ProxyShell/ProxyLogon: Exchange w3wp.exe Spawns Shell or Drops ASPX

Detects anomalous child process execution (e.g., cmd.exe, powershell.exe) by the Microsoft Exchange IIS worker process (w3wp.exe) or the creation of .aspx files in Exchange web directories. This behavior is highly indicative of post-exploitation activity, such as web shell deployment, frequently observed in attacks targeting vulnerabilities like ProxyShell and ProxyLogon.

Microsoft Sentinel (KQL)