Detection: GitHub Pull Request from Unknown User

REMOVED DETECTION

This detection has been removed from the Splunk Threat Research content library and is no longer maintained or supported.

Reason: Detection deprecated as it no longer effectively identifies the intended malicious activity

Removed in version: 5.4.0

If you have any questions or concerns, please reach out to us at research@splunk.com.

Updated Date: 2026-05-13 ID: 9d7b9100-8878-4404-914e-ca5e551a641e Author: Patrick Bareiss, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects pull requests from unknown users on GitHub. It uses a Splunk query to identify pull requests where the user ID is not specified and cross-references these with a known users lookup table. This activity is significant because pull requests from unknown users can introduce malicious code or unauthorized changes to repositories. If confirmed malicious, this could lead to unauthorized code changes, data breaches, or other security incidents. Immediate steps include reviewing the author's name, repository, head reference, and commit message, and investigating any related artifacts and processes.

Search

1`github` check_suite.pull_requests{}.id=* 
2| stats count by check_suite.head_commit.author.name repository.full_name check_suite.pull_requests{}.head.ref check_suite.head_commit.message 
3| rename check_suite.head_commit.author.name as user repository.full_name as repository check_suite.pull_requests{}.head.ref as ref_head check_suite.head_commit.message as commit_message 
4| search NOT `github_known_users` 
5| eval phase="code" 
6| `security_content_ctime(firstTime)` 
7| `security_content_ctime(lastTime)` 
8| `github_pull_request_from_unknown_user_filter`

Data Source

Name	Platform	Sourcetype	Source
GitHub Webhooks	AWS	`'aws:firehose:json'`	`'github'`

Macros Used

Name	Value
github	`sourcetype=aws:firehose:json`
github_pull_request_from_unknown_user_filter	``

github_pull_request_from_unknown_user_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1195.001

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`N/A`
Earliest Time	`N/A`
Latest Time	`N/A`
Schedule Window	`N/A`
Creates Finding (Notable)	No
Creates Intermediate Finding (Risk Event)	No

Anomaly detections generate Intermediate Findings (Risk Events). They do not generate a Finding (Notable) directly.

Implementation

You must index GitHub logs. You can follow the url in reference to onboard GitHub logs.

Known False Positives

unknown

Associated Analytic Story

Dev Sec Ops

References

https://www.splunk.com/en_us/blog/tips-and-tricks/getting-github-data-with-webhooks.html

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	Not Applicable	N/A	N/A	N/A
Unit	Not Applicable	N/A	`N/A`	`N/A`
Integration	Not Applicable	N/A	`N/A`	`N/A`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub |

Version: 6