M365 sign-ins from same account rotating across residential proxy IP/ASNs
Detects anomalous authentication patterns in Microsoft 365 logs characterized by rapid login attempts from a high number of distinct IP addresses and autonomous systems (ASNs) within a short timeframe. This behavior is indicative of Adversary-in-the-Middle (AiTM) attacks involving session-token theft and replay, where the adversary uses rotating residential proxy infrastructure to bypass location-based conditional access policies.
Microsoft Sentinel (KQL)
