The rule 'AWS.S3.BucketDeleted' is designed to detect the deletion of Amazon S3 buckets, including related policies and websites. When an S3 bucket is deleted, it generates a log entry in AWS CloudTrail under the event name 'DeleteBucket'. This detection rule is critical for monitoring potential data destruction events as the deletion of a bucket can lead to significant data loss if not intended. The rule uses specific attributes, including 'sourceIpAddress', 'userAgent', 'recipientAccountId', and 'vpcEndpointId', to provide context about the deletion event, helping security teams assess whether the action was legitimate or malicious. The rule encompasses various test cases to ensure the appropriate logging is captured for successful and failed deletion attempts, highlighting cases where users may attempt to delete non-empty buckets, which would generate an error 'BucketNotEmpty'. Furthermore, this rule is tagged with a low severity level of 'Info', indicating that the event alone does not necessarily indicate a breach but requires further investigation. The overall intent is to monitor AWS S3 activity effectively, providing a safeguard for data integrity.