This rule is designed to detect potentially malicious activity in AWS Lambda functions by monitoring for updates to function configurations that involve attaching a Lambda layer. Such actions can indicate an adversary's attempt to inject malicious code into an existing function, which can allow them to utilize the function's IAM role for unauthorized AWS API calls. This rule specifically looks for events recorded in AWS CloudTrail, particularly those with the event source 'lambda.amazonaws.com' and actions related to configuration updates. The capability to update the function configuration is a common administrative task; however, when performed by unauthorized users or under suspicious circumstances, it could lead to privilege escalation and abuse of the Lambda service's permissions. Therefore, it is crucial to verify the legitimacy of such updates to identify potential security incidents.