This detection rule identifies a scenario where an endpoint is making multiple authentication failures against 30 or more unique invalid domain users using the Kerberos protocol, as logged by Windows Event Log (specifically Event Code 4768). The focus is on indications of malicious activity, particularly a Password Spraying attack, where an attacker tries to authenticate against numerous accounts to gain unauthorized access or escalate privileges. The detection uses the failure code 0x6, which implies the specified user does not exist in the Kerberos database. Given that such behavior is not common in legitimate system operations, it could be indicative of an attack in progress. To implement this rule, organizations are advised to enable the relevant auditing policies to capture necessary event logs, and they are also provided with guidance on mitigating potential false positives, including conditions that may mimic attack behavior.