Sigma detection rules, expert-reviewed

PowerShell ScriptBlock Logging: Obfuscated RUNDLL Launcher using rundll32.exe and shell32.dll

Identifies PowerShell script content invoking rundll32.exe/shell32.dll via shellexec_rundll and referencing PowerShell.

Detect PowerShell COMPRESS OBFUSCATION using ASCII text encoding and stream/compression APIs

Flags PowerShell script blocks that combine ASCII encoding with Deflate/stream handling indicative of obfuscated payload compression.

PowerShell module activity launching rundll32 via shell32.dll obfuscation content

Alerts when PowerShell module payloads reference a shell32/rundll32 launcher pattern that includes PowerShell.

PowerShell Module Payload Obfuscation Using COMPRESS OBFUSCATION

Identifies PowerShell module payloads containing ASCII encoding and compression/stream obfuscation strings.

Windows System: Detect rundll32 Service Control Manager launches PowerShell via obfuscated parameters

Flags service creation where ImagePath uses rundll32/shell32 (shellexec_rundll) to invoke PowerShell.

Windows System: Service Control Manager PowerShell Obfuscation Using COMPRESS OBFUSCATION

Flags new Windows services whose ImagePath includes obfuscated PowerShell markers using COMPRESS/stream decompression.

Windows Security 4697: Obfuscated PowerShell via rundll32 shell32 shellexec_rundll

Alert on Security EID 4697 where service installation references rundll32/shell32.dll to launch PowerShell.

Windows Security 4697 PowerShell obfuscated content using COMPRESS OBFUSCATION components

Alerts on service creation events where the ServiceFileName includes PowerShell obfuscation patterns tied to compression stream and ASCII encoding.

Windows PowerShell Script Execution via Redirected Input Stream

Flags PowerShell/pwsh executions where the command line includes redirected input ("- <").

Windows Process Creation: Suspicious Microsoft Csi.exe or Rcsi.exe with C# Execution Capability

Alerts on Windows executions of Microsoft’s csi.exe/rcsi.exe that can be used to run C# code from command-line.

Windows WMIC loading JavaScript/VBScript engine libraries

Alerts on wmic.exe loading jscript.dll or vbscript.dll, a common sign of script execution via Windows Management Instrumentation.

Potential Windows Registry Persistence via AppCompatFlags TelemetryController Commands

Flags registry entries under TelemetryController\Command that reference executable/script payloads potentially abusing telemetry for persistence.

Windows sc.exe Security Descriptor Tampering to Deny Service Access via sdset

Alerts on sc.exe sdset commands that modify service security descriptors to deny access to critical trustees.

Windows Process: reg.exe Software Version Discovery via svcVersion Query

Alerts when reg.exe is used to query \Software\ for svcVersion, indicating Windows software version discovery.

Windows PowerShell Software Enumeration via Script Block Content

Flags PowerShell registry queries for installed software metadata combined with selection and table formatting.