The 'Decoy Secret Accessed' rule is a high-severity detection rule designed to monitor access to a decoy secret in AWS Secrets Manager, specifically identifying when an actor accesses a private decoy secret. This rule operates by analyzing AWS API call actions related to the 'Decrypt' operation of the AWS Key Management Service (KMS) and aims to spot unusual behavior flagged as potentially unauthorized access. The rule will become triggered when access is detected on the specified secret, indicating a required investigation or response due to the intended use of the decoy secret in monitoring abnormal activities. The rule is presently disabled but contributes to an analytical framework focusing on security posture by leveraging decoy resources to detect and respond to potential threats in AWS environments.