This analytic rule detects when an Amazon EC2 snapshot is shared externally with a different AWS account. By analyzing AWS CloudTrail events related to the modification of snapshot attributes, it identifies when the permission to share a snapshot is granted to an account outside of the original account's control. Such modifications can be indicative of potential data exfiltration attempts as unauthorized parties could access sensitive data contained in the snapshots. The detection rule focuses on logs generated by CloudTrail, particularly monitoring for changes that do not match the originating AWS account, thereby flagging any unauthorized sharing activity which could lead to data breaches or exploitation of sensitive information.