GitHub Audit: Outside Collaborator Membership and Permission Changes

Alerts on GitHub audit events involving outside collaborators being removed or permission changes on projects.

FreeReviewedSigma · Medium · v5
Product
github
Service
audit
Author
Muhammad Faisal (@faisalusuf) (SigmaHQ), DRL 1.1
Published
2023-01-20
Updated
2026-07-31
title: "GitHub Audit: Outside Collaborator Membership and Permission Changes"
id: 29ef7873-9ffa-4ce6-a1c5-6fae79382c98
status: test
description: This rule flags GitHub audit log events where an outside collaborator is removed or where a user’s project board permissions are updated. Such changes can be used to reduce access for defenders or alter project access to support persistence and data collection. The detection relies on GitHub audit events for collaborator removal and project permission updates, including the associated actor and organization/project context.
author: Muhammad Faisal (@faisalusuf), Huntrule Team
date: 2023-01-20
references:
  - https://docs.github.com/en/organizations/keeping-your-organization-secure/managing-security-settings-for-your-organization/reviewing-the-audit-log-for-your-organization#audit-log-actions
  - https://docs.github.com/en/organizations/keeping-your-organization-secure/managing-two-factor-authentication-for-your-organization/requiring-two-factor-authentication-in-your-organization
  - https://github.com/SigmaHQ/sigma/blob/master/rules/application/github/audit/github_outside_collaborator_detected.yml
tags:
  - attack.privilege-escalation
  - attack.persistence
  - attack.collection
  - attack.t1098.001
  - attack.t1098.003
  - attack.t1213.003
logsource:
  product: github
  service: audit
  definition: "Requirements: The audit log streaming feature must be enabled to be able to receive such logs. You can enable following the documentation here: https://docs.github.com/en/enterprise-cloud@latest/admin/monitoring-activity-in-your-enterprise/reviewing-audit-logs-for-your-enterprise/streaming-the-audit-log-for-your-enterprise#setting-up-audit-log-streaming"
detection:
  selection:
    action:
      - org.remove_outside_collaborator
      - project.update_user_permission
  condition: selection
falsepositives:
  - Validate the actor if permitted to access the repo.
  - Validate the Multifactor Authentication changes.
level: medium
license: DRL-1.1
related:
  - id: eaa9ac35-1730-441f-9587-25767bde99d7
    type: derived