Detection: ASL AWS Credential Access RDS Password reset

Updated Date: 2024-12-12 ID: d15e9bd9-ef64-4d84-bc04-f62955a9fee8 Author: Patrick Bareiss, Splunk Type: TTP Product: Splunk Enterprise Security

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.

1`amazon_security_lake` api.operation=ModifyDBInstance OR api.operation=ModifyDBCluster 
2| spath input=api.request.data 
3| search masterUserPassword=* 
4| fillnull 
5| stats count min(_time) as firstTime max(_time) as lastTime by api.operation actor.user.uid actor.user.account.uid http_request.user_agent src_endpoint.ip cloud.region api.request.data 
6| rename actor.user.uid as user, src_endpoint.ip as src_ip, cloud.region as region, http_request.user_agent as user_agent 
7| `security_content_ctime(firstTime)` 
8| `security_content_ctime(lastTime)` 
9|`asl_aws_credential_access_rds_password_reset_filter`

Data Source

Name Platform Sourcetype Source
ASL AWS CloudTrail AWS icon AWS 'aws:asl' 'aws_asl'

Macros Used

Name Value
amazon_security_lake sourcetype=aws:asl
asl_aws_credential_access_rds_password_reset_filter search *
asl_aws_credential_access_rds_password_reset_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1586 Compromise Accounts Resource Development
T1586.003 Cloud Accounts Resource Development
T1110 Brute Force Credential Access
Exploitation
Weaponization
DE.CM
CIS 10
APT29
APT28
APT38
APT39
APT41
Agrius
DarkVishnya
Dragonfly
Ember Bear
FIN5
Fox Kitten
HEXANE
OilRig
Turla

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

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.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

User $user$ is seen to reset the password for database

Risk Object Risk Object Type Risk Score Threat Objects
user user 49 src_ip

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset aws_asl aws:asl
Integration ✅ Passing Dataset aws_asl aws:asl

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 1