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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.

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-05-29
  • Author: Patrick Bareiss, Splunk
  • ID: 1f0b47e5-0134-43eb-851c-e3258638945e

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1562.008 Disable or Modify Cloud Logs Defense Evasion
T1562 Impair Defenses Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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`amazon_security_lake` api.operation=DeleteTrail 
| fillnull 
| stats count min(_time) as firstTime max(_time) as lastTime by api.operation actor.user.account_uid actor.user.uid http_request.user_agent src_endpoint.ip cloud.region 
| rename actor.user.uid as user, src_endpoint.ip as src_ip, cloud.region as region, http_request.user_agent as user_agent, actor.user.account_uid as aws_account_id   
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `asl_aws_defense_evasion_delete_cloudtrail_filter`

Macros

The SPL above uses the following Macros:

:information_source: asl_aws_defense_evasion_delete_cloudtrail_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • api.operation
  • actor.user.account_uid
  • actor.user.name
  • actor.user.uid
  • http_request.user_agent
  • src_endpoint.ip
  • cloud.region

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.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
90.0 100 90 User $user$ has deleted a CloudTrail logging for account id $aws_account_id$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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 | version: 4