Spike in Kerberos Revoked Credentials Errors

Before an attacker can access critical services, they must first acquire valid credentials. Kerberos is an authentication protocol that verifies user credentials and permissions for accessing services. When a user wants to access a service, they submit credentials to an authentication server, which then provides a ticket (essentially a cryptographic proof of identity). An attacker can attempt to gain a valid Kerberos ticket with a brute force attack. A brute force attack is a method for guessing a weak user or system password in the initial authentication request. Brute force attacks can occur manually through trial and error or with password cracking tools.