Rule Library

Sigma Rules

294 rules found

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

BaaUpdate.exe Suspicious DLL Load

Detects BitLocker Access Agent Update Utility (baaupdate.exe) loading DLLs from suspicious locations that are publicly writable which could indicate an attempt to lateral movement via BitLocker DCOM & COM Hijacking. This technique abuses COM Classes configured as INTERACTIVE USER to spawn processes in the context of the logged-on user's session. Specifically, it targets the BDEUILauncher Class (CLSID ab93b6f1-be76-4185-a488-a9001b105b94) which can launch BaaUpdate.exe, which is vulnerable to COM Hijacking when started with input parameters. This allows attackers to execute code in the user's context without needing to steal credentials or use additional techniques to compromise the account.

WindowsImage Load (DLL)
Swachchhanda Shrawan Poudel (Nextron Systems)Sat Oct 18windows
Detectionmediumexperimental

MMC Loading Script Engines DLLs

Detects when the Microsoft Management Console (MMC) loads the DLL libraries like vbscript, jscript etc which might indicate an attempt to execute malicious scripts within a trusted system process for bypassing application whitelisting or defense evasion.

WindowsImage Load (DLL)
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Feb 05windows
Detectionhighexperimental

Suspicious Loading of Dbgcore/Dbghelp DLLs from Uncommon Location

Detects loading of dbgcore.dll or dbghelp.dll from uncommon locations such as user directories. These DLLs contain the MiniDumpWriteDump function, which can be abused for credential dumping purposes or in some cases for evading EDR/AV detection by suspending processes.

WindowsImage Load (DLL)
Swachchhanda Shrawan Poudel (Nextron Systems)Thu Nov 27windows
Detectionhighexperimental

Trusted Path Bypass via Windows Directory Spoofing

Detects DLLs loading from a spoofed Windows directory path with an extra space (e.g "C:\Windows \System32") which can bypass Windows trusted path verification. This technique tricks Windows into treating the path as trusted, allowing malicious DLLs to load with high integrity privileges bypassing UAC.

WindowsImage Load (DLL)
Swachchhanda Shrawan Poudel (Nextron Systems)Tue Jun 17windows
Detectionmediumexperimental

Suspicious Non-Browser Network Communication With Google API

Detects a non-browser process interacting with the Google API which could indicate the use of a covert C2 such as Google Sheet C2 (GC2-sheet)

WindowsNetwork Connection
Gavin KnappMon May 01windows
Detectionhighexperimental

Network Connection Initiated via Finger.EXE

Detects network connections via finger.exe, which can be abused by threat actors to retrieve remote commands for execution on Windows devices. In one ClickFix malware campaign, adversaries leveraged the finger protocol to fetch commands from a remote server. Since the finger utility is not commonly used in modern Windows environments, its presence already raises suspicion. Investigating such network connections can also help identify potential malicious infrastructure used by threat actors

WindowsNetwork Connection
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Nov 19windows
Detectionmediumexperimental

Remote Access Tool - AnyDesk Incoming Connection

Detects incoming connections to AnyDesk. This could indicate a potential remote attacker trying to connect to a listening instance of AnyDesk and use it as potential command and control channel.

WindowsNetwork Connection
Mon Sep 02windows
Detectionmediumexperimental

DMSA Service Account Created in Specific OUs - PowerShell

Detects the creation of a dMSA service account using the New-ADServiceAccount cmdlet in certain OUs. The fact that the cmdlet is used to create a dMSASvc account in a specific OU is highly suspicious. It is a pattern trying to exploit the BadSuccessor privilege escalation vulnerability in Windows Server 2025. On top of that, if the user that is creating the dMSASvc account is not a legitimate administrator or does not have the necessary permissions, it is a strong signal of an attempted or successful abuse of the BaDSuccessor vulnerability for privilege escalation within the Windows Server 2025 Active Directory environment.

WindowsPowerShell Script
Swachchhanda Shrawan Poudel (Nextron Systems)Sat May 24windows
Detectionlowexperimental

DMSA Link Attributes Modified

Detects modification of dMSA link attributes (msDS-ManagedAccountPrecededByLink) via PowerShell scripts. This command line pattern could be an indicator an attempt to exploit the BadSuccessor privilege escalation vulnerability in Windows Server 2025.

WindowsPowerShell Script
Swachchhanda Shrawan Poudel (Nextron Systems)Sat May 24windows
Detectionmediumexperimental

Potential Unconstrained Delegation Discovery Via Get-ADComputer - ScriptBlock

Detects the use of the "Get-ADComputer" cmdlet in order to identify systems which are configured for unconstrained delegation.

WindowsPowerShell Script
François HubautWed Mar 05windows
Detectionmediumexperimental

Registry Modification Attempt Via VBScript - PowerShell

Detects attempts to modify the registry using VBScript's CreateObject("Wscript.shell") and RegWrite methods embedded within PowerShell scripts or commands. Threat actors commonly embed VBScript code within PowerShell to perform registry modifications, attempting to evade detection that monitors for direct registry access through traditional tools. This technique can be used for persistence, defense evasion, and privilege escalation by modifying registry keys without using regedit.exe, reg.exe, or PowerShell's native registry cmdlets.

WindowsPowerShell Script
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Aug 13windows
Detectionhighexperimental

Suspicious Process Access to LSASS with Dbgcore/Dbghelp DLLs

Detects suspicious process access to LSASS.exe from processes located in uncommon locations with dbgcore.dll or dbghelp.dll in the call trace. These DLLs contain functions like MiniDumpWriteDump that can be abused for credential dumping purposes. While modern tools like Mimikatz have moved to using ntdll.dll, dbgcore.dll and dbghelp.dll are still used by basic credential dumping utilities and legacy tools for LSASS memory access and process suspension techniques.

WindowsProcess Access
Swachchhanda Shrawan Poudel (Nextron Systems)Thu Nov 27windows
Detectionhighexperimental

Suspicious Process Access of MsMpEng by WerFaultSecure - EDR-Freeze

Detects process access events where WerFaultSecure accesses MsMpEng.exe with dbgcore.dll or dbghelp.dll in the call trace, indicating potential EDR freeze techniques. This technique leverages WerFaultSecure.exe running as a Protected Process Light (PPL) with WinTCB protection level to call MiniDumpWriteDump and suspend EDR/AV processes, allowing malicious activity to execute undetected during the suspension period.

WindowsProcess Access
Swachchhanda Shrawan Poudel (Nextron Systems)Thu Nov 27windows
Detectionhighexperimental

Windows AMSI Related Registry Tampering Via CommandLine

Detects tampering of AMSI (Anti-Malware Scan Interface) related registry values via command line tools such as reg.exe or PowerShell. AMSI provides a generic interface for applications and services to integrate with antimalware products. Adversaries may disable AMSI to evade detection of malicious scripts and code execution.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Thu Dec 25windows
Detectionhighexperimental

Suspicious ArcSOC.exe Child Process

Detects script interpreters, command-line tools, and similar suspicious child processes of ArcSOC.exe. ArcSOC.exe is the process name which hosts ArcGIS Server REST services. If an attacker compromises an ArcGIS Server system and uploads a malicious Server Object Extension (SOE), they can send crafted requests to the corresponding service endpoint and remotely execute code from the ArcSOC.exe process.

WindowsProcess Creation
Micah BabinskiTue Nov 25windows
Detectionhighexperimental

Windows EventLog Autologger Session Registry Modification Via CommandLine

Detects attempts to disable Windows EventLog autologger sessions via registry modification. The AutoLogger event tracing session records events that occur early in the operating system boot process. Applications and device drivers can use the AutoLogger session to capture traces before the user logs in. Adversaries may disable these sessions to evade detection and prevent security monitoring of early boot activities and system events.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Thu Dec 25windows
Detectionhighexperimental

Suspicious Autorun Registry Modified via WMI

Detects suspicious activity where the WMIC process is used to create an autorun registry entry via reg.exe, which is often indicative of persistence mechanisms employed by malware.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Mon Feb 17windows
Detectionhighexperimental

Suspicious BitLocker Access Agent Update Utility Execution

Detects the execution of the BitLocker Access Agent Update Utility (baaupdate.exe) which is not a common parent process for other processes. Suspicious child processes spawned by baaupdate.exe could indicate an attempt at lateral movement via BitLocker DCOM & COM Hijacking.

WindowsProcess Creation
andrewdanis+1Sat Oct 18windows
Detectionhighexperimental

Suspicious CertReq Command to Download

Detects a suspicious CertReq execution downloading a file. This behavior is often used by attackers to download additional payloads or configuration files. Certreq is a built-in Windows utility used to request and retrieve certificates from a certification authority (CA). However, it can be abused by threat actors for malicious purposes.

WindowsProcess Creation
Christian Burkard (Nextron Systems)Wed Nov 24windows
Detectionmediumexperimental

Cmd Launched with Hidden Start Flags to Suspicious Targets

Detects cmd.exe executing commands with the "start" utility using "/b" (no window) or "/min" (minimized) flags. To reduce false positives from standard background tasks, detection is restricted to scenarios where the target is a known script extension or located in suspicious temporary/public directories. This technique was observed in Chaos, DarkSide, and Emotet malware campaigns.

WindowsProcess Creation
Vladan Sekulic+1Sat Jan 24windows
Detectionmediumexperimental

OpenEDR Spawning Command Shell

Detects the OpenEDR ssh-shellhost.exe spawning a command shell (cmd.exe) or PowerShell with PTY (pseudo-terminal) capabilities. This may indicate remote command execution through OpenEDR's remote management features, which could be legitimate administrative activity or potential abuse of the remote access tool. Threat actors may leverage OpenEDR's remote shell capabilities to execute commands on compromised systems, facilitating lateral movement or other command-and-control operations.

WindowsProcess Creation
kostastsaleThu Feb 19windows
Detectionhighexperimental

Potentially Suspicious Child Processes Spawned by ConHost

Detects suspicious child processes related to Windows Shell utilities spawned by `conhost.exe`, which could indicate malicious activity using trusted system components.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Feb 05windows
Detectionmediumexperimental

New DMSA Service Account Created in Specific OUs

Detects the creation of a dMSASvc account using the New-ADServiceAccount cmdlet in certain OUs. The fact that the Cmdlet is used to create a dMSASvc account in a specific OU is highly suspicious. It is a pattern trying to exploit the BadSuccessor privilege escalation vulnerability in Windows Server 2025. On top of that, if the user that is creating the dMSASvc account is not a legitimate administrator or does not have the necessary permissions, it is a strong signal of an attempted or successful abuse of the BaDSuccessor vulnerability for privilege escalation within the Windows Server 2025 Active Directory environment.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Sat May 24windows
Detectionhighexperimental

Windows Credential Guard Registry Tampering Via CommandLine

Detects attempts to add, modify, or delete Windows Credential Guard related registry keys or values via command line tools such as Reg.exe or PowerShell. Credential Guard uses virtualization-based security to isolate secrets so that only privileged system software can access them. Adversaries may disable Credential Guard to gain access to sensitive credentials stored in the system, such as NTLM hashes and Kerberos tickets, which can be used for lateral movement and privilege escalation. The rule matches suspicious command lines that target DeviceGuard or LSA registry paths and manipulate keys like EnableVirtualizationBasedSecurity, RequirePlatformSecurityFeatures, or LsaCfgFlags. Such activity may indicate an attempt to disable or tamper with Credential Guard, potentially exposing sensitive credentials for misuse.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Fri Dec 26windows
Detectionhighexperimental

PowerShell Defender Threat Severity Default Action Set to 'Allow' or 'NoAction'

Detects the use of PowerShell to execute the 'Set-MpPreference' cmdlet to configure Windows Defender's threat severity default action to 'Allow' (value '6') or 'NoAction' (value '9'). This is a highly suspicious configuration change that effectively disables Defender's ability to automatically mitigate threats of a certain severity level. An attacker might use this technique via the command line to bypass defenses before executing payloads.

WindowsProcess Creation
Matt Anderson (Huntress)Fri Jul 11windows
Detectionhighexperimental

Windows Defender Context Menu Removed

Detects the use of reg.exe or PowerShell to delete the Windows Defender context menu handler registry keys. This action removes the "Scan with Microsoft Defender" option from the right-click menu for files, directories, and drives. Attackers may use this technique to hinder manual, on-demand scans and reduce the visibility of the security product.

WindowsProcess Creation
Matt Anderson (Huntress)Wed Jul 09windows
Detectionhighexperimental

Devcon Execution Disabling VMware VMCI Device

Detects execution of devcon.exe with commands that disable the VMware Virtual Machine Communication Interface (VMCI) device. This can be legitimate during VMware Tools troubleshooting or driver conflicts, but may also indicate malware attempting to hijack communication with the hardware via the VMCI device. This has been used to facilitate VMware ESXi vulnerability exploits to escape VMs and execute code on the ESXi host.

WindowsProcess Creation
Matt Anderson+2Fri Jan 02windows
Detectionlowexperimental

System Information Discovery via Registry Queries

Detects attempts to query system information directly from the Windows Registry.

WindowsProcess Creation
lazargThu Jun 12windows
Detectionhighexperimental

Security Event Logging Disabled via MiniNt Registry Key - Process

Detects attempts to disable security event logging by adding the `MiniNt` registry key. This key is used to disable the Windows Event Log service, which collects and stores event logs from the operating system and applications. Adversaries may want to disable this service to prevent logging of security events that could be used to detect their activities.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Apr 09windows
Detectionhighexperimental

Suspicious Child Process of Notepad++ Updater - GUP.Exe

Detects suspicious child process creation by the Notepad++ updater process (gup.exe). This could indicate potential exploitation of the updater component to deliver unwanted malware.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Tue Feb 03windows
Detectionhighexperimental

HackTool - Doppelanger LSASS Dumper Execution

Detects the execution of the Doppelanger hacktool which is used to dump LSASS memory via process cloning while evading common detection methods

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Tue Jul 01windows
Detectionhighexperimental

Hacktool - EDR-Freeze Execution

Detects execution of EDR-Freeze, a tool that exploits the MiniDumpWriteDump function and WerFaultSecure.exe to suspend EDR and Antivirus processes on Windows. EDR-Freeze leverages a race-condition attack to put security processes into a dormant state by suspending WerFaultSecure at the moment it freezes the target process. This technique does not require kernel-level exploits or BYOVD, but instead abuses user-mode functionality to temporarily disable monitoring by EDR or Antimalware solutions.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Sep 24windows
Detectionhighexperimental

HackTool - HollowReaper Execution

Detects usage of HollowReaper, a process hollowing shellcode launcher used for stealth payload execution through process hollowing. It replaces the memory of a legitimate process with custom shellcode, allowing the attacker to execute payloads under the guise of trusted binaries.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Tue Jul 01windows
Detectionmediumexperimental

HackTool - LaZagne Execution

Detects the execution of the LaZagne. A utility used to retrieve multiple types of passwords stored on a local computer. LaZagne has been leveraged multiple times by threat actors in order to dump credentials.

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)+1Mon Jun 24windows
Detectionhighexperimental

HackTool - NetExec Execution

Detects execution of the hacktool NetExec. NetExec (formerly CrackMapExec) is a widely used post-exploitation tool designed for Active Directory penetration testing and network enumeration In enterprise environments, the use of NetExec is considered suspicious or potentially malicious because it enables attackers to enumerate hosts, exploit network services, and move laterally across systems. Threat actors and red teams commonly use NetExec to identify vulnerable systems, harvest credentials, and execute commands remotely.

WindowsProcess Creation
Chirag DamaniSun Mar 29windows
Detectionhighexperimental

HKTL - SharpSuccessor Privilege Escalation Tool Execution

Detects the execution of SharpSuccessor, a tool used to exploit the BadSuccessor attack for privilege escalation in WinServer 2025 Active Directory environments. Successful usage of this tool can let the attackers gain the domain admin privileges by exploiting the BadSuccessor vulnerability.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Fri Jun 06windows
Detectionhighexperimental

HackTool - WSASS Execution

Detects execution of WSASS, a tool used to dump LSASS memory on Windows systems by leveraging WER's (Windows Error Reporting) WerFaultSecure.EXE to bypass PPL (Protected Process Light) protections.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Sun Nov 23windows
Detectionhighexperimental

Hypervisor-protected Code Integrity (HVCI) Related Registry Tampering Via CommandLine

Detects the tampering of Hypervisor-protected Code Integrity (HVCI) related registry values via command line tool reg.exe. HVCI uses virtualization-based security to protect code integrity by ensuring that only trusted code can run in kernel mode. Adversaries may tamper with HVCI to load malicious or unsigned drivers, which can be used to escalate privileges, maintain persistence, or evade security mechanisms.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Mon Jan 26windows
Detectionmediumexperimental

IIS WebServer Log Deletion via CommandLine Utilities

Detects attempts to delete Internet Information Services (IIS) log files via command line utilities, which is a common defense evasion technique used by attackers to cover their tracks. Threat actors often abuse vulnerabilities in web applications hosted on IIS servers to gain initial access and later delete IIS logs to evade detection.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Tue Sep 02windows
Detectionhighexperimental

Attempts of Kerberos Coercion Via DNS SPN Spoofing

Detects the presence of "UWhRC....AAYBAAAA" pattern in command line. The pattern "1UWhRCAAAAA..BAAAA" is a base64-encoded signature that corresponds to a marshaled CREDENTIAL_TARGET_INFORMATION structure. Attackers can use this technique to coerce authentication from victim systems to attacker-controlled hosts. It is one of the strong indicators of a Kerberos coercion attack, where adversaries manipulate DNS records to spoof Service Principal Names (SPNs) and redirect authentication requests like in CVE-2025-33073. If you see this pattern in the command line, it is likely an attempt to add spoofed Service Principal Names (SPNs) to DNS records, or checking for the presence of such records through the `nslookup` command.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Fri Jun 20windows
Detectionmediumexperimental

Windows Default Domain GPO Modification via GPME

Detects the use of the Group Policy Management Editor (GPME) to modify Default Domain or Default Domain Controllers Group Policy Objects (GPOs). Adversaries may leverage GPME to make stealthy changes in these default GPOs to deploy malicious GPOs configurations across the domain without raising suspicion.

WindowsProcess Creation
TropChaudSat Nov 22windows
Detectionhighexperimental

MMC Executing Files with Reversed Extensions Using RTLO Abuse

Detects malicious behavior where the MMC utility (`mmc.exe`) executes files with reversed extensions caused by Right-to-Left Override (RLO) abuse, disguising them as document formats.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Feb 05windows
Detectionlowexperimental

Windows MSIX Package Support Framework AI_STUBS Execution

Detects execution of Advanced Installer MSIX Package Support Framework (PSF) components, specifically AI_STUBS executables with original filename 'popupwrapper.exe'. This activity may indicate malicious MSIX packages build with Advanced Installer leveraging the Package Support Framework to bypass application control restrictions.

WindowsProcess Creation
Michael Haag+1Mon Nov 03windows
Detectionlowexperimental

Notepad Password Files Discovery

Detects the execution of Notepad to open a file that has the string "password" which may indicate unauthorized access to credentials or suspicious activity.

WindowsProcess Creation
The DFIR ReportFri Feb 21windows
Detectionhighexperimental

Obfuscated PowerShell MSI Install via WindowsInstaller COM

Detects the execution of obfuscated PowerShell commands that attempt to install MSI packages via the Windows Installer COM object (`WindowsInstaller.Installer`). The technique involves manipulating strings to hide functionality, such as constructing class names using string insertion (e.g., 'indowsInstaller.Installer'.Insert(0,'W')) and correcting malformed URLs (e.g., converting 'htps://' to 'https://') at runtime. This behavior is commonly associated with malware loaders or droppers that aim to bypass static detection by hiding intent in runtime-generated strings and using legitimate tools for code execution. The use of `InstallProduct` and COM object creation, particularly combined with hidden window execution and suppressed UI, indicates an attempt to install software (likely malicious) without user interaction.

WindowsProcess Creation
Meroujan Antonyan (vx3r)Tue May 27windows
Detectionmediumexperimental

PowerShell MSI Install via WindowsInstaller COM From Remote Location

Detects the execution of PowerShell commands that attempt to install MSI packages via the Windows Installer COM object (`WindowsInstaller.Installer`) hosted remotely. This could be indication of malicious software deployment or lateral movement attempts using Windows Installer functionality. And the usage of WindowsInstaller COM object rather than msiexec could be an attempt to bypass the detection.

WindowsProcess Creation
Meroujan Antonyan (vx3r)Thu Jun 05windows
Detectionmediumexperimental

Potential PowerShell Console History Access Attempt via History File

Detects potential access attempts to the PowerShell console history directly via history file (ConsoleHost_history.txt). This can give access to plaintext passwords used in PowerShell commands or used for general reconnaissance.

WindowsProcess Creation
Luc GénauxThu Apr 03windows
Detectionhighexperimental

Suspicious Kerberos Ticket Request via CLI

Detects suspicious Kerberos ticket requests via command line using System.IdentityModel.Tokens.KerberosRequestorSecurityToken class. Threat actors may use command line interfaces to request Kerberos tickets for service accounts in order to perform offline password cracking attacks commonly known as Kerberoasting or other Kerberos ticket abuse techniques like silver ticket attacks.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Tue Nov 18windows