Sigma detection rules, expert-reviewed

Windows Security 4661 Detects Privileged AD User/Group SID Enumeration via SAM

Identifies SAM_USER/SAM_GROUP access events (4661) aimed at privileged SIDs or names containing 'admin' while ignoring computer accounts.

Windows Security 5136: Modify AD ACL for DCSync Extended Right via ntSecurityDescriptor

Flags directory ACL changes (EventID 5136) that include DCSync extended right GUIDs in ntSecurityDescriptor for DNS objects.

Windows Suspicious EXE in User Directory Launched by Microsoft Office Applications

Alert on Office spawning a .exe from C:\users\ (except when the child is Teams.exe).

Windows Security Logon Event ID 4800: Workstation Lock After Inactivity

Locked Workstation

Windows ADSI Schema Cache (.sch) File Creation by Uncommon Process

Alerts on .sch cache file creation in the Windows SchCache directory by uncommon executables.

Windows Security Event 5136: Suspicious LDAP attribute display names used

Alerts on Event 5136 containing specific LDAP display names indicative of LDAP-based data exchange.

Windows ETW Trace Evasion via Clearing/Disabling Logs or Providers

Identifies command-line attempts to clear/disable ETW traces or remove/modify ETW providers on Windows.

Windows: certutil.exe File Encoding to Base64 Using the -encode Flag

Alerts on Windows certutil.exe executions using -encode to base64-encode a file.

Windows Process Creation: Alert on Suspicious Parent of Core System Executables

Flags when core Windows executables (e.g., svchost, lsass, winlogon) are spawned by suspicious parent processes.

Windows mshta.exe Execution Using Non-HTA File Extensions

Alerts on mshta.exe launched with command-line indicators for suspicious non-HTA file types and VBScript.

Windows: RDP Session Startup Folder Backdoor via tsclient Share Targeting Startup Path

Flags mstsc.exe activity writing to the Windows Startup folder, indicating potential RDP session backdoor placement.

Windows svchost RDP via Reverse SSH Loopback Tunnel to 127.0.0.0/8:3389

Flags svchost.exe opening RDP (TCP 3389) connections to loopback, consistent with tunneled reverse access behavior.

Windows WFP Event 5156: RDP traffic via loopback when hosted by svchost termsvcs

Flags Windows EventID 5156 where svchost RDP (3389) traffic targets loopback addresses, suggesting tunneled local RDP usage.

Windows: Alert on suspicious parent process spawning csc.exe

Flags csc.exe execution when spawned by script/document hosts or PowerShell using encoded content, excluding common benign parent contexts.

Windows PowerShell Script Block Matches Common Reflection and Injection Keywords

Alerts on PowerShell script block text containing reflection, dynamic assembly loading, and injection-related keywords.