AWS Defense Evasion PutBucketLifecycle

SPLUNK detection rule by Bhavin Patel · Apache-2.0

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.

name: AWS Defense Evasion PutBucketLifecycle
id: ce1c0e2b-9303-4903-818b-0d9002fc6ea4
version: 10
creation_date: '2022-07-25'
modification_date: '2026-05-13'
author: Bhavin Patel
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:
    - AWS CloudTrail PutBucketLifecycle
search: |-
    `cloudtrail` eventName=PutBucketLifecycle user_type=IAMUser errorCode=success
      | spath path=requestParameters{}.LifecycleConfiguration{}.Rule{}.Expiration{}.Days output=expiration_days
      | spath path=requestParameters{}.bucketName output=bucket_name
      | rename user_name as user
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY signature dest user
           user_agent src vendor_account
           vendor_region vendor_product bucket_name
           expiration_days
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `aws_defense_evasion_putbucketlifecycle_filter`
how_to_implement: You must install Splunk AWS Add on and enable CloudTrail logs in your AWS Environment. We recommend our users to set the expiration days value according to your company's log retention policies.
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/
analytic_story:
    - AWS Defense Evasion
asset_type: AWS Account
mitre_attack_id:
    - T1485.001
    - 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/put_bucketlifecycle/aws_cloudtrail_events.json
          sourcetype: aws:cloudtrail
          source: aws_cloudtrail
      test_type: unit

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