Domain Admin/Administrator Account Reconnaissance
Detects reconnaissance activity involving attempts to enumerate domain administrator accounts and domain groups. Specifically, it looks for Event ID 4661 (An operation was performed on an object) with an AccessMask of '0x2d' (which indicates a read access attempt) on SAM_USER or SAM_GROUP objects whose ObjectName corresponds to well-known SIDs for the built-in Administrator account (-500) or Domain Admins group (-512) within a domain (S-1-5-21- prefix). This activity is often associated with adversaries using commands like 'net user administrator /domain' or 'net group domain admins /domain' to discover privileged accounts.
Sigma
