This rule detects potentially malicious Kerberos Ticket Granting Ticket (TGT) requests that have pre-authentication disabled and utilize the RC4-HMAC encryption type. Specifically, it focuses on Event ID 4768 where the Pre-Authentication Type is set to 0. In an AS-REP Roasting attack, an attacker targets Kerberos accounts that do not require pre-authentication, allowing them to request an AS-REP message. By capturing this message, attackers can attempt to crack it offline, potentially exposing user passwords. The detection increases in significance when the TGT request is made for the ServiceName 'krbtgt' and uses the Ticket Encryption Type of '0x17', indicating a vulnerability to exploitation. It's essential for environments to monitor these requests as they can signify attempts to exploit weak authentication mechanisms within Active Directory.