addWidget(self.view_status_label)
-        layout.setMenuBar(self.view_menu_bar)
 
         self.parent.setLayout(layout)
 
@@ -450,27 +502,6 @@ class CapaExplorerForm(idaapi.PluginForm):
 
         self.view_tabs.addTab(tab, "Rule Generator")
 
-    def load_configure_menu(self):
-        """ """
-        actions = (
-            ("Change default rules directory...", "Set default rules directory", self.slot_change_rules_dir),
-            ("Change default rule author...", "Set default rule author", self.slot_change_rule_author),
-            ("Change default rule scope...", "Set default rule scope", self.slot_change_rule_scope),
-        )
-        self.load_menu("Settings", actions)
-
-    def load_menu(self, title, actions):
-        """load menu actions
-
-        @param title: menu name displayed in UI
-        @param actions: tuple of tuples containing action name, tooltip, and slot function
-        """
-        menu = self.view_menu_bar.addMenu(title)
-        for (name, _, slot) in actions:
-            action = QtWidgets.QAction(name, self.parent)
-            action.triggered.connect(slot)
-            menu.addAction(action)
-
     def load_ida_hooks(self):
         """load IDA UI hooks"""
         # map named action (defined in idagui.cfg) to Python function
@@ -567,7 +598,7 @@ class CapaExplorerForm(idaapi.PluginForm):
 
         try:
             # resolve rules directory - check self and settings first, then ask user
-            if not os.path.exists(settings.user.get("rule_path", "")):
+            if not os.path.exists(settings.user.get(CAPA_SETTINGS_RULE_PATH, "")):
                 idaapi.info("Please select a file directory containing capa rules.")
                 path = self.ask_user_directory()
                 if not path:
@@ -575,7 +606,7 @@ class CapaExplorerForm(idaapi.PluginForm):
                         "You must select a file directory containing capa rules before analysis can be run. The standard collection of capa rules can be downloaded from https://github.com/fireeye/capa-rules."
                     )
                     return False
-                settings.user["rule_path"] = path
+                settings.user[CAPA_SETTINGS_RULE_PATH] = path
         except Exception as e:
             logger.error("Failed to load capa rules (error: %s).", e)
             return False
@@ -584,8 +615,9 @@ class CapaExplorerForm(idaapi.PluginForm):
             logger.info("User cancelled analysis.")
             return False
 
-        rule_path = settings.user["rule_path"]
+        rule_path = settings.user[CAPA_SETTINGS_RULE_PATH]
         try:
+            # TODO refactor: this first part is identical to capa.main.get_rules
             if not os.path.exists(rule_path):
                 raise IOError("rule path %s does not exist or cannot be accessed" % rule_path)
 
@@ -601,8 +633,8 @@ class CapaExplorerForm(idaapi.PluginForm):
                         continue
                     for file in files:
                         if not file.endswith(".yml"):
-                            if not (file.endswith(".md") or file.endswith(".git") or file.endswith(".txt")):
+                            if not (file.startswith(".git") or file.endswith((".git", ".md", ".txt"))):
-                                # expect to see readme.md, format.md, and maybe a .git directory
+                                # expect to see .git* files, readme.md, format.md, and maybe a .git directory
                                 # other things maybe are rules, but are mis-named.
                                 logger.warning("skipping non-.yml file: %s", file)
                             continue
@@ -613,7 +645,8 @@ class CapaExplorerForm(idaapi.PluginForm):
             total_paths = len(rule_paths)
             for (i, rule_path) in enumerate(rule_paths):
                 update_wait_box(
-                    "loading capa rules from %s (%d of %d)" % (settings.user["rule_path"], i + 1, total_paths)
+                    "loading capa rules from %s (%d of %d)"
+                    % (settings.user[CAPA_SETTINGS_RULE_PATH], i + 1, total_paths)
                 )
                 if ida_kernwin.user_cancelled():
                     raise UserCancelledError("user cancelled")
@@ -632,12 +665,14 @@ class CapaExplorerForm(idaapi.PluginForm):
             logger.info("User cancelled analysis.")
             return False
         except Exception as e:
-            capa.ida.helpers.inform_user_ida_ui("Failed to load capa rules from %s" % settings.user["rule_path"])
+            capa.ida.helpers.inform_user_ida_ui(
-            logger.error("Failed to load rules from %s (error: %s).", settings.user["rule_path"], e)
+                "Failed to load capa rules from %s" % settings.user[CAPA_SETTINGS_RULE_PATH]
+            )
+            logger.error("Failed to load rules from %s (error: %s).", settings.user[CAPA_SETTINGS_RULE_PATH], e)
             logger.error(
                 "Make sure your file directory contains properly formatted capa rules. You can download the standard collection of capa rules from https://github.com/fireeye/capa-rules."
             )
-            settings.user["rule_path"] = ""
+            settings.user[CAPA_SETTINGS_RULE_PATH] = ""
             return False
 
         self.ruleset_cache = ruleset
@@ -743,7 +778,7 @@ class CapaExplorerForm(idaapi.PluginForm):
         try:
             self.model_data.render_capa_doc(self.doc, self.view_show_results_by_function.isChecked())
             self.set_view_status_label(
-                "capa rules directory: %s (%d rules)" % (settings.user["rule_path"], len(self.rules_cache))
+                "capa rules directory: %s (%d rules)" % (settings.user[CAPA_SETTINGS_RULE_PATH], len(self.rules_cache))
             )
         except Exception as e:
             logger.error("Failed to render results (error: %s)", e)
@@ -881,14 +916,14 @@ class CapaExplorerForm(idaapi.PluginForm):
             # load preview and feature tree
             self.view_rulegen_preview.load_preview_meta(
                 f.start_ea if f else None,
-                settings.user.get("rulegen_author", "<insert_author>"),
+                settings.user.get(CAPA_SETTINGS_RULEGEN_AUTHOR, "<insert_author>"),
-                settings.user.get("rulegen_scope", "function"),
+                settings.user.get(CAPA_SETTINGS_RULEGEN_SCOPE, "function"),
             )
             self.view_rulegen_features.load_features(file_features, func_features)
 
             # self.view_rulegen_header_label.setText("Function Features (%s)" % trim_function_name(f))
             self.set_view_status_label(
-                "capa rules directory: %s (%d rules)" % (settings.user["rule_path"], len(self.rules_cache))
+                "capa rules directory: %s (%d rules)" % (settings.user[CAPA_SETTINGS_RULE_PATH], len(self.rules_cache))
             )
         except Exception as e:
             logger.error("Failed to render views (error: %s)" % e)
@@ -985,6 +1020,12 @@ class CapaExplorerForm(idaapi.PluginForm):
 
         # create deep copy of current rules, add our new rule
         rules = copy.copy(self.rules_cache)
+
+        # ensure subscope rules are included
+        for sub in rule.extract_subscope_rules():
+            rules.append(sub)
+
+        # include our new rule in the list
         rules.append(rule)
 
         try:
@@ -1066,6 +1107,16 @@ class CapaExplorerForm(idaapi.PluginForm):
         elif self.view_tabs.currentIndex() == 1:
             self.save_function_analysis()
 
+    def slot_settings(self):
+        """ """
+        dialog = CapaSettingsInputDialog("capa explorer settings", parent=self.parent)
+        if dialog.exec_():
+            (
+                settings.user[CAPA_SETTINGS_RULE_PATH],
+                settings.user[CAPA_SETTINGS_RULEGEN_AUTHOR],
+                settings.user[CAPA_SETTINGS_RULEGEN_SCOPE],
+            ) = dialog.get_values()
+
     def save_program_analysis(self):
         """ """
         if not self.doc:
@@ -1143,42 +1194,16 @@ class CapaExplorerForm(idaapi.PluginForm):
         """create Qt dialog to ask user for a directory"""
         return str(
             QtWidgets.QFileDialog.getExistingDirectory(
-                self.parent, "Please select a capa rules directory", settings.user["rule_path"]
+                self.parent, "Please select a capa rules directory", settings.user.get(CAPA_SETTINGS_RULE_PATH, "")
             )
         )
 
     def ask_user_capa_rule_file(self):
         """ """
         return QtWidgets.QFileDialog.getSaveFileName(
-            None, "Please select a capa rule to edit", settings.user["rule_path"], "*.yml"
+            None, "Please select a capa rule to edit", settings.user.get(CAPA_SETTINGS_RULE_PATH, ""), "*.yml"
         )[0]
 
-    def slot_change_rule_scope(self):
-        """ """
-        scope = idaapi.ask_str(str(settings.user.get("rulegen_scope", "function")), 0, "Enter default rule scope")
-        if scope:
-            settings.user["rulegen_scope"] = scope
-            idaapi.info("Run analysis again for your changes to take effect.")
-
-    def slot_change_rule_author(self):
-        """ """
-        author = idaapi.ask_str(str(settings.user.get("rulegen_author", "")), 0, "Enter default rule author")
-        if author:
-            settings.user["rulegen_author"] = author
-            idaapi.info("Run analysis again for your changes to take effect.")
-
-    def slot_change_rules_dir(self):
-        """allow user to change rules directory
-
-        user selection stored in settings for future runs
-        """
-        path = self.ask_user_directory()
-        if path:
-            settings.user["rule_path"] = path
-            self.rules_cache = None
-            self.ruleset_cache = None
-            idaapi.info("Run analysis again for your changes to take effect.")
-
     def set_view_status_label(self, text):
         """update status label control
 

capa/ida/plugin/item.py

@@ -202,7 +202,7 @@ class CapaExplorerRuleMatchItem(CapaExplorerDataItem):
 
     @property
     def source(self):
-        """ return rule contents for display """
+        """return rule contents for display"""
         return self._source
 
 
@@ -328,14 +328,10 @@ class CapaExplorerByteViewItem(CapaExplorerFeatureItem):
         """
         byte_snap = idaapi.get_bytes(location, 32)
 
+        details = ""
         if byte_snap:
             byte_snap = codecs.encode(byte_snap, "hex").upper()
-            if sys.version_info >= (3, 0):
+            details = " ".join([byte_snap[i : i + 2].decode() for i in range(0, len(byte_snap), 2)])
-                details = " ".join([byte_snap[i : i + 2].decode() for i in range(0, len(byte_snap), 2)])
-            else:
-                details = " ".join([byte_snap[i : i + 2] for i in range(0, len(byte_snap), 2)])
-        else:
-            details = ""
 
         super(CapaExplorerByteViewItem, self).__init__(parent, display, location=location, details=details)
         self.ida_highlight = idc.get_color(location, idc.CIC_ITEM)

capa/ida/plugin/model.py

@@ -488,13 +488,17 @@ class CapaExplorerDataModel(QtCore.QAbstractItemModel):
 
         @param feature: capa feature read from doc
         """
-        if feature[feature["type"]]:
+        key = feature["type"]
+        value = feature[feature["type"]]
+        if value:
+            if key == "string":
+                value = '"%s"' % capa.features.escape_string(value)
             if feature.get("description", ""):
-                return "%s(%s = %s)" % (feature["type"], feature[feature["type"]], feature["description"])
+                return "%s(%s = %s)" % (key, value, feature["description"])
             else:
-                return "%s(%s)" % (feature["type"], feature[feature["type"]])
+                return "%s(%s)" % (key, value)
         else:
-            return "%s" % feature["type"]
+            return "%s" % key
 
     def render_capa_doc_feature_node(self, parent, feature, locations, doc):
         """process capa doc feature node
@@ -551,7 +555,9 @@ class CapaExplorerDataModel(QtCore.QAbstractItemModel):
             )
 
         if feature["type"] == "regex":
-            return CapaExplorerStringViewItem(parent, display, location, feature["match"])
+            return CapaExplorerStringViewItem(
+                parent, display, location, '"%s"' % capa.features.escape_string(feature["match"])
+            )
 
         if feature["type"] == "basicblock":
             return CapaExplorerBlockItem(parent, location)
@@ -576,7 +582,9 @@ class CapaExplorerDataModel(QtCore.QAbstractItemModel):
 
         if feature["type"] in ("string",):
             # display string preview
-            return CapaExplorerStringViewItem(parent, display, location, feature[feature["type"]])
+            return CapaExplorerStringViewItem(
+                parent, display, location, '"%s"' % capa.features.escape_string(feature[feature["type"]])
+            )
 
         if feature["type"] in ("import", "export"):
             # display no preview

capa/ida/plugin/proxy.py

@@ -5,7 +5,6 @@
 # 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 six
 from PyQt5 import QtCore
 from PyQt5.QtCore import Qt
 
@@ -208,7 +207,7 @@ class CapaExplorerSearchProxyModel(QtCore.QSortFilterProxyModel):
             if not data:
                 continue
 
-            if not isinstance(data, six.string_types):
+            if not isinstance(data, str):
                 # sanity check: should already be a string, but double check
                 continue
 

capa/ida/plugin/view.py

@@ -178,6 +178,9 @@ def build_context_menu(o, actions):
 
 
 class CapaExplorerRulgenPreview(QtWidgets.QTextEdit):
+
+    INDENT = " " * 2
+
     def __init__(self, parent=None):
         """ """
         super(CapaExplorerRulgenPreview, self).__init__(parent)
@@ -210,12 +213,99 @@ class CapaExplorerRulgenPreview(QtWidgets.QTextEdit):
         self.setText("\n".join(metadata_default))
 
     def keyPressEvent(self, e):
-        """ """
+        """intercept key press events"""
-        if e.key() == QtCore.Qt.Key_Tab:
+        if e.key() in (QtCore.Qt.Key_Tab, QtCore.Qt.Key_Backtab):
-            self.insertPlainText(" " * 2)
+            # apparently it's not easy to implement tabs as spaces, or multi-line tab or SHIFT + Tab
+            # so we need to implement it ourselves so we can retain properly formatted capa rules
+            # when a user uses the Tab key
+            if self.textCursor().selection().isEmpty():
+                # single line, only worry about Tab
+                if e.key() == QtCore.Qt.Key_Tab:
+                    self.insertPlainText(self.INDENT)
+            else:
+                # multi-line tab or SHIFT + Tab
+                cur = self.textCursor()
+                select_start_ppos = cur.selectionStart()
+                select_end_ppos = cur.selectionEnd()
+
+                scroll_ppos = self.verticalScrollBar().sliderPosition()
+
+                # determine lineno for first selected line, and column
+                cur.setPosition(select_start_ppos)
+                start_lineno = self.count_previous_lines_from_block(cur.block())
+                start_lineco = cur.columnNumber()
+
+                # determine lineno for last selected line
+                cur.setPosition(select_end_ppos)
+                end_lineno = self.count_previous_lines_from_block(cur.block())
+
+                # now we need to indent or dedent the selected lines. for now, we read the text, modify
+                # the lines between start_lineno and end_lineno accordingly, and then reset the view
+                # this might not be the best solution, but it avoids messing around with cursor positions
+                # to determine the beginning of lines
+
+                plain = self.toPlainText().splitlines()
+
+                if e.key() == QtCore.Qt.Key_Tab:
+                    # user Tab, indent selected lines
+                    lines_modified = end_lineno - start_lineno
+                    first_modified = True
+                    change = [self.INDENT + line for line in plain[start_lineno : end_lineno + 1]]
+                else:
+                    # user SHIFT + Tab, dedent selected lines
+                    lines_modified = 0
+                    first_modified = False
+                    change = []
+                    for (lineno, line) in enumerate(plain[start_lineno : end_lineno + 1]):
+                        if line.startswith(self.INDENT):
+                            if lineno == 0:
+                                # keep track if first line is modified, so we can properly display
+                                # the text selection later
+                                first_modified = True
+                            lines_modified += 1
+                            line = line[len(self.INDENT) :]
+                        change.append(line)
+
+                # apply modifications, and reset view
+                plain[start_lineno : end_lineno + 1] = change
+                self.setPlainText("\n".join(plain) + "\n")
+
+                # now we need to properly adjust the selection positions, so users don't have to
+                # re-select when indenting or dedenting the same lines repeatedly
+                if e.key() == QtCore.Qt.Key_Tab:
+                    # user Tab, increase increment selection positions
+                    select_start_ppos += len(self.INDENT)
+                    select_end_ppos += (lines_modified * len(self.INDENT)) + len(self.INDENT)
+                elif lines_modified:
+                    # user SHIFT + Tab, decrease selection positions
+                    if start_lineco not in (0, 1) and first_modified:
+                        # only decrease start position if not in first column
+                        select_start_ppos -= len(self.INDENT)
+                    select_end_ppos -= lines_modified * len(self.INDENT)
+
+                # apply updated selection and restore previous scroll position
+                self.set_selection(select_start_ppos, select_end_ppos, len(self.toPlainText()))
+                self.verticalScrollBar().setSliderPosition(scroll_ppos)
         else:
             super(CapaExplorerRulgenPreview, self).keyPressEvent(e)
 
+    def count_previous_lines_from_block(self, block):
+        """calculate number of lines preceding block"""
+        count = 0
+        while True:
+            block = block.previous()
+            if not block.isValid():
+                break
+            count += block.lineCount()
+        return count
+
+    def set_selection(self, start, end, max):
+        """set text selection"""
+        cursor = self.textCursor()
+        cursor.setPosition(start)
+        cursor.setPosition(end if end < max else max, QtGui.QTextCursor.KeepAnchor)
+        self.setTextCursor(cursor)
+
 
 class CapaExplorerRulgenEditor(QtWidgets.QTreeWidget):
 
@@ -325,6 +415,11 @@ class CapaExplorerRulgenEditor(QtWidgets.QTreeWidget):
         # create a new parent under root node, by default; new node added last position in tree
         new_parent = self.new_expression_node(self.root, (action.data()[0], ""))
 
+        if "basic block" in action.data()[0]:
+            # add default child expression when nesting under basic block
+            new_parent.setExpanded(True)
+            new_parent = self.new_expression_node(new_parent, ("- or:", ""))
+
         for o in self.get_features(selected=True):
             # take child from its parent by index, add to new parent
             new_parent.addChild(o.parent().takeChild(o.parent().indexOfChild(o)))
@@ -335,6 +430,15 @@ class CapaExplorerRulgenEditor(QtWidgets.QTreeWidget):
     def slot_edit_expression(self, action):
         """ """
         expression, o = action.data()
+        if "basic block" in expression and "basic block" not in o.text(
+            CapaExplorerRulgenEditor.get_column_feature_index()
+        ):
+            # current expression is "basic block", and not changing to "basic block" expression
+            children = o.takeChildren()
+            new_parent = self.new_expression_node(o, ("- or:", ""))
+            for child in children:
+                new_parent.addChild(child)
+            new_parent.setExpanded(True)
         o.setText(CapaExplorerRulgenEditor.get_column_feature_index(), expression)
 
     def slot_clear_all(self, action):
@@ -520,11 +624,23 @@ class CapaExplorerRulgenEditor(QtWidgets.QTreeWidget):
 
         # single features
         for (k, v) in filter(lambda t: t[1] == 1, counted):
-            self.new_feature_node(self.root, ("- %s: %s" % (k.name.lower(), k.get_value_str()), ""))
+            if isinstance(k, (capa.features.String,)):
+                value = '"%s"' % capa.features.escape_string(k.get_value_str())
+            else:
+                value = k.get_value_str()
+            self.new_feature_node(self.root, ("- %s: %s" % (k.name.lower(), value), ""))
 
         # n > 1 features
         for (k, v) in filter(lambda t: t[1] > 1, counted):
-            self.new_feature_node(self.root, ("- count(%s): %d" % (str(k), v), ""))
+            if k.value:
+                if isinstance(k, (capa.features.String,)):
+                    value = '"%s"' % capa.features.escape_string(k.get_value_str())
+                else:
+                    value = k.get_value_str()
+                display = "- count(%s(%s)): %d" % (k.name.lower(), value, v)
+            else:
+                display = "- count(%s): %d" % (k.name.lower(), v)
+            self.new_feature_node(self.root, (display, ""))
 
         self.expandAll()
         self.update_preview()
@@ -699,9 +815,11 @@ class CapaExplorerRulegenFeatures(QtWidgets.QTreeWidget):
         if text:
             for o in iterate_tree(self):
                 data = o.data(0, 0x100)
-                if data and text.lower() not in data.get_value_str().lower():
+                if data:
-                    o.setHidden(True)
+                    to_match = data.get_value_str()
-                    continue
+                    if not to_match or text.lower() not in to_match.lower():
+                        o.setHidden(True)
+                        continue
                 o.setHidden(False)
                 o.setExpanded(True)
         else:
@@ -776,16 +894,20 @@ class CapaExplorerRulegenFeatures(QtWidgets.QTreeWidget):
         def format_address(e):
             return "%X" % e if e else ""
 
+        def format_feature(feature):
+            """ """
+            name = feature.name.lower()
+            value = feature.get_value_str()
+            if isinstance(feature, (capa.features.String,)):
+                value = '"%s"' % capa.features.escape_string(value)
+            return "%s(%s)" % (name, value)
+
         for (feature, eas) in sorted(features.items(), key=lambda k: sorted(k[1])):
             if isinstance(feature, capa.features.basicblock.BasicBlock):
                 # filter basic blocks for now, we may want to add these back in some time
                 # in the future
                 continue
 
-            if isinstance(feature, capa.features.String):
-                # strip string for display
-                feature.value = feature.value.strip()
-
             # level 0
             if type(feature) not in self.parent_items:
                 self.parent_items[type(feature)] = self.new_parent_node(parent, (feature.name.lower(),))
@@ -794,20 +916,22 @@ class CapaExplorerRulegenFeatures(QtWidgets.QTreeWidget):
             if feature not in self.parent_items:
                 if len(eas) > 1:
                     self.parent_items[feature] = self.new_parent_node(
-                        self.parent_items[type(feature)], (str(feature),), feature=feature
+                        self.parent_items[type(feature)], (format_feature(feature),), feature=feature
                     )
                 else:
                     self.parent_items[feature] = self.new_leaf_node(
-                        self.parent_items[type(feature)], (str(feature),), feature=feature
+                        self.parent_items[type(feature)], (format_feature(feature),), feature=feature
                     )
 
             # level n > 1
             if len(eas) > 1:
                 for ea in sorted(eas):
-                    self.new_leaf_node(self.parent_items[feature], (str(feature), format_address(ea)), feature=feature)
+                    self.new_leaf_node(
+                        self.parent_items[feature], (format_feature(feature), format_address(ea)), feature=feature
+                    )
             else:
                 ea = eas.pop()
-                for (i, v) in enumerate((str(feature), format_address(ea))):
+                for (i, v) in enumerate((format_feature(feature), format_address(ea))):
                     self.parent_items[feature].setText(i, v)
                 self.parent_items[feature].setData(0, 0x100, feature)
 

capa/main.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 """
 Copyright (C) 2020 FireEye, Inc. All Rights Reserved.
 Licensed under the Apache License, Version 2.0 (the "License");
@@ -38,6 +38,8 @@ RULES_PATH_DEFAULT_STRING = "(embedded rules)"
 SUPPORTED_FILE_MAGIC = set([b"MZ"])
 BACKEND_VIV = "vivisect"
 BACKEND_SMDA = "smda"
+EXTENSIONS_SHELLCODE_32 = ("sc32", "raw32")
+EXTENSIONS_SHELLCODE_64 = ("sc64", "raw64")
 
 
 logger = logging.getLogger("capa")
@@ -389,26 +391,15 @@ def get_workspace(path, format, sigpaths):
     return vw
 
 
-def get_extractor_py2(path, format, sigpaths, disable_progress=False):
-    import capa.features.extractors.viv
-
-    with halo.Halo(text="analyzing program", spinner="simpleDots", stream=sys.stderr, enabled=not disable_progress):
-        vw = get_workspace(path, format, sigpaths)
-
-        try:
-            vw.saveWorkspace()
-        except IOError:
-            # see #168 for discussion around how to handle non-writable directories
-            logger.info("source directory is not writable, won't save intermediate workspace")
-
-    return capa.features.extractors.viv.VivisectFeatureExtractor(vw, path)
-
-
 class UnsupportedRuntimeError(RuntimeError):
     pass
 
 
-def get_extractor_py3(path, format, backend, sigpaths, disable_progress=False):
+def get_extractor(path, format, backend, sigpaths, disable_progress=False):
+    """
+    raises:
+      UnsupportedFormatError:
+    """
     if backend == "smda":
         from smda.SmdaConfig import SmdaConfig
         from smda.Disassembler import Disassembler
@@ -427,7 +418,11 @@ def get_extractor_py3(path, format, backend, sigpaths, disable_progress=False):
         import capa.features.extractors.viv
 
         with halo.Halo(text="analyzing program", spinner="simpleDots", stream=sys.stderr, enabled=not disable_progress):
-            vw = get_workspace(path, format, sigpaths)
+            if format == "auto" and path.endswith(EXTENSIONS_SHELLCODE_32):
+                format = "sc32"
+            elif format == "auto" and path.endswith(EXTENSIONS_SHELLCODE_64):
+                format = "sc64"
+            vw = get_workspace(path, format, sigpaths, should_save=False)
 
             try:
                 vw.saveWorkspace()
@@ -438,22 +433,6 @@ def get_extractor_py3(path, format, backend, sigpaths, disable_progress=False):
         return capa.features.extractors.viv.VivisectFeatureExtractor(vw, path)
 
 
-def get_extractor(path, format, backend, sigpaths, disable_progress=False):
-    """
-    args:
-      path (str): file system path to file to analyze.
-      format (str): "auto" for autodetection or one of "pe", "sc32" or "sc64" to override.
-      sigpaths (List[str]): file system paths to .sig/.pat files to identify functions.
-
-    raises:
-      UnsupportedFormatError:
-    """
-    if sys.version_info >= (3, 0):
-        return get_extractor_py3(path, format, backend, sigpaths, disable_progress=disable_progress)
-    else:
-        return get_extractor_py2(path, format, sigpaths, disable_progress=disable_progress)
-
-
 def is_nursery_rule_path(path):
     """
     The nursery is a spot for rules that have not yet been fully polished.
@@ -485,8 +464,8 @@ def get_rules(rule_path, disable_progress=False):
 
             for file in files:
                 if not file.endswith(".yml"):
-                    if not (file.endswith(".md") or file.endswith(".git") or file.endswith(".txt")):
+                    if not (file.startswith(".git") or file.endswith((".git", ".md", ".txt"))):
-                        # expect to see readme.md, format.md, and maybe a .git directory
+                        # expect to see .git* files, readme.md, format.md, and maybe a .git directory
                         # other things maybe are rules, but are mis-named.
                         logger.warning("skipping non-.yml file: %s", file)
                     continue
@@ -566,7 +545,7 @@ def install_common_args(parser, wanted=None):
       wanted (Set[str]): collection of arguments to opt-into, including:
         - "sample": required positional argument to input file.
         - "format": flag to override file format.
-        - "backend": flag to override analysis backend under py3.
+        - "backend": flag to override analysis backend.
         - "rules": flag to override path to capa rules.
         - "tag": flag to override/specify which rules to match.
     """
@@ -604,22 +583,11 @@ def install_common_args(parser, wanted=None):
     #
 
     if "sample" in wanted:
-        if sys.version_info >= (3, 0):
+        parser.add_argument(
-            parser.add_argument(
+            "sample",
-                # Python 3 str handles non-ASCII arguments correctly
+            type=str,
-                "sample",
+            help="path to sample to analyze",
-                type=str,
+        )
-                help="path to sample to analyze",
-            )
-        else:
-            parser.add_argument(
-                # in #328 we noticed that the sample path is not handled correctly if it contains non-ASCII characters
-                # https://stackoverflow.com/a/22947334/ offers a solution and decoding using getfilesystemencoding works
-                # in our testing, however other sources suggest `sys.stdin.encoding` (https://stackoverflow.com/q/4012571/)
-                "sample",
-                type=lambda s: s.decode(sys.getfilesystemencoding()),
-                help="path to sample to analyze",
-            )
 
     if "format" in wanted:
         formats = [
@@ -638,15 +606,15 @@ def install_common_args(parser, wanted=None):
             help="select sample format, %s" % format_help,
         )
 
-    if "backend" in wanted and sys.version_info >= (3, 0):
+        if "backend" in wanted:
-        parser.add_argument(
+            parser.add_argument(
-            "-b",
+                "-b",
-            "--backend",
+                "--backend",
-            type=str,
+                type=str,
-            help="select the backend to use",
+                help="select the backend to use",
-            choices=(BACKEND_VIV, BACKEND_SMDA),
+                choices=(BACKEND_VIV, BACKEND_SMDA),
-            default=BACKEND_VIV,
+                default=BACKEND_VIV,
-        )
+            )
 
     if "rules" in wanted:
         parser.add_argument(
@@ -694,10 +662,9 @@ def handle_common_args(args):
     # disable vivisect-related logging, it's verbose and not relevant for capa users
     set_vivisect_log_level(logging.CRITICAL)
 
-    # py2 doesn't know about cp65001, which is a variant of utf-8 on windows
+    # Since Python 3.8 cp65001 is an alias to utf_8, but not for Pyhton < 3.8
-    # tqdm bails when trying to render the progress bar in this setup.
+    # TODO: remove this code when only supporting Python 3.8+
-    # because cp65001 is utf-8, we just map that codepage to the utf-8 codec.
+    # https://stackoverflow.com/a/3259271/87207
-    # see #380 and: https://stackoverflow.com/a/3259271/87207
     import codecs
 
     codecs.register(lambda name: codecs.lookup("utf-8") if name == "cp65001" else None)
@@ -717,6 +684,9 @@ def handle_common_args(args):
 
 
 def main(argv=None):
+    if sys.version_info < (3, 6):
+        raise UnsupportedRuntimeError("This version of capa can only be used with Python 3.6+")
+
     if argv is None:
         argv = sys.argv[1:]
 
@@ -821,8 +791,7 @@ def main(argv=None):
     else:
         format = args.format
         try:
-            backend = args.backend if sys.version_info > (3, 0) else BACKEND_VIV
+            extractor = get_extractor(args.sample, format, args.backend, args.signatures, disable_progress=args.quiet)
-            extractor = get_extractor(args.sample, args.format, backend, args.signatures, disable_progress=args.quiet)
         except UnsupportedFormatError:
             logger.error("-" * 80)
             logger.error(" Input file does not appear to be a PE file.")
@@ -833,16 +802,6 @@ def main(argv=None):
             logger.error(" If you don't know the input file type, you can try using the `file` utility to guess it.")
             logger.error("-" * 80)
             return -1
-        except UnsupportedRuntimeError:
-            logger.error("-" * 80)
-            logger.error(" Unsupported runtime or Python interpreter.")
-            logger.error(" ")
-            logger.error(" capa supports running under Python 2.7 using Vivisect for binary analysis.")
-            logger.error(" It can also run within IDA Pro, using either Python 2.7 or 3.5+.")
-            logger.error(" ")
-            logger.error(" If you're seeing this message on the command line, please ensure you're running Python 2.7.")
-            logger.error("-" * 80)
-            return -1
 
     meta = collect_metadata(argv, args.sample, args.rules, format, extractor)
 

capa/render/__init__.py

@@ -8,8 +8,6 @@
 
 import json
 
-import six
-
 import capa.rules
 import capa.engine
 
@@ -249,7 +247,7 @@ class CapaJsonObjectEncoder(json.JSONEncoder):
     """JSON encoder that emits Python sets as sorted lists"""
 
     def default(self, obj):
-        if isinstance(obj, (list, dict, int, float, bool, type(None))) or isinstance(obj, six.string_types):
+        if isinstance(obj, (list, dict, int, float, bool, type(None))) or isinstance(obj, str):
             return json.JSONEncoder.default(self, obj)
         elif isinstance(obj, set):
             return list(sorted(obj))

capa/render/default.py

@@ -8,7 +8,6 @@
 
 import collections
 
-import six
 import tabulate
 
 import capa.render.utils as rutils

capa/render/utils.py

@@ -6,7 +6,8 @@
 #  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 six
+import io
+
 import termcolor
 
 
@@ -49,7 +50,7 @@ def capability_rules(doc):
         yield rule
 
 
-class StringIO(six.StringIO):
+class StringIO(io.StringIO):
     def writeln(self, s):
         self.write(s)
         self.write("\n")

capa/render/vverbose.py

@@ -56,7 +56,11 @@ def render_statement(ostream, match, statement, indent=0):
         child = statement["child"]
 
         if child[child["type"]]:
-            value = rutils.bold2(child[child["type"]])
+            if child["type"] == "string":
+                value = '"%s"' % capa.features.escape_string(child[child["type"]])
+            else:
+                value = child[child["type"]]
+            value = rutils.bold2(value)
             if child.get("description"):
                 ostream.write("count(%s(%s = %s)): " % (child["type"], value, child["description"]))
             else:
@@ -90,6 +94,9 @@ def render_feature(ostream, match, feature, indent=0):
         key = "string"  # render string for regex to mirror the rule source
         value = feature["match"]  # the match provides more information than the value for regex
 
+    if key == "string":
+        value = '"%s"' % capa.features.escape_string(value)
+
     ostream.write(key)
     ostream.write(": ")
 

capa/rules.py

@@ -18,7 +18,8 @@ try:
 except ImportError:
     from backports.functools_lru_cache import lru_cache
 
-import six
+import io
+
 import yaml
 import ruamel.yaml
 
@@ -244,7 +245,7 @@ def parse_description(s, value_type, description=None):
     """
     s can be an int or a string
     """
-    if value_type != "string" and isinstance(s, six.string_types) and DESCRIPTION_SEPARATOR in s:
+    if value_type != "string" and isinstance(s, str) and DESCRIPTION_SEPARATOR in s:
         if description:
             raise InvalidRule(
                 'unexpected value: "%s", only one description allowed (inline description with `%s`)'
@@ -256,12 +257,11 @@ def parse_description(s, value_type, description=None):
     else:
         value = s
 
-    if isinstance(value, six.string_types):
+    if isinstance(value, str):
         if value_type == "bytes":
             try:
                 value = codecs.decode(value.replace(" ", ""), "hex")
-            # TODO: Remove TypeError when Python2 is not used anymore
+            except binascii.Error:
-            except (TypeError, binascii.Error):
                 raise InvalidRule('unexpected bytes value: "%s", must be a valid hex sequence' % value)
 
             if len(value) > MAX_BYTES_FEATURE_SIZE:
@@ -406,7 +406,7 @@ def build_statements(d, scope):
             return Range(feature, min=min, max=max, description=description)
         else:
             raise InvalidRule("unexpected range: %s" % (count))
-    elif key == "string" and not isinstance(d[key], six.string_types):
+    elif key == "string" and not isinstance(d[key], str):
         raise InvalidRule("ambiguous string value %s, must be defined as explicit string" % d[key])
     else:
         Feature = parse_feature(key)
@@ -699,7 +699,7 @@ class Rule(object):
         for key in hidden_meta.keys():
             del meta[key]
 
-        ostream = six.BytesIO()
+        ostream = io.BytesIO()
         self._get_ruamel_yaml_parser().dump(definition, ostream)
 
         for key, value in hidden_meta.items():
@@ -736,6 +736,8 @@ class Rule(object):
         # the below regex makes these adjustments and while ugly, we don't have to explore the ruamel.yaml insides
         doc = re.sub(r"!!int '0x-([0-9a-fA-F]+)'", r"-0x\1", doc)
 
+        # normalize CRLF to LF
+        doc = doc.replace("\r\n", "\n")
         return doc
 
 
@@ -936,7 +938,7 @@ class RuleSet(object):
         rules_filtered = set([])
         for rule in rules:
             for k, v in rule.meta.items():
-                if isinstance(v, six.string_types) and tag in v:
+                if isinstance(v, str) and tag in v:
                     logger.debug('using rule "%s" and dependencies, found tag in meta.%s: %s', rule.name, k, v)
                     rules_filtered.update(set(capa.rules.get_rules_and_dependencies(rules, rule.name)))
                     break

capa/version.py

@@ -1 +1 @@
-__version__ = "1.5.1"
+__version__ = "1.6.1"

doc/installation.md

@@ -42,6 +42,7 @@ If you'd like to review and modify the capa source code, you'll need to check it
 Next, clone the capa git repository.
 We use submodules to separate [code](https://github.com/fireeye/capa), [rules](https://github.com/fireeye/capa-rules), and [test data](https://github.com/fireeye/capa-testfiles).
 To clone everything use the `--recurse-submodules` option:
+- CAUTION: The capa testfiles repository contains many malware samples. If you pull down everything using this method, you may want to install to a directory that won't trigger your anti-virus software.
 - `$ git clone --recurse-submodules https://github.com/fireeye/capa.git /local/path/to/src` (HTTPS)
 - `$ git clone --recurse-submodules git@github.com:fireeye/capa.git /local/path/to/src` (SSH)
 
@@ -59,6 +60,25 @@ Use `pip` to install the source code in "editable" mode. This means that Python
 
 You'll find that the `capa.exe` (Windows) or `capa` (Linux/MacOS) executables in your path now invoke the capa binary from this directory.
 
+#### Development
+
+##### venv [optional]
+
+For development, we recommend to use [venv](https://docs.python.org/3/tutorial/venv.html). It allows you to create a virtual environment: a self-contained directory tree that contains a Python installation for a particular version of Python, plus a number of additional packages. This approach avoids conflicts between the requirements of different applications on your computer. It also ensures that you don't overlook to add a new requirement to `setup.up` using a library already installed on your system.
+
+To create an environment (in the parent directory, to avoid commiting it by accident or messing with the linters), run:
+`$ python3 -m venv ../capa-env`
+
+To activate `capa-env` in Linux or MacOS, run:
+`$ source ../capa-env/bin/activate`
+
+To activate `capa-env` in Windows, run:
+`$ ..\capa-env\Scripts\activate.bat`
+
+For more details about creating and using virtual environments, check out the [venv documentation](https://docs.python.org/3/tutorial/venv.html).
+
+##### Install development dependencies
+
 We use the following tools to ensure consistent code style and formatting:
   - [black](https://github.com/psf/black) code formatter, with `-l 120`
   - [isort 5](https://pypi.org/project/isort/) code formatter, with `--profile black --length-sort --line-width 120`
@@ -69,30 +89,28 @@ To install these development dependencies, run:
 
 `$ pip install -e /local/path/to/src[dev]`
 
-Note that some development dependencies (including the black code formatter) require Python 3.
-
 To check the code style, formatting and run the tests you can run the script `scripts/ci.sh`.
 You can run it with the argument `no_tests` to skip the tests and only run the code style and formatting: `scripts/ci.sh no_tests`
 
+##### Setup hooks [optional]
+
+If you plan to contribute to capa, you may want to setup the hooks.
+Run `scripts/setup-hooks.sh` to set the following hooks up:
+- The `pre-commit` hook runs checks before every `git commit`.
+  It runs `scripts/ci.sh no_tests` aborting the commit if there are code style or rule linter offenses you need to fix.
+- The `pre-push` hook runs checks before every `git push`.
+  It runs `scripts/ci.sh` aborting the push if there are code style or rule linter offenses or if the tests fail.
+  This way you can ensure everything is alright before sending a pull request.
+
+You can skip the checks by using the `--no-verify` git option.
+
 ### 3. Compile binary using PyInstaller
 We compile capa standalone binaries using PyInstaller. To reproduce the build process check out the source code as described above and follow these steps.
 
 #### Install PyInstaller:
-For Python 2.7: `$ pip install 'pyinstaller==3.*'` (PyInstaller 4 doesn't support Python 2.7)
+`$ pip install pyinstaller` (Python 3)
-
-For Python 3: `$ pip install 'pyinstaller`
 
 #### Run Pyinstaller
 `$ pyinstaller .github/pyinstaller/pyinstaller.spec`
 
 You can find the compiled binary in the created directory `dist/`.
-
-### 4. Setup hooks [optional]
-If you plan to contribute to capa, you may want to setup the hooks.
-Run `scripts/setup-hooks.sh` to set the following hooks up:
-- The `pre-commit` hook runs checks before every `git commit`.
-  It runs `scripts/ci.sh no_tests` aborting the commit if there are code style or rule linter offenses you need to fix.
-  You can skip this check by using the `--no-verify` git option.
-- The `pre-push` hook runs checks before every `git push`.
-  It runs `scripts/ci.sh` aborting the push if there are code style or rule linter offenses or if the tests fail.
-  This way you can ensure everything is alright before sending a pull request.

doc/release.md

@@ -0,0 +1,44 @@
+# Release checklist
+
+- [ ] Ensure all [milestoned issues/PRs](https://github.com/fireeye/capa/milestones) are addressed, or reassign to a new milestone.
+- [ ] Add the `dont merge` label to all PRs that are close to be ready to merge (or merge them if they are ready) in [capa](https://github.com/fireeye/capa/pulls) and [capa-rules](https://github.com/fireeye/capa-rules/pulls).
+- [ ] Ensure the [CI workflow succeeds in master](https://github.com/fireeye/capa/actions/workflows/tests.yml?query=branch%3Amaster).
+- [ ] Ensure that `python scripts/lint.py rules/ --thorough` succeeds (only `missing examples`  offenses are allowed in the nursery).
+- [ ] Review changes
+  - capa https://github.com/fireeye/capa/compare/\<last-release\>...master
+  - capa-rules https://github.com/fireeye/capa-rules/compare/\<last-release>\...master
+- [ ] Update [CHANGELOG.md](https://github.com/fireeye/capa/blob/master/CHANGELOG.md)
+  - Do not forget to add a nice introduction thanking contributors
+  - Remember that we need a major release if we introduce breaking changes
+  - Sections
+    - New Features
+    - New Rules
+    - Bug Fixes
+    - Changes
+    - Development
+    - Raw diffs
+  - Update `Raw diffs` links
+  - Create placeholder for `master (unreleased)` section
+    ```
+    ## master (unreleased)
+
+    ### New Features
+
+    ### New Rules
+
+    ### Bug Fixes
+
+    ### Changes
+
+    ### Development
+
+    ### Raw diffs
+    - [capa <release>...master](https://github.com/fireeye/capa/compare/<release>...master)
+    - [capa-rules <release>...master](https://github.com/fireeye/capa-rules/compare/<release>...master)
+    ```
+- [ ] Update [capa/version.py](https://github.com/fireeye/capa/blob/master/capa/version.py)
+- [ ] Create a PR with the updated [CHANGELOG.md](https://github.com/fireeye/capa/blob/master/CHANGELOG.md) and [capa/version.py](https://github.com/fireeye/capa/blob/master/capa/version.py). Copy this checklist in the PR description.
+- [ ] After PR review, merge the PR and [create the release in GH](https://github.com/fireeye/capa/releases/new) using text from the [CHANGELOG.md](https://github.com/fireeye/capa/blob/master/CHANGELOG.md).
+- [ ] Verify GH actions [upload artifacts](https://github.com/fireeye/capa/releases), [publish to PyPI](https://pypi.org/project/flare-capa) and [create a tag in capa rules](https://github.com/fireeye/capa-rules/tags) upon completion.
+- [ ] [Spread the word](https://twitter.com)
+

scripts/capafmt.py

@@ -65,6 +65,8 @@ def main(argv=None):
             return 0
         else:
             logger.info("rule requires reformatting (%s)", rule.name)
+            if "\r\n" in rule.definition:
+                logger.info("please make sure that the file uses LF (\\n) line endings only")
             return 1
 
     if args.in_place:

scripts/ci.sh

@@ -9,6 +9,7 @@
 # See the License for the specific language governing permissions and limitations under the License.
 
 # Use a console with emojis support for a better experience
+# Use venv to ensure that `python` calls the correct python version
 
 # Stash uncommited changes
 MSG="pre-push-$(date +%s)";
@@ -25,17 +26,8 @@ restore_stashed() {
   fi
 }
 
-python_3() {
-  case "$(uname -s)" in
-   CYGWIN*|MINGW32*|MSYS*|MINGW*)
-     py -3 -m $1 > $2 2>&1;;
-   *)
-     python3 -m $1 > $2 2>&1;;
-  esac
-}
-
 # Run isort and print state
-python_3 'isort --profile black --length-sort --line-width 120 -c .' 'isort-output.log';
+python -m isort --profile black --length-sort --line-width 120 -c . > isort-output.log 2>&1;
 if [ $? == 0 ]; then
   echo 'isort succeeded!! 💖';
 else
@@ -46,7 +38,7 @@ else
 fi
 
 # Run black and print state
-python_3 'black -l 120 --check .' 'black-output.log';
+python -m black -l 120 --check . > black-output.log 2>&1;
 if [ $? == 0 ]; then
   echo 'black succeeded!! 💝';
 else
@@ -70,7 +62,7 @@ fi
 # Run tests except if first argument is no_tests
 if [ "$1" != 'no_tests' ]; then
   echo 'Running tests, please wait ⌛';
-  pytest tests/ --maxfail=1;
+  python -m pytest tests/ --maxfail=1;
   if [ $? == 0 ]; then
     echo 'Tests succeed!! 🎉';
   else

scripts/lint.py

@@ -25,13 +25,15 @@ import argparse
 import itertools
 import posixpath
 
+import ruamel.yaml
+
 import capa.main
 import capa.rules
 import capa.engine
 import capa.features
 import capa.features.insn
 
-logger = logging.getLogger("capa.lint")
+logger = logging.getLogger("lint")
 
 
 class Lint(object):
@@ -303,6 +305,16 @@ class FeatureNtdllNtoskrnlApi(Lint):
         return False
 
 
+class FormatLineFeedEOL(Lint):
+    name = "line(s) end with CRLF (\\r\\n)"
+    recommendation = "convert line endings to LF (\\n) for example using dos2unix"
+
+    def check_rule(self, ctx, rule):
+        if len(rule.definition.split("\r\n")) > 0:
+            return False
+        return True
+
+
 class FormatSingleEmptyLineEOF(Lint):
     name = "EOF format"
     recommendation = "end file with a single empty line"
@@ -323,12 +335,43 @@ class FormatIncorrect(Lint):
 
         if actual != expected:
             diff = difflib.ndiff(actual.splitlines(1), expected.splitlines(True))
-            self.recommendation = self.recommendation_template.format("".join(diff))
+            recommendation_template = self.recommendation_template
+            if "\r\n" in actual:
+                recommendation_template = (
+                    self.recommendation_template + "\nplease make sure that the file uses LF (\\n) line endings only"
+                )
+            self.recommendation = recommendation_template.format("".join(diff))
             return True
 
         return False
 
 
+class FormatStringQuotesIncorrect(Lint):
+    name = "rule string quotes incorrect"
+
+    def check_rule(self, ctx, rule):
+        events = capa.rules.Rule._get_ruamel_yaml_parser().parse(rule.definition)
+        for key in events:
+            if not (isinstance(key, ruamel.yaml.ScalarEvent) and key.value == "string"):
+                continue
+            value = next(events)  # assume value is next event
+            if not isinstance(value, ruamel.yaml.ScalarEvent):
+                # ignore non-scalar
+                continue
+            if value.value.startswith("/") and value.value.endswith(("/", "/i")):
+                # ignore regex for now
+                continue
+            if value.style is None:
+                # no quotes
+                self.recommendation = 'add double quotes to "%s"' % value.value
+                return True
+            if value.style == "'":
+                # single quote
+                self.recommendation = 'change single quotes to double quotes for "%s"' % value.value
+                return True
+        return False
+
+
 def run_lints(lints, ctx, rule):
     for lint in lints:
         if lint.check_rule(ctx, rule):
@@ -387,7 +430,9 @@ def lint_features(ctx, rule):
 
 
 FORMAT_LINTS = (
+    FormatLineFeedEOL(),
     FormatSingleEmptyLineEOF(),
+    FormatStringQuotesIncorrect(),
     FormatIncorrect(),
 )
 
@@ -556,7 +601,7 @@ def main(argv=None):
 
     samples_path = os.path.join(os.path.dirname(__file__), "..", "tests", "data")
 
-    parser = argparse.ArgumentParser(description="A program.")
+    parser = argparse.ArgumentParser(description="Lint capa rules.")
     capa.main.install_common_args(parser, wanted={"tag"})
     parser.add_argument("rules", type=str, help="Path to rules")
     parser.add_argument("--samples", type=str, default=samples_path, help="Path to samples")
@@ -568,8 +613,12 @@ def main(argv=None):
     args = parser.parse_args(args=argv)
     capa.main.handle_common_args(args)
 
-    logging.getLogger("capa").setLevel(logging.CRITICAL)
+    if args.debug:
-    logging.getLogger("viv_utils").setLevel(logging.CRITICAL)
+        logging.getLogger("capa").setLevel(logging.DEBUG)
+        logging.getLogger("viv_utils").setLevel(logging.DEBUG)
+    else:
+        logging.getLogger("capa").setLevel(logging.ERROR)
+        logging.getLogger("viv_utils").setLevel(logging.ERROR)
 
     time0 = time.time()
 

setup.py

@@ -7,41 +7,25 @@
 # See the License for the specific language governing permissions and limitations under the License.
 
 import os
-import sys
 
 import setuptools
 
 requirements = [
-    "six",
+    "tqdm==4.60.0",
-    "tqdm",
+    "pyyaml==5.4.1",
-    "pyyaml",
+    "tabulate==0.8.9",
-    "tabulate",
+    "colorama==0.4.4",
-    "colorama",
+    "termcolor==1.1.0",
-    "termcolor",
+    "wcwidth==0.2.5",
-    "ruamel.yaml",
-    "wcwidth",
     "ida-settings==2.1.0",
+    "viv-utils==0.6.0",
+    "halo==0.0.31",
+    "networkx==2.5.1",
+    "ruamel.yaml==0.17.4",
+    "vivisect==1.0.1",
+    "smda==1.5.14",
 ]
 
-if sys.version_info >= (3, 0):
-    # py3
-    requirements.append("halo")
-    requirements.append("networkx")
-    requirements.append("vivisect==1.0.0")
-    requirements.append("viv-utils[flirt]==0.5.0")
-    requirements.append("smda==1.5.13")
-else:
-    # py2
-    requirements.append("enum34==1.1.6")  # v1.1.6 is needed by halo 0.0.30 / spinners 0.0.24
-    requirements.append("halo==0.0.30")  # halo==0.0.30 is the last version to support py2.7
-    requirements.append("vivisect==0.1.0")
-    # TODO: issue here with flirt not being supported.
-    # but we're also no longer supporting py2
-    # so this whole block goes away.
-    requirements.append("viv-utils==0.5.0")
-    requirements.append("networkx==2.2")  # v2.2 is last version supported by Python 2.7
-    requirements.append("backports.functools-lru-cache")
-
 # this sets __version__
 # via: http://stackoverflow.com/a/7071358/87207
 # and: http://stackoverflow.com/a/2073599/87207
@@ -80,13 +64,13 @@ setuptools.setup(
     install_requires=requirements,
     extras_require={
         "dev": [
-            "pytest",
+            "pytest==6.2.3",
-            "pytest-sugar",
+            "pytest-sugar==0.9.4",
-            "pytest-instafail",
+            "pytest-instafail==0.4.2",
-            "pytest-cov",
+            "pytest-cov==2.11.1",
-            "pycodestyle",
+            "pycodestyle==2.7.0",
-            "black ; python_version>'3.0'",
+            "black==21.4b0",
-            "isort",
+            "isort==5.8.0",
         ]
     },
     zip_safe=False,
@@ -97,8 +81,8 @@ setuptools.setup(
         "Intended Audience :: Information Technology",
         "License :: OSI Approved :: Apache Software License",
         "Natural Language :: English",
-        "Programming Language :: Python :: 2.7",
         "Programming Language :: Python :: 3",
         "Topic :: Security",
     ],
+    python_requires=">=3.6",
 )

tests/fixtures.py

@@ -8,7 +8,6 @@
 # See the License for the specific language governing permissions and limitations under the License.
 
 import os
-import sys
 import os.path
 import binascii
 import contextlib

tests/test_freeze.py

@@ -5,7 +5,6 @@
 # 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 textwrap
 
 import pytest
@@ -174,7 +173,6 @@ def test_serialize_features():
     roundtrip_feature(capa.features.file.Import("#11"))
 
 
-@pytest.mark.xfail(sys.version_info >= (3, 0), reason="vivsect only works on py2")
 def test_freeze_sample(tmpdir, z9324d_extractor):
     # tmpdir fixture handles cleanup
     o = tmpdir.mkdir("capa").join("test.frz").strpath
@@ -182,7 +180,6 @@ def test_freeze_sample(tmpdir, z9324d_extractor):
     assert capa.features.freeze.main([path, o, "-v"]) == 0
 
 
-@pytest.mark.xfail(sys.version_info >= (3, 0), reason="vivsect only works on py2")
 def test_freeze_load_sample(tmpdir, z9324d_extractor):
     o = tmpdir.mkdir("capa").join("test.frz")
 

tests/test_helpers.py

@@ -12,8 +12,6 @@ from capa.features.extractors import helpers
 
 
 def test_all_zeros():
-    # Python 2: <str>
-    # Python 3: <bytes>
     a = b"\x00\x00\x00\x00"
     b = codecs.decode("00000000", "hex")
     c = b"\x01\x00\x00\x00"

tests/test_main.py

@@ -6,7 +6,6 @@
 # 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 json
 import textwrap
 
@@ -58,10 +57,6 @@ def test_main_single_rule(z9324d_extractor, tmpdir):
 
 
 def test_main_non_ascii_filename(pingtaest_extractor, tmpdir, capsys):
-    # on py2.7, need to be careful about str (which can hold bytes)
-    #  vs unicode (which is only unicode characters).
-    # on py3, this should not be needed.
-    #
     # here we print a string with unicode characters in it
     # (specifically, a byte string with utf-8 bytes in it, see file encoding)
     assert capa.main.main(["-q", pingtaest_extractor.path]) == 0
@@ -69,20 +64,14 @@ def test_main_non_ascii_filename(pingtaest_extractor, tmpdir, capsys):
     std = capsys.readouterr()
     # but here, we have to use a unicode instance,
     # because capsys has decoded the output for us.
-    if sys.version_info >= (3, 0):
+    assert pingtaest_extractor.path in std.out
-        assert pingtaest_extractor.path in std.out
-    else:
-        assert pingtaest_extractor.path.decode("utf-8") in std.out
 
 
 def test_main_non_ascii_filename_nonexistent(tmpdir, caplog):
     NON_ASCII_FILENAME = "täst_not_there.exe"
     assert capa.main.main(["-q", NON_ASCII_FILENAME]) == -1
 
-    if sys.version_info >= (3, 0):
+    assert NON_ASCII_FILENAME in caplog.text
-        assert NON_ASCII_FILENAME in caplog.text
-    else:
-        assert NON_ASCII_FILENAME.decode("utf-8") in caplog.text
 
 
 def test_main_shellcode(z499c2_extractor):
@@ -91,6 +80,8 @@ def test_main_shellcode(z499c2_extractor):
     assert capa.main.main([path, "-v", "-f", "sc32"]) == 0
     assert capa.main.main([path, "-j", "-f", "sc32"]) == 0
     assert capa.main.main([path, "-f", "sc32"]) == 0
+    # auto detect shellcode based on file extension
+    assert capa.main.main([path]) == 0
 
 
 def test_ruleset():
@@ -370,16 +361,15 @@ def test_not_render_rules_also_matched(z9324d_extractor, capsys):
 
 # It tests main works with different backends
 def test_backend_option(capsys):
-    if sys.version_info > (3, 0):
+    path = get_data_path_by_name("pma16-01")
-        path = get_data_path_by_name("pma16-01")
+    assert capa.main.main([path, "-j", "-b", capa.main.BACKEND_VIV]) == 0
-        assert capa.main.main([path, "-j", "-b", capa.main.BACKEND_VIV]) == 0
+    std = capsys.readouterr()
-        std = capsys.readouterr()
+    std_json = json.loads(std.out)
-        std_json = json.loads(std.out)
+    assert std_json["meta"]["analysis"]["extractor"] == "VivisectFeatureExtractor"
-        assert std_json["meta"]["analysis"]["extractor"] == "VivisectFeatureExtractor"
+    assert len(std_json["rules"]) > 0
-        assert len(std_json["rules"]) > 0
 
-        assert capa.main.main([path, "-j", "-b", capa.main.BACKEND_SMDA]) == 0
+    assert capa.main.main([path, "-j", "-b", capa.main.BACKEND_SMDA]) == 0
-        std = capsys.readouterr()
+    std = capsys.readouterr()
-        std_json = json.loads(std.out)
+    std_json = json.loads(std.out)
-        assert std_json["meta"]["analysis"]["extractor"] == "SmdaFeatureExtractor"
+    assert std_json["meta"]["analysis"]["extractor"] == "SmdaFeatureExtractor"
-        assert len(std_json["rules"]) > 0
+    assert len(std_json["rules"]) > 0

tests/test_rules.py

@@ -681,6 +681,25 @@ def test_explicit_string_values_int():
     assert (String("0x123") in children) == True
 
 
+def test_string_values_special_characters():
+    rule = textwrap.dedent(
+        """
+        rule:
+            meta:
+                name: test rule
+            features:
+                - or:
+                    - string: "hello\\r\\nworld"
+                    - string: "bye\\nbye"
+                      description: "test description"
+        """
+    )
+    r = capa.rules.Rule.from_yaml(rule)
+    children = list(r.statement.get_children())
+    assert (String("hello\r\nworld") in children) == True
+    assert (String("bye\nbye") in children) == True
+
+
 def test_regex_values_always_string():
     rules = [
         capa.rules.Rule.from_yaml(

tests/test_smda_features.py

@@ -15,9 +15,9 @@ from fixtures import *
     FEATURE_PRESENCE_TESTS,
     indirect=["sample", "scope"],
 )
+@pytest.mark.xfail(sys.platform == "win32", reason="SMDA bug: https://github.com/danielplohmann/smda/issues/20")
 def test_smda_features(sample, scope, feature, expected):
-    with xfail(sys.version_info < (3, 0), reason="SMDA only works on py3"):
+    do_test_feature_presence(get_smda_extractor, sample, scope, feature, expected)
-        do_test_feature_presence(get_smda_extractor, sample, scope, feature, expected)
 
 
 @parametrize(
@@ -26,5 +26,4 @@ def test_smda_features(sample, scope, feature, expected):
     indirect=["sample", "scope"],
 )
 def test_smda_feature_counts(sample, scope, feature, expected):
-    with xfail(sys.version_info < (3, 0), reason="SMDA only works on py3"):
+    do_test_feature_count(get_smda_extractor, sample, scope, feature, expected)
-        do_test_feature_count(get_smda_extractor, sample, scope, feature, expected)