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# GWS - Google Platforms Phishing
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{{#include ../../../banners/hacktricks-training.md}}
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## Generic Phishing Methodology
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{{#ref}}
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https://book.hacktricks.xyz/generic-methodologies-and-resources/phishing-methodology
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{{#endref}}
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## Google Groups Phishing
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Apparently, by default, in workspace members [**can create groups**](https://groups.google.com/all-groups) **and invite people to them**. You can then modify the email that will be sent to the user **adding some links.** The **email will come from a google address**, so it will look **legit** and people might click on the link.
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It's also possible to set the **FROM** address as the **Google group email** to send **more emails to the users inside the group**, like in the following image where the group **`google--support@googlegroups.com`** was created and an **email was sent to all the members** of the group (that were added without any consent)
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<figure><img src="../../../images/image (5) (1).png" alt=""><figcaption></figcaption></figure>
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## Google Chat Phishing
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You might be able to either **start a chat** with a person just having their email address or send an **invitation to talk**. Moreover, it's possible to **create a Space** that can have any name (e.g. "Google Support") and **invite** members to it. If they accept they might think that they are talking to Google Support:
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<figure><img src="../../../images/image (6).png" alt=""><figcaption></figcaption></figure>
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> [!TIP]
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> **In my testing however the invited members didn't even receive an invitation.**
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You can check how this worked in the past in: [https://www.youtube.com/watch?v=KTVHLolz6cE\&t=904s](https://www.youtube.com/watch?v=KTVHLolz6cE&t=904s)
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## Google Doc Phishing
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In the past it was possible to create an **apparently legitimate document** and the in a comment **mention some email (like @user@gmail.com)**. Google **sent an email to that email address** notifying that they were mentioned in the document.\
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Nowadays, this doesn't work but if you **give the victim email access to the document** Google will send an email indicating so. This is the message that appears when you mention someone:
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<figure><img src="../../../images/image (7).png" alt=""><figcaption></figcaption></figure>
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> [!TIP]
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> Victims might have protection mechanism that doesn't allow that emails indicating that an external document was shared with them reach their email.
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## Google Calendar Phishing
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You can **create a calendar event** and add as many email address of the company you are attacking as you have. Schedule this calendar event in **5 or 15 min** from the current time. Make the event look legit and **put a comment and a title indicating that they need to read something** (with the **phishing link**).
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This is the alert that will appear in the browser with a meeting title "Firing People", so you could set a more phishing like title (and even change the name associated with your email).
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<figure><img src="../../../images/image (8).png" alt=""><figcaption></figcaption></figure>
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To make it look less suspicious:
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- Set it up so that **receivers cannot see the other people invited**
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- Do **NOT send emails notifying about the event**. Then, the people will only see their warning about a meeting in 5mins and that they need to read that link.
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- Apparently using the API you can set to **True** that **people** have **accepted** the event and even create **comments on their behalf**.
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## App Scripts Redirect Phishing
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It's possible to create a script in [https://script.google.com/](https://script.google.com/) and **expose it as a web application accessible by everyone** that will use the legit domain **`script.google.com`**.\
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The with some code like the following an attacker could make the script load arbitrary content in this page without stop accessing the domain:
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```javascript
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function doGet() {
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return HtmlService.createHtmlOutput(
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'<meta http-equiv="refresh" content="0;url=https://cloud.hacktricks.xyz/pentesting-cloud/workspace-security/gws-google-platforms-phishing#app-scripts-redirect-phishing">'
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).setXFrameOptionsMode(HtmlService.XFrameOptionsMode.ALLOWALL)
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}
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```
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For example accessing [https://script.google.com/macros/s/AKfycbwuLlzo0PUaT63G33MtE6TbGUNmTKXCK12o59RKC7WLkgBTyltaS3gYuH_ZscKQTJDC/exec](https://script.google.com/macros/s/AKfycbwuLlzo0PUaT63G33MtE6TbGUNmTKXCK12o59RKC7WLkgBTyltaS3gYuH_ZscKQTJDC/exec) you will see:
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<figure><img src="../../../images/image (4) (1).png" alt=""><figcaption></figcaption></figure>
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> [!TIP]
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> Note that a warning will appear as the content is loaded inside an iframe.
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## App Scripts OAuth Phishing
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It's possible to create App Scripts attached to documents to try to get access over a victims OAuth token, for more information check:
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{{#ref}}
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gws-app-scripts.md
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{{#endref}}
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## OAuth Apps Phishing
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Any of the previous techniques might be used to make the user access a **Google OAuth application** that will **request** the user some **access**. If the user **trusts** the **source** he might **trust** the **application** (even if it's asking for high privileged permissions).
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> [!NOTE]
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> Note that Google presents an ugly prompt asking warning that the application is untrusted in several cases and Workspace admins can even prevent people accepting OAuth applications.
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**Google** allows to create applications that can **interact on behalf users** with several **Google services**: Gmail, Drive, GCP...
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When creating an application to **act on behalf other users**, the developer needs to create an **OAuth app inside GCP** and indicate the scopes (permissions) the app needs to access the users data.\
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When a **user** wants to **use** that **application**, they will be **prompted** to **accept** that the application will have access to their data specified in the scopes.
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This is a very juicy way to **phish** non-technical users into using **applications that access sensitive information** because they might not understand the consequences. However, in organizations accounts, there are ways to prevent this from happening.
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### Unverified App prompt
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As it was mentioned, google will always present a **prompt to the user to accept** the permissions they are giving the application on their behalf. However, if the application is considered **dangerous**, google will show **first** a **prompt** indicating that it's **dangerous** and **making it more difficult** for the user to grant the permissions to the app.
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This prompt appears in apps that:
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- Use any scope that can access private data (Gmail, Drive, GCP, BigQuery...)
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- Apps with less than 100 users (apps > 100 a review process is also needed to stop showing the unverified prompt)
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### Interesting Scopes
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[**Here**](https://developers.google.com/identity/protocols/oauth2/scopes) you can find a list of all the Google OAuth scopes.
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- **cloud-platform**: View and manage your data across **Google Cloud Platform** services. You can impersonate the user in GCP.
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- **admin.directory.user.readonly**: See and download your organization's GSuite directory. Get names, phones, calendar URLs of all the users.
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### Create an OAuth App
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**Start creating an OAuth Client ID**
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1. Go to [https://console.cloud.google.com/apis/credentials/oauthclient](https://console.cloud.google.com/apis/credentials/oauthclient) and click on configure the consent screen.
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2. Then, you will be asked if the **user type** is **internal** (only for people in your org) or **external**. Select the one that suits your needs
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- Internal might be interesting you have already compromised a user of the organization and you are creating this App to phish another one.
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3. Give a **name** to the app, a **support email** (note that you can set a googlegroup email to try to anonymize yourself a bit more), a **logo**, **authorized domains** and another **email** for **updates**.
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4. **Select** the **OAuth scopes**.
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- This page is divided in non sensitive permissions, sensitive permissions and restricted permissions. Eveytime you add a new permisison it's added on its category. Depending on the requested permissions different prompt will appear to the user indicating how sensitive these permissions are.
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- Both **`admin.directory.user.readonly`** and **`cloud-platform`** are sensitive permissions.
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5. **Add the test users.** As long as the status of the app is testing, only these users are going to be able to access the app so make sure to **add the email you are going to be phishing**.
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Now let's get **credentials for a web application** using the **previously created OAuth Client ID**:
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1. Go back to [https://console.cloud.google.com/apis/credentials/oauthclient](https://console.cloud.google.com/apis/credentials/oauthclient), a different option will appear this time.
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2. Select to **create credentials for a Web application**
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3. Set needed **Javascript origins** and **redirect URIs**
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- You can set in both something like **`http://localhost:8000/callback`** for testing
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4. Get your application **credentials**
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Finally, lets **run a web application that will use the OAuth application credentials**. You can find an example in [https://github.com/carlospolop/gcp_oauth_phishing_example](https://github.com/carlospolop/gcp_oauth_phishing_example).
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```bash
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git clone ttps://github.com/carlospolop/gcp_oauth_phishing_example
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cd gcp_oauth_phishing_example
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pip install flask requests google-auth-oauthlib
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python3 app.py --client-id "<client_id>" --client-secret "<client_secret>"
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```
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Go to **`http://localhost:8000`** click on the Login with Google button, you will be **prompted** with a message like this one:
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<figure><img src="../../../images/image (333).png" alt=""><figcaption></figcaption></figure>
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The application will show the **access and refresh token** than can be easily used. For more information about **how to use these tokens check**:
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{{#ref}}
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../../gcp-security/gcp-persistence/gcp-non-svc-persistance.md
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{{#endref}}
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#### Using `glcoud`
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It's possible to do something using gcloud instead of the web console, check:
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{{#ref}}
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../../gcp-security/gcp-privilege-escalation/gcp-clientauthconfig-privesc.md
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{{#endref}}
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## References
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- [https://www.youtube-nocookie.com/embed/6AsVUS79gLw](https://www.youtube-nocookie.com/embed/6AsVUS79gLw) - Matthew Bryant - Hacking G Suite: The Power of Dark Apps Script Magic
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- [https://www.youtube.com/watch?v=KTVHLolz6cE](https://www.youtube.com/watch?v=KTVHLolz6cE) - Mike Felch and Beau Bullock - OK Google, How do I Red Team GSuite?
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{{#include ../../../banners/hacktricks-training.md}}
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