This analytic rule is designed to identify legitimate Domain Controller (DC) promotion events by monitoring Windows Security Event Code 4742. When a computer assigns itself Service Principal Names (SPNs) necessary for DC functionality, it indicates a promotion event. The detection of this activity is critical for identifying unauthorized additions of rogue DCs to the network, which could signify a DCShadow attack. Such attacks allow adversaries to manipulate Active Directory, posing grave risks of privilege escalation and persistent access in the environment. By utilizing event logs, the rule detects these pivotal changes within the AD infrastructure and helps safeguard against potential threats and exploits that compromise the integrity of the domain controller architecture, making it essential for proactive security measures.