The AWS IAM Failure Group Deletion detection rule identifies failed attempts to delete AWS Identity and Access Management (IAM) groups through AWS CloudTrail logs. This rule specifically looks for instances where the DeleteGroup API call fails with specific error codes, namely NoSuchEntityException (indicating that the group does not exist), DeleteConflictException (indicating that the group is involved in a conflict, such as having active users), and AccessDenied (indicating the user attempting the delete lacks sufficient privileges). Such failures can signal unauthorized attempts to interfere with IAM configurations, which could lead to potential privilege escalation or other malicious actions. This detection is crucial as unauthorized modifications may disrupt IAM policies, creating security risks that could expose sensitive resources to unauthorized access or denial of service within an AWS environment.