Detection rules › Splunk

ASL AWS Defense Evasion Stop Logging Cloudtrail

Status
production
Severity
medium
Group by
"actor.user.account.uid", "actor.user.uid", "api.operation", "api.service.name", "cloud.provider", "cloud.region", "http_request.user_agent", "src_endpoint.ip"
Author
Patrick Bareiss, Splunk
Source
github.com/splunk/security_content

The following analytic detects StopLogging events within AWS CloudTrail logs, a critical action that adversaries may use to evade detection. By halting the logging of their malicious activities, attackers aim to operate undetected within a compromised AWS environment. This detection is achieved by monitoring for specific CloudTrail log entries that indicate the cessation of logging activities. Identifying such behavior is crucial for a Security Operations Center (SOC), as it signals an attempt to undermine the integrity of logging mechanisms, potentially allowing malicious activities to proceed without observation. The impact of this evasion tactic is significant, as it can severely hamper incident response and forensic investigations by obscuring the attacker's actions.

Known false positives

  • While this search has no known false positives, it is possible that an AWS admin has stopped cloudtrail logging. Please investigate this activity.

MITRE ATT&CK coverage

Telemetry coverage

Rules detecting the same action

These rules filter on the same operation.

Rule body

name: ASL AWS Defense Evasion Stop Logging Cloudtrail
id: 0b78a8f9-1d31-4d23-85c8-56ad13d5b4c1
version: 12
creation_date: '2024-05-22'
modification_date: '2026-05-13'
author: Patrick Bareiss, Splunk
status: production
type: TTP
description: The following analytic detects `StopLogging` events within AWS CloudTrail logs, a critical action that adversaries may use to evade detection. By halting the logging of their malicious activities, attackers aim to operate undetected within a compromised AWS environment. This detection is achieved by monitoring for specific CloudTrail log entries that indicate the cessation of logging activities. Identifying such behavior is crucial for a Security Operations Center (SOC), as it signals an attempt to undermine the integrity of logging mechanisms, potentially allowing malicious activities to proceed without observation. The impact of this evasion tactic is significant, as it can severely hamper incident response and forensic investigations by obscuring the attacker's actions.
data_source:
    - ASL AWS CloudTrail
search: |-
    `amazon_security_lake` api.operation=StopLogging
      | 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
      | 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_defense_evasion_stop_logging_cloudtrail_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: While this search has no known false positives, it is possible that an AWS admin has stopped cloudtrail logging. Please investigate this activity.
references:
    - https://attack.mitre.org/techniques/T1562/008/
finding:
    title: User $user$ has stopped Cloudtrail logging for account id $vendor_account$ from IP $src$
    entity:
        field: user
        type: user
        score: 50
threat_objects:
    - field: src
      type: ip_address
analytic_story:
    - AWS Defense Evasion
asset_type: AWS Account
mitre_attack_id:
    - T1685.002
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: threat

Stages and Predicates

Stage 1: search

`amazon_security_lake` api.operation=StopLogging

Stage 2: fillnull

| fillnull

Stage 3: stats

| 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

Stage 4: rename

| 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

Stage 5: search

| `security_content_ctime(firstTime)`

Stage 6: search

| `security_content_ctime(lastTime)`

Stage 7: search

| `asl_aws_defense_evasion_stop_logging_cloudtrail_filter`

Indicators

These rows show field, operator, and value matches.