This rule detects the deletion of AWS Identity and Access Management (IAM) resource groups using AWS CloudTrail logs. The deletion of a resource group is a significant event as it can disrupt user management and may indicate potential malicious activity if performed by unauthorized entities. The rule operates by monitoring for successful DeleteGroup actions in CloudTrail, correlating them with specific IAM actions to identify and flag suspicious activities. The investigation guide provided with the rule suggests various steps for analyzing incidents of group deletion, points out potential false positives, and provides remediation steps to handle unauthorized deletions effectively. The overall objective is to ensure timely detection of potential threats to IAM configurations and maintain robust access control in AWS environments.