huntrule

GCP Kubernetes audit events: Admission webhook configuration creates/updates

Flags GCP Kubernetes audit events indicating mutating/validating admission webhook configuration create/patch/replace activity.

FreeReviewedSigma · Medium · v4
Product
gcp
Service
gcp.audit
Author
Austin Songer @austinsonger (SigmaHQ), DRL 1.1
Published
2021-11-25
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Initial Access → Cred Access

  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 identifies Kubernetes admission webhook configuration changes in Google Cloud by matching audit method names under admissionregistration.k8s.io for mutating and validating webhooks. Attackers can leverage these webhooks to intercept or modify API requests, enabling persistence, stealthy execution, and potential credential or secret capture. Telemetry is based on GCP audit log method_name values corresponding to create, patch, or replace operations on mutatingwebhookconfigurations or validatingwebhookconfigurations.

Reporting behind it

Related detections9 linkedT1078 — drag to rearrange
Kubernetes API Audit: Admission Webhook Configuration Modified
Azure Activity Logs: Kubernetes AdmissionRegistration webhook configuration writes
Suspicious Self-Hosted GitHub Actions Runner Started As Root via Shell (via process_creation)
Suspicious Login Shell Assigned to Service Account games on Linux
Suspicious SSH Daemon Configuration Change Enabling Root Login
Suspicious AWS API Call from TruffleHog Credential Scanner User Agent
Suspicious NTLM Network Logon From Attacker Controlled Workstation Names (via security)
Suspicious dMSA Object Access with Migration AccessMask
Suspicious Access To Kubernetes Service Account Token File
GCP Kubernetes audit events: Admission webhook configuration creates/updates
Pivot detection · T1078 · 9 related

Changelog

v4
  1. v4
    Candidate ingested via manual entry.2026-07-31
  2. v3
    Candidate ingested via manual entry.2026-07-31
  3. v2
    Candidate ingested via manual entry.2026-07-31
  4. 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.