AWS Bedrock Guardrail Deletion via CloudTrail DeleteGuardrail API

Alerts on CloudTrail DeleteGuardrail events indicating an AWS Bedrock guardrail was removed.

FreeReviewedSigma · Medium · v5

Product: aws
Service: cloudtrail
Author: Marco Pedrinazzi (@pedrinazziM) (InTheCyber) (SigmaHQ), DRL 1.1
Published: 2026-07-10
Updated: 2026-07-31

ATT&CK techniques

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags CloudTrail events where the Bedrock service reports a DeleteGuardrail API call. Deleting a guardrail can reduce or remove model safety controls, which may enable unsafe or unauthorized responses. It relies on AWS CloudTrail telemetry for eventName DeleteGuardrail with eventSource bedrock.amazonaws.com.

Reporting behind it

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AWS Bedrock Guardrail Deletion via CloudTrail DeleteGuardrail API

Pivot detection · T1685 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
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.

aws-bedrock-guardrail-deletion-via-cloudtrail-deleteguardrail-api-call-59b70e4d

title: AWS Bedrock Guardrail Deletion via CloudTrail DeleteGuardrail API
id: 5bcde200-5145-4008-9c58-e3a489daf4c6
status: experimental
description: This rule flags CloudTrail events where the Bedrock service reports a DeleteGuardrail API call. Deleting a guardrail can reduce or remove model safety controls, which may enable unsafe or unauthorized responses. It relies on AWS CloudTrail telemetry for eventName DeleteGuardrail with eventSource bedrock.amazonaws.com.
references:
  - https://docs.aws.amazon.com/bedrock/latest/APIReference/API_DeleteGuardrail.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/aws/cloudtrail/aws_cloudtrail_bedrock_guardrail_deleted.yml
author: Marco Pedrinazzi (@pedrinazziM) (InTheCyber), Huntrule Team
date: 2026-07-10
tags:
  - attack.defense-impairment
  - attack.t1685
logsource:
  product: aws
  service: cloudtrail
detection:
  selection:
    eventName: DeleteGuardrail
    eventSource: bedrock.amazonaws.com
  condition: selection
falsepositives:
  - Legitimate guardrail deletion by authorized identities.
level: medium
license: DRL-1.1
related:
  - id: 59b70e4d-dd17-44a9-b740-acf07ae3eb6a
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

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