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ASL AWS Defense Evasion PutBucketLifecycle

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.

View Source

Detection Logic

`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`

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.

Field Validations

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