The Kubernetes Secret Access Denied detection rule monitors for unsuccessful attempts to access Kubernetes secrets, specifically tracking events such as 403 Forbidden errors and other unauthorized access messages. This monitoring is crucial as it provides insights into potentially malicious activities, such as enumeration or brute-force attacks on secrets by compromised accounts. The rule incorporates a deduplication period of 15 minutes, which resets upon each new failed access attempt. If there are 20 or more failed attempts to access secrets within this period, it should trigger an alert for further investigation. The severity of this detection is categorized as medium, reflecting the necessity to act swiftly when faced with multiple failed secret access attempts, as this may indicate serious security implications. The rule supports multiple cloud environments including Amazon EKS, Azure Kubernetes Service, and Google Kubernetes Engine, making it adaptable across platforms. The associated runbook provides a step-by-step guide on verifying failed access counts and identifying RBAC issues or malicious behaviors, along with a reference to Kubernetes documentation on secrets.