This rule is designed to detect suspicious activity related to the use of RC4 encryption in Kerberos service ticket requests. Specifically, it targets events where a Ticket Request (EventID 4769) occurs with certain criteria that indicate a potential security threat. The rule identifies requests where the TicketOptions field is set to `0x40810000` and the TicketEncryptionType field is set to `0x17`, which corresponds to RC4 encryption. The rule employs a reduction condition to filter out requests corresponding to service accounts whose names end with a dollar sign (`$`), effectively excluding common false positives associated with legitimate service accounts on legacy systems. In cases where service names do not meet this criterion, the rule will trigger, allowing organizations to investigate potential Kerberoasting attacks that leverage RC4 encryption, an older and less secure method of encryption. This detection is particularly pertinent in environments utilizing outdated Active Directory Functional Levels or legacy systems, as attackers often exploit these vulnerabilities to gain access to sensitive user credentials.