2026 Critical Enterprise Intrusion Chain Detection: On-Prem RDP or WinRM Logon from External Source Using Negotiate Auth
Detects interactive (Logon Type 10) or network (Logon Type 3) authentication to Windows hosts originating from external, non-RFC1918 IP addresses using 'Negotiate' authentication. This pattern is indicative of potential lateral movement from a cloud-connected environment into on-premises infrastructure, specifically where an adversary might be leveraging stolen session artifacts or credentials to bypass standard Kerberos-based domain authentication.
Sigma
