The AWS EC2 Download Instance User Data rule monitors access to EC2 instance user data, specifically tracking when an entity downloads user data scripts from multiple EC2 instances. This action could indicate attempts to extract sensitive information, potentially including unsecured credentials. The rule is triggered when there are five or more accesses to EC2 user data, reflecting a possible reconnaissance or discovery phase by malicious actors. By utilizing AWS CloudTrail logs, the detection mechanism is designed to highlight unexpected or unauthorized access behaviors and log the relevant event details for further investigation. Users are advised to ensure that EC2 instances do not have sensitive credentials or other critical information stored in user data scripts.