AWS CloudTrail RDS ModifyDBInstance Master User Password Change

Flags AWS RDS ModifyDBInstance events that include a master user password change.

FreeReviewedSigma · Medium · v5
Product
aws
Service
cloudtrail
Author
faloker (SigmaHQ), DRL 1.1
Published
2020-02-12
Updated
2026-07-31
title: AWS CloudTrail RDS ModifyDBInstance Master User Password Change
id: 8c1a1505-ffb1-4205-be11-ce262cdcc44d
status: test
description: This rule identifies CloudTrail events where an Amazon RDS DB instance is modified and the pending master user password field is present in the response. Attackers may change the RDS master password as part of data theft or post-access persistence to lock out legitimate credentials. The detection relies on AWS CloudTrail ModifyDBInstance telemetry and matching response elements that indicate the master password value was targeted for modification.
references:
  - https://github.com/RhinoSecurityLabs/pacu/blob/866376cd711666c775bbfcde0524c817f2c5b181/pacu/modules/rds__explore_snapshots/main.py
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/aws/cloudtrail/aws_rds_change_master_password.yml
author: faloker, Huntrule Team
date: 2020-02-12
modified: 2022-10-05
tags:
  - attack.exfiltration
  - attack.t1020
logsource:
  product: aws
  service: cloudtrail
detection:
  selection_source:
    eventSource: rds.amazonaws.com
    responseElements.pendingModifiedValues.masterUserPassword|contains: "*"
    eventName: ModifyDBInstance
  condition: selection_source
falsepositives:
  - Benign changes to a db instance
level: medium
license: DRL-1.1
related:
  - id: 8a63cdd4-6207-414a-85bc-7e032bd3c1a2
    type: derived