ASL AWS Defense Evasion PutBucketLifecycle

name: ASL AWS Defense Evasion PutBucketLifecycle
id: 986565a2-7707-48ea-9590-37929cebc938
version: 5
date: '2026-02-25'
author: Patrick Bareiss, Splunk
status: production
type: Hunting
description: The following analytic detects `PutBucketLifecycle` events in AWS CloudTrail logs where a user sets a lifecycle rule for an S3 bucket with an expiration period of fewer than three days. This detection leverages CloudTrail logs to identify suspicious lifecycle configurations. This activity is significant because attackers may use it to delete CloudTrail logs quickly, thereby evading detection and impairing forensic investigations. If confirmed malicious, this could allow attackers to cover their tracks, making it difficult to trace their actions and respond to the breach effectively.
data_source:
    - ASL AWS CloudTrail
search: |-
    `amazon_security_lake` api.operation=PutBucketLifecycle
      | spath input=api.request.data path=LifecycleConfiguration.Rule.NoncurrentVersionExpiration.NoncurrentDays output=NoncurrentDays
      | where NoncurrentDays < 3
      | spath input=api.request.data
      | 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 NoncurrentDays
           bucketName
      | 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_putbucketlifecycle_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 it is a legitimate admin activity. Please consider filtering out these noisy events using userAgent, user_arn field names.
references:
    - https://stratus-red-team.cloud/attack-techniques/AWS/aws.defense-evasion.cloudtrail-lifecycle-rule/
tags:
    analytic_story:
        - AWS Defense Evasion
    asset_type: AWS Account
    mitre_attack_id:
        - T1485.001
        - T1562.008
    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/T1562.008/put_bucketlifecycle/asl_ocsf_cloudtrail.json
          sourcetype: aws:asl
          source: aws_asl