LoFP / bucket components may be deleted by a system or network administrator. verify whether the user identity, user agent, and/or hostname should be making changes in your environment. bucket component deletions by unfamiliar users or hosts should be investigated. if known behavior is causing false positives, it can be exempted from the rule.

event.dataset:aws.cloudtrail and event.provider:s3.amazonaws.com and
  event.action:(DeleteBucketPolicy or DeleteBucketReplication or DeleteBucketCors or
                DeleteBucketEncryption or DeleteBucketLifecycle)
  and event.outcome:success