Microsoft SharePoint Possible ASPX/ASP Web Shell Activity

Adair Collins@ajc

•updated Jul 21, 2025•12•6•13,654

This rule detects the creation or modification of ASPX/ASP files within specific SharePoint web server directories on devices identified as vulnerable to CVE-2025-49706 or CVE-2025-53770. It leverages vulnerability management data to narrow down the scope to only vulnerable SharePoint servers, then monitors file events in common SharePoint LAYOUTS paths for web shell indicators. The rule also uses file profiling to identify potentially novel or malicious ASPX/ASP files that lack Defender visibility.