name: GitHub Pull Request from Unknown User
id: 9d7b9100-8878-4404-914e-ca5e551a641e
version: 6
creation_date: '2021-09-01'
modification_date: '2026-05-13'
author: Patrick Bareiss, Splunk
status: removed
type: Anomaly
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.
data_source:
    - GitHub Webhooks
search: '`github` check_suite.pull_requests{}.id=* | stats count by check_suite.head_commit.author.name repository.full_name check_suite.pull_requests{}.head.ref check_suite.head_commit.message | 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 | search NOT `github_known_users` | eval phase="code" | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `github_pull_request_from_unknown_user_filter`'
how_to_implement: You must index GitHub logs. You can follow the url in reference to onboard GitHub logs.
known_false_positives: unknown
references:
    - https://www.splunk.com/en_us/blog/tips-and-tricks/getting-github-data-with-webhooks.html
drilldown_searches:
    - name: View the detection results for - "$repository$"
      search: '%original_detection_search% | search  repository = "$repository$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$repository$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$repository$") starthoursago=168  | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
rba:
    message: Vulnerabilities found in packages used by GitHub repository $repository$
    risk_objects:
        - field: repository
          type: other
          score: 27
    threat_objects: []
tags:
    analytic_story:
        - Dev Sec Ops
    asset_type: GitHub
    mitre_attack_id:
        - T1195.001
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: network
tests:
    - name: True Positive Test
      attack_data:
          - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1195.001/github_pull_request/github_pull_request.json
            sourcetype: aws:firehose:json
            source: github
deprecation_info:
    reason: Detection deprecated as it no longer effectively identifies the intended malicious activity
    removed_in_version: 5.4.0
    replacement_content: []