Rule Library

Sigma Rules

174 rules found

3,731Total
3,132Detection
457Emerging
139Hunting
Emerging Threatcriticaltest

DarkSide Ransomware Pattern

Detects DarkSide Ransomware and helpers

WindowsProcess Creation
Florian Roth (Nextron Systems)Fri May 142021
Emerging Threatcriticaltest

FoggyWeb Backdoor DLL Loading

Detects DLL hijacking technique used by NOBELIUM in their FoggyWeb backdoor. Which loads a malicious version of the expected "version.dll" dll

WindowsImage Load (DLL)
Florian Roth (Nextron Systems)Mon Sep 272021
Emerging Threatcriticaltest

Goofy Guineapig Backdoor Service Creation

Detects service creation persistence used by the Goofy Guineapig backdoor

Windowssystem
Nasreddine Bencherchali (Nextron Systems)Mon May 152021
Emerging Threatcriticaltest

Moriya Rootkit File Created

Detects the creation of a file named "MoriyaStreamWatchmen.sys" in a specific location. This filename was reported to be related to the Moriya rootkit as described in the securelist's Operation TunnelSnake report.

WindowsFile Event
Bhabesh RajThu May 062021
Emerging Threatcriticaltest

Small Sieve Malware Potential C2 Communication

Detects potential C2 communication related to Small Sieve malware

Proxy Log
Nasreddine Bencherchali (Nextron Systems)Fri May 192021
Emerging Threatcriticaltest

HAFNIUM Exchange Exploitation Activity

Detects activity observed by different researchers to be HAFNIUM group activity (or related) on Exchange servers

WindowsProcess Creation
Florian Roth (Nextron Systems)Tue Mar 092021
Emerging Threatcriticaltest

REvil Kaseya Incident Malware Patterns

Detects process command line patterns and locations used by REvil group in Kaseya incident (can also match on other malware)

WindowsProcess Creation
Florian Roth (Nextron Systems)Sat Jul 032021
Emerging Threatcriticaltest

OWASSRF Exploitation Attempt Using Public POC - Proxy

Detects exploitation attempt of the OWASSRF variant targeting exchange servers using publicly available POC. It uses the OWA endpoint to access the powershell backend endpoint

Proxy Log
Nasreddine Bencherchali (Nextron Systems)Thu Dec 222022
Emerging Threatcriticaltest

OWASSRF Exploitation Attempt Using Public POC - Webserver

Detects exploitation attempt of the OWASSRF variant targeting exchange servers using publicly available POC. It uses the OWA endpoint to access the powershell backend endpoint

Web Server Log
Nasreddine Bencherchali (Nextron Systems)Thu Dec 222022
Emerging Threatcriticaltest

CVE-2023-23397 Exploitation Attempt

Detects outlook initiating connection to a WebDAV or SMB share, which could be a sign of CVE-2023-23397 exploitation.

Windowssecurity
Robert LeeThu Mar 162023
Emerging Threatcriticaltest

Potential CVE-2023-36884 Exploitation Pattern

Detects a unique pattern seen being used by RomCom potentially exploiting CVE-2023-36884

Proxy Log
X__JuniorWed Jul 122023
Emerging Threatcriticaltest

COLDSTEEL RAT Cleanup Command Execution

Detects the creation of a "rundll32" process from the ColdSteel persistence service to initiate the cleanup command by calling one of its own exports. This functionality is not present in "MileStone2017" and some "MileStone2016" samples

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Sun Apr 302023
Emerging Threatcriticaltest

COLDSTEEL RAT Service Persistence Execution

Detects the creation of an "svchost" process with specific command line flags, that were seen present and used by ColdSteel RAT

WindowsProcess Creation
X__Junior (Nextron Systems)Sun Apr 302023
Emerging Threatcriticaltest

Griffon Malware Attack Pattern

Detects process execution patterns related to Griffon malware as reported by Kaspersky

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Thu Mar 092023
Emerging Threatcriticaltest

Qakbot Rundll32 Exports Execution

Detects specific process tree behavior of a "rundll32" execution with exports linked with Qakbot activity.

WindowsProcess Creation
X__Junior (Nextron Systems)Wed May 242023
Emerging Threatcriticaltest

Qakbot Rundll32 Fake DLL Extension Execution

Detects specific process tree behavior of a "rundll32" execution where the DLL doesn't have the ".dll" extension. This is often linked with potential Qakbot activity.

WindowsProcess Creation
X__Junior (Nextron Systems)+1Wed May 242023
Emerging Threatcriticaltest

Rorschach Ransomware Execution Activity

Detects Rorschach ransomware execution activity

WindowsProcess Creation
X__Junior (Nextron Systems)Tue Apr 042023
Emerging Threatcriticaltest

SNAKE Malware Kernel Driver File Indicator

Detects SNAKE malware kernel driver file indicator

WindowsFile Event
Nasreddine Bencherchali (Nextron Systems)Wed May 102023
Emerging Threatcriticaltest

SNAKE Malware Service Persistence

Detects the creation of a service named "WerFaultSvc" which seems to be used by the SNAKE malware as a persistence mechanism as described by CISA in their report

Windowssystem
Nasreddine Bencherchali (Nextron Systems)Wed May 102023
Emerging Threatcriticaltest

Malicious DLL Load By Compromised 3CXDesktopApp

Detects DLL load activity of known compromised DLLs used in by the compromised 3CXDesktopApp

WindowsImage Load (DLL)
Nasreddine Bencherchali (Nextron Systems)Fri Mar 312023
Emerging Threatcriticaltest

Diamond Sleet APT Scheduled Task Creation

Detects registry event related to the creation of a scheduled task used by Diamond Sleet APT during exploitation of Team City CVE-2023-42793 vulnerability

Windowssecurity
Nasreddine Bencherchali (Nextron Systems)Tue Oct 242023
Emerging Threatcriticaltest

Mint Sandstorm - AsperaFaspex Suspicious Process Execution

Detects suspicious execution from AsperaFaspex as seen used by Mint Sandstorm

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)+1Thu Apr 202023
Emerging Threatcriticaltest

Mint Sandstorm - ManageEngine Suspicious Process Execution

Detects suspicious execution from ManageEngine as seen used by Mint Sandstorm

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)+1Thu Apr 202023
Emerging Threatcriticaltest

UNC4841 - Potential SEASPY Execution

Detects execution of specific named binaries which were used by UNC4841 to deploy their SEASPY backdoor

LinuxProcess Creation
Nasreddine Bencherchali (Nextron Systems)Fri Jun 162023
Emerging Threatcriticaltest

CVE-2024-1708 - ScreenConnect Path Traversal Exploitation - Security

This detects file modifications to ASPX and ASHX files within the root of the App_Extensions directory, which is allowed by a ZipSlip vulnerability in versions prior to 23.9.8. This occurs during exploitation of CVE-2024-1708. This requires an Advanced Auditing policy to log a successful Windows Event ID 4663 events and with a SACL set on the directory.

Windowssecurity
Matt Anderson+2Tue Feb 202024
Emerging Threatcriticaltest

CVE-2024-1709 - ScreenConnect Authentication Bypass Exploitation

Detects GET requests to '/SetupWizard.aspx/[anythinghere]' that indicate exploitation of the ScreenConnect vulnerability CVE-2024-1709.

Web Server Log
Matt Anderson+1Tue Feb 202024
Emerging Threatcriticalexperimental

Potential SharePoint ToolShell CVE-2025-53770 Exploitation - File Create

Detects the creation of file such as spinstall0.aspx which may indicate successful exploitation of CVE-2025-53770. CVE-2025-53770 is a zero-day vulnerability in SharePoint that allows remote code execution.

WindowsFile Event
Swachchhanda Shrawan Poudel (Nextron Systems)Mon Jul 212025
Emerging Threatcriticalexperimental

RedSun - TieringEngineService.exe Staged in RS-Prefixed Temp Dir

Detects the creation of a file named TieringEngineService.exe inside a directory whose path contains the RS- prefix characteristic of RedSun's staging directory (e.g. %TEMP%\RS-{GUID}\TieringEngineService.exe). RedSun registers a Cloud Files sync root under this RS-prefixed path and drops a masqueraded placeholder there as part of its oplock-based AV bypass and privilege escalation chain. The RS-{GUID} directory name is generated by RedSun itself and has no legitimate system usage, making the combination of this path prefix and the TieringEngineService.exe filename a highly specific indicator of RedSun activity.

WindowsFile Event
Swachchhanda Shrawan Poudel (Nextron Systems)Fri Apr 172026
Emerging Threatcriticalexperimental

RedSun - Named Pipe Created

Detects the creation of a named pipe with the hardcoded name "REDSUN". The RedSun exploit tool uses a pipe with this name for synchronisation and command communication between its components during the Cloud Files API + oplock-based AV bypass and privilege escalation chain. RedSun creates the pipe as \\??\pipe\REDSUN. The pipe server listens for the token-duplicated elevated process to connect and respond, completing the privilege escalation from user to SYSTEM. Presence of this pipe name indicates active or recent RedSun execution.

WindowsNamed Pipe Created
Swachchhanda Shrawan Poudel (Nextron Systems)Fri Apr 172026
Emerging Threatcriticalexperimental

RedSun - TieringEngineService.exe Detected as EICAR Test File

Detects Windows Defender (EventID 1119 - Remediation Action Failed) flagging TieringEngineService.exe dropped in a characteristic RS-{GUID} temporary directory, or the RedSun.exe process itself being present. This covers the staging pattern used by RedSun, a Cloud Files API and opportunistic lock (oplock) based AV bypass/privilege escalation tool. RedSun works as follows: 1. Registers a Cloud Files sync root and creates a Cloud Files placeholder for TieringEngineService.exe under %TEMP%\RS-{GUID}\ 2. The placeholder file carries EICAR test file content (Virus:DOS/EICAR_Test_File) to reliably trigger a Defender scan and remediation attempt 3. Requests a batch oplock (FSCTL_REQUEST_BATCH_OPLOCK) on the placeholder file 4. When Defender attempts to scan/quarantine the file, the oplock triggers - holding the file open 5. During the oplock break window, RedSun swaps the mount point (junction) to redirect \\?\C:\Windows\System32 to the attacker-controlled temp path 6. This races the AV/OS into executing the malicious TieringEngineService.exe with elevated privileges

Windowswindefend
Swachchhanda Shrawan Poudel (Nextron Systems)Fri Apr 172026