That’s when Detective Controls earn their name. They don’t stop the fire—they tell you exactly where it’s burning, how fast, and why. In a Kerberos authentication environment, speed and accuracy matter. Tickets expire. Clocks drift. Replay attacks hide in the noise. Without clear visibility, you lose the timeline, and the timeline is everything.
Detective Controls for Kerberos focus on observing, logging, and alerting in real time. They track authentication requests, look for anomalies in tickets, and flag failed exchanges before they spiral. Think of AS-REQ and TGS-REQ patterns that deviate from normal baselines. Think of service tickets that show up where they never should. Think of clock skew that breaks trust between domain controllers and clients. These signals tell you where to act.
The essentials: capture and store Kerberos logs from key distribution centers, monitor for failed logins by user, host, and service, and trigger alerts on suspicious patterns. Pay close attention to ticket lifetimes and renewals—an unusual renewal can mean persistence by an attacker. Combine source IP analysis with service principal mapping to detect lateral movement attempts.