ASL AWS Credential Access RDS Password reset

name: ASL AWS Credential Access RDS Password reset
id: d15e9bd9-ef64-4d84-bc04-f62955a9fee8
version: 7
date: '2026-03-10'
author: Patrick Bareiss, Splunk
status: production
type: TTP
description: The following analytic detects the resetting of the master user password for an Amazon RDS DB instance. It leverages AWS CloudTrail logs from Amazon Security Lake to identify events where the `ModifyDBInstance` API call includes a new `masterUserPassword` parameter. This activity is significant because unauthorized password resets can grant attackers access to sensitive data stored in production databases, such as credit card information, PII, and healthcare data. If confirmed malicious, this could lead to data breaches, regulatory non-compliance, and significant reputational damage. Immediate investigation is required to determine the legitimacy of the password reset.
data_source:
    - ASL AWS CloudTrail
search: |-
    `amazon_security_lake` api.operation=ModifyDBInstance OR api.operation=ModifyDBCluster
      | spath input=api.request.data
      | search masterUserPassword=*
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY actor.user.uid api.operation api.service.name
           http_request.user_agent src_endpoint.ip actor.user.account.uid
           cloud.provider cloud.region api.request.data
      | rename actor.user.uid as user api.operation as action api.service.name as dest http_request.user_agent as user_agent src_endpoint.ip as src actor.user.account.uid as vendor_account cloud.provider as vendor_product cloud.region as vendor_region
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `asl_aws_credential_access_rds_password_reset_filter`
how_to_implement: The detection is based on Amazon Security Lake events from Amazon Web Services (AWS), which is a centralized data lake that provides security-related data from AWS services. To use this detection, you must ingest CloudTrail logs from Amazon Security Lake into Splunk. To run this search, ensure that you ingest events using the latest version of Splunk Add-on for Amazon Web Services (https://splunkbase.splunk.com/app/1876) or the Federated Analytics App.
known_false_positives: Users may genuinely reset the RDS password.
references:
    - https://aws.amazon.com/premiumsupport/knowledge-center/reset-master-user-password-rds
drilldown_searches:
    - name: View the detection results for - "$user$"
      search: '%original_detection_search% | search  database_id = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") starthoursago=168  | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
rba:
    message: User $user$ is seen to reset the password for database
    risk_objects:
        - field: user
          type: user
          score: 50
    threat_objects:
        - field: src
          type: ip_address
tags:
    analytic_story:
        - AWS Identity and Access Management Account Takeover
        - Scattered Lapsus$ Hunters
    asset_type: AWS Account
    mitre_attack_id:
        - T1110
        - T1586.003
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: threat
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1110.002/aws_rds_password_reset/asl_ocsf_cloudtrail.json
          sourcetype: aws:asl
          source: aws_asl