Suspicious Removal of GCP Access Policy (via gcp.audit)

title: Suspicious Removal of GCP Access Policy (via gcp.audit)
id: 4ae70793-849f-52f0-afc9-c47986d4f4bd
status: stable
description: This rule detects when an access policy that is applied to a GCP cloud resource is deleted. An adversary would be able to remove access policies to gain access to a GCP cloud resource.
references:
    - https://attack.mitre.org/techniques/T1098/
    - https://cloud.google.com/access-context-manager/docs/audit-logging
    - https://cloud.google.com/logging/docs/audit/understanding-audit-logs
    - https://cloud.google.com/logging/docs/reference/audit/auditlog/rest/Shared.Types/AuditLog
author: Huntrule Team
date: 2026-03-05
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.t1098
logsource:
    product: gcp
    service: gcp.audit
detection:
    selection:
        data.protoPayload.authorizationInfo.permission:
            - 'accesscontextmanager.accessPolicies.delete'
            - 'accesscontextmanager.accessPolicies.accessLevels.delete'
            - 'accesscontextmanager.accessPolicies.accessZones.delete'
            - 'accesscontextmanager.accessPolicies.authorizedOrgsDescs.delete'
        data.protoPayload.authorizationInfo.granted: 'true'
        data.protoPayload.serviceName: 'accesscontextmanager.googleapis.com'
    condition: selection
falsepositives:
    - Unknown
level: medium