huntrule

GCP Audit Logs: Access Context Manager Access Policy Deletion

Flags GCP Access Context Manager audit events where granted access policy delete permissions occur.

FreeReviewedSigma · Medium · v5
Product
gcp
Service
gcp.audit
Author
Bryan Lim (SigmaHQ), DRL 1.1
Published
2024-01-12
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Persistence → Priv Esc

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags GCP Access Context Manager audit events where an access policy or related objects are deleted by a caller with granted authorization. Deleting access policies can remove enforcement and may enable an attacker to gain or expand access to protected GCP resources. It relies on GCP audit log telemetry from the accesscontextmanager.googleapis.com service and matches specific delete permissions with granted=true in protoPayload authorizationInfo.

Reporting behind it

Related detections9 linkedT1098 — drag to rearrange
Malicious Cluster-Admin Role Binding Creation (via audit)
Malicious User Password Change Using Current Hash Password - ChangeNTLM - Mimikatz (via security)
Suspicious Account Password Set to Never Expire. (via security)
Malicious Modification of a Computer Account SPN (via security)
Suspicious Massive Group Membership Changes (via security)
Malicious High Risk Active Directory Group Membership Change (via security)
Malicious Account Marked as Sensitive and Cannot Be Delegated Had Its Protection Removed (via security)
Malicious Host Constrained Delegation Settings Changed for Potential Abuse (Rubeus) - Kerberos Only (via security)
Malicious Host Set with Unconstrained Delegation (via security)
GCP Audit Logs: Access Context Manager Access Policy Deletion
Pivot detection · T1098 · 9 related

Changelog

v5
  1. v5
    Candidate ingested via manual entry.2026-07-31
  2. v4
    Candidate ingested via manual entry.2026-07-31
  3. v3
    Candidate ingested via manual entry.2026-07-31
  4. v2
    Candidate ingested via manual entry.2026-07-31
  5. v1
    No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.