Rule Library

Sigma Rules

1,788 rules found for "Nextron Systems"

3,731Total
3,132Detection
457Emerging
139Hunting
Threat Huntlowtest

Potential Suspicious Execution From GUID Like Folder Names

Detects potential suspicious execution of a GUID like folder name located in a suspicious location such as %TEMP% as seen being used in IcedID attacks. Use this rule to hunt for potentially suspicious activity stemming from uncommon folders.

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Thu Sep 01windows
Threat Huntmediumtest

Execution From Webserver Root Folder

Detects a program executing from a web server root folder. Use this rule to hunt for potential interesting activity such as webshell or backdoors

WindowsProcess Creation
Florian Roth (Nextron Systems)Wed Jan 16windows
Threat Huntmediumtest

File or Folder Permissions Modifications

Detects a file or folder's permissions being modified or tampered with.

WindowsProcess Creation
Jakob Weinzettl+2Wed Oct 23windows
Threat Huntmediumtest

Use Short Name Path in Command Line

Detects the use of short name paths (8.3 format) in command lines, which can be used to obfuscate paths or access restricted locations. Windows creates short 8.3 filenames (like PROGRA~1) for compatibility with MS-DOS-based or 16-bit Windows programs. When investigating, examine: - Commands using short paths to access sensitive directories or files - Web servers on Windows (especially Apache) where short filenames could bypass security controls - Correlation with other suspicious behaviors - baseline of short name usage in your environment and look for deviations

WindowsProcess Creation
François Hubaut+1Sun Aug 07windows
Threat Huntlowtest

Process Terminated Via Taskkill

Detects execution of "taskkill.exe" in order to stop a service or a process. Look for suspicious parents executing this command in order to hunt for potential malicious activity. Attackers might leverage this in order to conduct data destruction or data encrypted for impact on the data stores of services like Exchange and SQL Server.

WindowsProcess Creation
François Hubaut+2Sun Dec 26windows
Threat Huntlowexperimental

Process Execution From WebDAV Share

Detects execution of processes with image paths starting with WebDAV shares (\\), which might indicate malicious file execution from remote web shares. Execution of processes from WebDAV shares can be a sign of lateral movement or exploitation attempts, especially if the process is not a known legitimate application. Exploitation Attempt of vulnerabilities like CVE-2025-33053 also involves executing processes from WebDAV paths.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Fri Jun 13windows
Threat Huntmediumtest

Arbitrary Command Execution Using WSL

Detects potential abuse of Windows Subsystem for Linux (WSL) binary as a Living of the Land binary in order to execute arbitrary Linux or Windows commands.

WindowsProcess Creation
oscd.community+2Mon Oct 05windows
Threat Huntmediumtest

Cab File Extraction Via Wusa.EXE

Detects execution of the "wusa.exe" (Windows Update Standalone Installer) utility to extract cab using the "/extract" argument that is no longer supported.

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Thu Aug 04windows
Threat Huntmediumtest

Microsoft Office Trusted Location Updated

Detects changes to the registry keys related to "Trusted Location" of Microsoft Office. Attackers might add additional trusted locations to avoid macro security restrictions.

WindowsRegistry Set
Nasreddine Bencherchali (Nextron Systems)Wed Jun 21windows
Threat Huntlowtest

Command Executed Via Run Dialog Box - Registry

Detects execution of commands via the run dialog box on Windows by checking values of the "RunMRU" registry key. This technique was seen being abused by threat actors to deceive users into pasting and executing malicious commands, often disguised as CAPTCHA verification steps.

WindowsRegistry Set
Ahmed Farouk+1Fri Nov 01windows
Threat Huntmediumtest

Service Binary in User Controlled Folder

Detects the setting of the "ImagePath" value of a service registry key to a path controlled by a non-administrator user such as "\AppData\" or "\ProgramData\". Attackers often use such directories for staging purposes. This rule might also trigger on badly written software, where if an attacker controls an auto starting service, they might achieve persistence or privilege escalation. Note that while ProgramData is a user controlled folder, software might apply strict ACLs which makes them only accessible to admin users. Remove such folders via filters if you experience a lot of noise.

WindowsRegistry Set
Nasreddine Bencherchali (Nextron Systems)+1Mon May 02windows
Threat Huntlowtest

Shell Context Menu Command Tampering

Detects changes to shell context menu commands. Use this rule to hunt for potential anomalies and suspicious shell commands.

WindowsRegistry Set
Nasreddine Bencherchali (Nextron Systems)Wed Mar 06windows