The rule identifies potential ransomware notes uploaded to AWS S3 buckets, leveraging the `PutObject` API call with common ransomware-related file extensions like `.ransom` and `.lock`. This behavior is detected in cases where misconfigured S3 buckets may be exploited to insert ransom notes, which adversaries use to extort victims. The rule includes a comprehensive description of investigation steps, false positive considerations, and response recommendations. It highlights the importance of verifying the identity of the actor performing the upload, analyzing request parameters, and checking the timing of actions to discern legitimate administrative activities from malicious uploads. Additionally, it suggests various proactive security measures such as auditing bucket permissions and enhancing monitoring capabilities to mitigate risk.