This detection rule, developed by Elastic, is designed to identify an unusually high number of failed attempts to assume an AWS Identity and Access Management (IAM) role, which could indicate a brute-force attack. IAM roles provide temporary security credentials and are usually assumed by trusted users or services, making them a potential target for adversaries aiming to gain unauthorized access to AWS resources. The rule leverages AWS-specific cloud trail logs to monitor actions that involve policies related to assuming roles. If an attacker attempts to enumerate IAM roles by triggering failure events, the rule captures such instances based on the frequency of exceptions logged, specifically looking for 'MalformedPolicyDocumentException'. In cases of detection, the rule suggests various investigative steps to confirm the legitimacy of the actions, assess the damage, and respond appropriately. Overall, this rule plays a crucial role in enhancing cloud security by detecting potentially malicious activities related to IAM roles.