Sigma detection rules, expert-reviewed

Windows: Suspicious Attachment File Created in Outlook Temp Directories

Alerts on creation of risky file types in Outlook attachment temporary folders used during email attachment handling.

IIS Web Logs: SharePoint ToolPane and spinstall0.aspx CVE-2025-53770 Exploitation Indicators

Alerts on IIS log traffic to SharePoint ToolPane/spinstall0 endpoints with a SignOut referer, matching indicators for CVE-2025-53770 exploitation.

Windows Process Creation: Indicators of SharePoint spinstall0.aspx Encoded Command Exploitation (CVE-2025-53770)

Alerts on w3wp.exe command lines containing encoded spinstall0.aspx and SharePoint template layout path indicators consistent with CVE-2025-53770 exploitation.

Windows File Creation in SharePoint Web Server Extensions Suggesting ToolShell Drop

Alerts on Windows file creations within SharePoint Web Server Extensions that match suspicious spinstall/debug artifacts linked to CVE-2025-53770.

Windows: WinRAR/Rar.exe Writing Files to Startup Folder Locations

Alerts on WinRAR/Rar creating files under the Windows Startup folder, a common persistence attempt.

Windows Scheduled Task Creation via schtasks.exe Using sshd/ssh.exe for Tunnel Setup

Alerts when schtasks.exe creates scheduled tasks that invoke sshd.exe or ssh.exe with tunnel-related arguments.

Windows registry delete: remove ShellEx ContextMenuHandlers EPP key for "Scan with Defender"

Alerts when a registry key tied to the Defender “Scan with” context menu is deleted, excluding MsMpEng.exe activity.

Windows PowerShell sets Microsoft Defender threat severity default actions to Allow/NoAction

Alerts when PowerShell Set-MpPreference sets Defender threat-severity default actions to Allow or NoAction.

Windows reg.exe disables Defender WMI Autologger sessions by setting Start to 0

Flags reg.exe changing WMI Autologger Start for DefenderApiLogger/DefenderAuditLogger to 0, impairing ETW security logging.

Windows Process Execution: Remove Windows Defender Context Menu Registry Keys via reg.exe/PowerShell

Alerts on reg.exe/PowerShell deleting Defender context menu handler registry keys to remove right-click scanning.

Windows File Events: ADExplorer .dat Snapshot Written by ADExp.exe or ADExplorer.exe

Detects ADExplorer exporting an AD snapshot by writing .dat files on Windows.

Windows Registry Set: FileFix-style Command Evidence in TypedPaths url1

Flags Windows registry TypedPaths url1 updates containing URL fragments and command/script keywords consistent with FileFix behavior.

Windows Process Creation: HollowReaper.exe Execution for Process Hollowing

Flags execution of HollowReaper.exe, a process hollowing shellcode launcher associated with stealth payload execution.

Windows Doppelganger (Doppelanger.exe) LSASS Dump Tool Execution

Alerts on Windows execution of Doppelganger.exe with matching IMPHASH values associated with LSASS dumping.

Windows: Suspicious regsvr32 invocation by Notepad++ installer referencing NppShell.dll

Alerts when regsvr32 is run silently to register NppShell.dll but the regsvr32 image isn’t from standard Windows system locations.