huntrule

AWS Bedrock Guardrail Updated via UpdateGuardrail API

Alerts on CloudTrail-reported Amazon Bedrock guardrail updates, which may signal attempts to weaken safety controls.

FreeReviewedSigma · Medium · v5
Product
aws
Service
cloudtrail
Author
Marco Pedrinazzi (@pedrinazziM) (InTheCyber) (SigmaHQ), DRL 1.1
Published
2026-07-10
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

  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 CloudTrail events where the Bedrock service reports an UpdateGuardrail action. Updating guardrails can be used to weaken or alter safety constraints, potentially enabling unsafe or unauthorized model outputs. It relies on AWS CloudTrail telemetry for the eventName and eventSource fields corresponding to Bedrock guardrail updates.

Reporting behind it

Related detections9 linkedT1685 — drag to rearrange
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Malicious Zemana Vulnerable Driver Load for EDR Termination (via image_load)
Suspicious EDRKillShifter Vulnerable Driver Load from User Temp Directory (via image_load)
Malicious AuKill EDR Killer Kernel Driver Load via Process Explorer Driver (via image_load)
Malicious FIN7 AvNeutralizer EDR Killer Execution via Masqueraded Binary (via process_creation)
Suspicious Process Explorer Kernel Driver Dropped as PED.sys via File Creation (via file_event)
Malicious Windows Defender Tampering via Set-MpPreference and Add-MpPreference (via ps_script)
AWS Bedrock Guardrail Updated via UpdateGuardrail API
Pivot detection · T1685 · 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.