Detection rules › Splunk

ASL AWS Defense Evasion Delete 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 AWS DeleteTrail events within CloudTrail logs. It leverages Amazon Security Lake logs parsed in the Open Cybersecurity Schema Framework (OCSF) format to identify when a CloudTrail is deleted. This activity is significant because adversaries may delete CloudTrail logs to evade detection and operate with stealth. If confirmed malicious, this action could allow attackers to cover their tracks, making it difficult to trace their activities and investigate other potential compromises within the AWS environment.

MITRE ATT&CK coverage

Rules detecting the same action

Other rules on this platform that filter on the same API call or operation.

Rule body splunk

name: ASL AWS Defense Evasion Delete Cloudtrail
id: 1f0b47e5-0134-43eb-851c-e3258638945e
version: 14
creation_date: '2022-07-12'
modification_date: '2026-05-13'
author: Patrick Bareiss, Splunk
status: production
type: TTP
description: The following analytic detects AWS `DeleteTrail` events within CloudTrail logs. It leverages Amazon Security Lake logs parsed in the Open Cybersecurity Schema Framework (OCSF) format to identify when a CloudTrail is deleted. This activity is significant because adversaries may delete CloudTrail logs to evade detection and operate with stealth. If confirmed malicious, this action could allow attackers to cover their tracks, making it difficult to trace their activities and investigate other potential compromises within the AWS environment.
data_source:
    - ASL AWS CloudTrail
search: |-
    `amazon_security_lake` api.operation=DeleteTrail
      | 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_delete_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/
drilldown_searches:
    - name: View the detection results for - "$user$"
      search: '%original_detection_search% | search  user = "$user$"'
      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 ("$user$") | 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: 7d
      latest_offset: "0"
finding:
    title: User $user$ has deleted CloudTrail logging
    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
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.008/stop_delete_cloudtrail/asl_ocsf_cloudtrail.json
          sourcetype: aws:asl
          source: aws_asl
      test_type: unit

Stages and Predicates

Stage 1: search

`amazon_security_lake` api.operation=DeleteTrail

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_delete_cloudtrail_filter`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
api.operationeq
  • DeleteTrail
sourcetypeeq
  • aws:asl