Sigma detection rules, expert-reviewed

Windows Registry Set to Disable Windows Defender Components

Flags registry changes that turn off Windows Defender protections via Defender and Security Center policy keys.

Windows Registry: Attachment Manager policy tampering via Attachments settings values

Detects registry changes to Windows Attachment Manager policy values that can disable or alter download safety controls.

Windows Registry Tampering: Attachment Manager Associations Default File Type Risk and LowRiskFileTypes

Flags Windows registry changes to Attachment Manager associations that set DefaultFileTypeRisk and modify LowRiskFileTypes.

Windows Registry Change Disabling WinDefend Service (WinDefend Start=4)

Flags registry changes that set WinDefend service Start to 0x4, indicating potential defensive impairment.

Windows Registry AutoLogger Session Disable/Start Tampering via Event Log Targets

Alerts when registry changes disable or stop AutoLogger sessions for EventLog-* or Defender by setting Enabled/Start to 0x0.

Windows sc.exe Service StartupType Change to Disabled or Demand

Flags sc.exe commands that change a Windows service startup type to disabled or demand.

Windows reg.exe importing .reg files from common user and temp directories

Flags reg.exe importing .reg files when the command line references user or temp directories.

Windows reg.exe deletes service registry keys using the delete flag

Alerts on reg.exe command lines that delete entries under the Windows services registry path.

Windows query.exe used to enumerate sessions and processes (possible data exfil staging)

Detects query.exe runs that request session and process output, matching patterns consistent with staged data collection.

Windows Defender mpclient.dll Side-loading: MpCmdRun.exe or NisSrv.exe from Non-Default Paths

Alerts when MpCmdRun.exe or NisSrv.exe runs from non-default directories, a common indicator of possible mpclient.dll sideloading.

Windows dnscmd.exe DNS Zone and Record Enumeration Command Execution

Flags dnscmd.exe executions that enumerate DNS zones/records via process creation command-line parameters.

Windows ISO File Creation in User Temp and Outlook Cache Folders

Alerts on creation of .iso files in Windows AppData temp or Outlook cache paths.

Windows DLL Search Order Hijack via Space in System Directory Paths

Alerts on .dll events targeting Windows system paths with an extra space, indicative of DLL search order hijacking.

Windows Sysmon Driver Altitude Registry Changes

Identifies registry writes that change the Sysmon instance altitude value, which can disrupt Sysmon loading at boot.

Windows schtasks Scheduled Task Create/Modify Running as SYSTEM

Alerts on Windows schtasks task create/modify commands that set the run account to NT AUTHORITY\SYSTEM.