The rule detects when an AWS storage snapshot has been made public, potentially leading to unauthorized access and data exfiltration. This is accomplished by monitoring AWS CloudTrail logs for events related to snapshot permission modifications. The primary event of interest is the 'ModifySnapshotAttribute' API call, specifically when the 'CREATE_VOLUME_PERMISSION' attribute is altered to include 'all' users. The rule is set to medium severity, indicating a significant but not critical risk, and aims to alert administrators to adjust the snapshot configuration promptly to mitigate exposure risk. Adequate logging of relevant attributes such as user agent, source IP address, recipient account ID, and any AWS resource ARNs is incorporated to facilitate investigation and response actions.