Rule Library

Sigma Rules

3,132 rules found for "sigma"

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

Uncommon Child Process Of BgInfo.EXE

Detects uncommon child processes of "BgInfo.exe" which could be a sign of potential abuse of the binary to proxy execution via external VBScript

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)+2Sat Oct 26windows
Detectionlowtest

BitLockerTogo.EXE Execution

Detects the execution of "BitLockerToGo.EXE". BitLocker To Go is BitLocker Drive Encryption on removable data drives. This feature includes the encryption of, USB flash drives, SD cards, External hard disk drives, Other drives that are formatted by using the NTFS, FAT16, FAT32, or exFAT file system. This is a rarely used application and usage of it at all is worth investigating. Malware such as Lumma stealer has been seen using this process as a target for process hollowing.

WindowsProcess Creation
Josh Nickels+1Thu Jul 11windows
Detectionmediumtest

File Download Via Bitsadmin

Detects usage of bitsadmin downloading a file

WindowsProcess Creation
Michael Haag+1Thu Mar 09windows
Detectionhightest

Suspicious Download From Direct IP Via Bitsadmin

Detects usage of bitsadmin downloading a file using an URL that contains an IP

WindowsProcess Creation
Florian Roth (Nextron Systems)Tue Jun 28windows
Detectionhightest

Suspicious Download From File-Sharing Website Via Bitsadmin

Detects usage of bitsadmin downloading a file from a suspicious domain

WindowsProcess Creation
Florian Roth (Nextron Systems)Tue Jun 28windows
Detectionhightest

File With Suspicious Extension Downloaded Via Bitsadmin

Detects usage of bitsadmin downloading a file with a suspicious extension

WindowsProcess Creation
Florian Roth (Nextron Systems)+1Tue Jun 28windows
Detectionhightest

File Download Via Bitsadmin To A Suspicious Target Folder

Detects usage of bitsadmin downloading a file to a suspicious target folder

WindowsProcess Creation
Florian Roth (Nextron Systems)+1Tue Jun 28windows
Detectionmediumtest

Monitoring For Persistence Via BITS

BITS will allow you to schedule a command to execute after a successful download to notify you that the job is finished. When the job runs on the system the command specified in the BITS job will be executed. This can be abused by actors to create a backdoor within the system and for persistence. It will be chained in a BITS job to schedule the download of malware/additional binaries and execute the program after being downloaded.

WindowsProcess Creation
SreemanThu Oct 29windows
Detectionhightest

Potential Data Stealing Via Chromium Headless Debugging

Detects chromium based browsers starting in headless and debugging mode and pointing to a user profile. This could be a sign of data stealing or remote control

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Fri Dec 23windows
Detectionlowtest

Browser Execution In Headless Mode

Detects execution of Chromium based browser in headless mode

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Tue Sep 12windows
Detectionhightest

File Download with Headless Browser

Detects execution of chromium based browser in headless mode using the "dump-dom" command line to download files

WindowsProcess Creation
Sreeman+1Tue Jan 04windows
Detectionmediumtest

Chromium Browser Instance Executed With Custom Extension

Detects a Chromium based browser process with the 'load-extension' flag to start a instance with a custom extension

WindowsProcess Creation
Aedan Russell+2Sun Jun 19windows
Detectionhightest

Chromium Browser Headless Execution To Mockbin Like Site

Detects the execution of a Chromium based browser process with the "headless" flag and a URL pointing to the mockbin.org service (which can be used to exfiltrate data).

WindowsProcess Creation
X__Junior (Nextron Systems)Mon Sep 11windows
Detectionhightest

Suspicious Chromium Browser Instance Executed With Custom Extension

Detects a suspicious process spawning a Chromium based browser process with the 'load-extension' flag to start an instance with a custom extension

WindowsProcess Creation
Aedan Russell+2Sun Jun 19windows
Detectionmediumtest

File Download From Browser Process Via Inline URL

Detects execution of a browser process with a URL argument pointing to a file with a potentially interesting extension. This can be abused to download arbitrary files or to hide from the user for example by launching the browser in a minimized state.

WindowsProcess Creation
Florian Roth (Nextron Systems)+1Tue Jan 11windows
Detectionmediumtest

Browser Started with Remote Debugging

Detects browsers starting with the remote debugging flags. Which is a technique often used to perform browser injection attacks

WindowsProcess Creation
Martin Mueller+1Wed Jul 27windows
Detectionhightest

Tor Client/Browser Execution

Detects the use of Tor or Tor-Browser to connect to onion routing networks

WindowsProcess Creation
François HubautSun Feb 20windows
Detectionhightest

Suspicious Calculator Usage

Detects suspicious use of 'calc.exe' with command line parameters or in a suspicious directory, which is likely caused by some PoC or detection evasion.

WindowsProcess Creation
Florian Roth (Nextron Systems)Sat Feb 09windows
Detectionmediumtest

Potential Binary Proxy Execution Via Cdb.EXE

Detects usage of "cdb.exe" to launch arbitrary processes or commands from a debugger script file

WindowsProcess Creation
Beyu Denis+2Sat Oct 26windows
Detectionmediumtest

New Root Certificate Installed Via CertMgr.EXE

Detects execution of "certmgr" with the "add" flag in order to install a new certificate on the system. Adversaries may install a root certificate on a compromised system to avoid warnings when connecting to adversary controlled web servers.

WindowsProcess Creation
oscd.community+1Sun Mar 05windows
Detectionmediumtest

File Download via CertOC.EXE

Detects when a user downloads a file by using CertOC.exe

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Mon May 16windows
Detectionhightest

File Download From IP Based URL Via CertOC.EXE

Detects when a user downloads a file from an IP based URL using CertOC.exe

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Wed Oct 18windows
Detectionmediumtest

DLL Loaded via CertOC.EXE

Detects when a user installs certificates by using CertOC.exe to loads the target DLL file.

WindowsProcess Creation
Austin SongerSat Oct 23windows
Detectionhightest

Suspicious DLL Loaded via CertOC.EXE

Detects when a user installs certificates by using CertOC.exe to load the target DLL file.

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Wed Feb 15windows
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
Detectionmediumtest

New Root Certificate Installed Via Certutil.EXE

Detects execution of "certutil" with the "addstore" flag in order to install a new certificate on the system. Adversaries may install a root certificate on a compromised system to avoid warnings when connecting to adversary controlled web servers.

WindowsProcess Creation
oscd.community+1Sun Mar 05windows
Detectionhightest

File Decoded From Base64/Hex Via Certutil.EXE

Detects the execution of certutil with either the "decode" or "decodehex" flags to decode base64 or hex encoded files. This can be abused by attackers to decode an encoded payload before execution

WindowsProcess Creation
Florian Roth (Nextron Systems)+2Wed Feb 15windows
Detectionmediumtest

Suspicious Download Via Certutil.EXE

Detects the execution of certutil with certain flags that allow the utility to download files.

WindowsProcess Creation
Florian Roth (Nextron Systems)+3Wed Feb 15windows
Detectionhightest

Suspicious File Downloaded From Direct IP Via Certutil.EXE

Detects the execution of certutil with certain flags that allow the utility to download files from direct IPs.

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Wed Feb 15windows
Detectionhightest

Suspicious File Downloaded From File-Sharing Website Via Certutil.EXE

Detects the execution of certutil with certain flags that allow the utility to download files from file-sharing websites.

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Wed Feb 15windows
Detectionmediumtest

File Encoded To Base64 Via Certutil.EXE

Detects the execution of certutil with the "encode" flag to encode a file to base64. This can be abused by threat actors and attackers for data exfiltration

WindowsProcess Creation
Florian Roth (Nextron Systems)+3Sun Feb 24windows
Detectionhightest

Suspicious File Encoded To Base64 Via Certutil.EXE

Detects the execution of certutil with the "encode" flag to encode a file to base64 where the extensions of the file is suspicious

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Mon May 15windows
Detectionhightest

File In Suspicious Location Encoded To Base64 Via Certutil.EXE

Detects the execution of certutil with the "encode" flag to encode a file to base64 where the files are located in potentially suspicious locations

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Mon May 15windows
Detectionmediumtest

Certificate Exported Via Certutil.EXE

Detects the execution of the certutil with the "exportPFX" flag which allows the utility to export certificates.

WindowsProcess Creation
Florian Roth (Nextron Systems)+3Wed Feb 15windows
Detectionhightest

Potential NTLM Coercion Via Certutil.EXE

Detects possible NTLM coercion via certutil using the 'syncwithWU' flag

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

Console CodePage Lookup Via CHCP

Detects use of chcp to look up the system locale value as part of host discovery

WindowsProcess Creation
_pete_0+1Mon Feb 21windows
Detectionmediumtest

Suspicious CodePage Switch Via CHCP

Detects a code page switch in command line or batch scripts to a rare language

WindowsProcess Creation
Florian Roth (Nextron Systems)+2Mon Oct 14windows
Detectionmediumtest

Deleted Data Overwritten Via Cipher.EXE

Detects usage of the "cipher" built-in utility in order to overwrite deleted data from disk. Adversaries may destroy data and files on specific systems or in large numbers on a network to interrupt availability to systems, services, and network resources. Data destruction is likely to render stored data irrecoverable by forensic techniques through overwriting files or data on local and remote drives

WindowsProcess Creation
François HubautSun Dec 26windows
Detectionhightest

Process Access via TrolleyExpress Exclusion

Detects a possible process memory dump that uses the white-listed Citrix TrolleyExpress.exe filename as a way to dump the lsass process memory

WindowsProcess Creation
Florian Roth (Nextron Systems)Thu Feb 10windows
Detectionlowtest

Data Copied To Clipboard Via Clip.EXE

Detects the execution of clip.exe in order to copy data to the clipboard. Adversaries may collect data stored in the clipboard from users copying information within or between applications.

WindowsProcess Creation
François HubautTue Jul 27windows
Detectionmediumtest

Cloudflared Portable Execution

Detects the execution of the "cloudflared" binary from a non standard location.

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Wed Dec 20windows
Detectionmediumtest

Cloudflared Quick Tunnel Execution

Detects creation of an ad-hoc Cloudflare Quick Tunnel, which can be used to tunnel local services such as HTTP, RDP, SSH and SMB. The free TryCloudflare Quick Tunnel will generate a random subdomain on trycloudflare[.]com, following a call to api[.]trycloudflare[.]com. The tool has been observed in use by threat groups including Akira ransomware.

WindowsProcess Creation
Sajid Nawaz KhanWed Dec 20windows
Detectionmediumtest

Cloudflared Tunnel Connections Cleanup

Detects execution of the "cloudflared" tool with the tunnel "cleanup" flag in order to cleanup tunnel connections.

WindowsProcess Creation
Nasreddine Bencherchali (Nextron Systems)Wed May 17windows
Detectionmediumtest

Cloudflared Tunnel Execution

Detects execution of the "cloudflared" tool to connect back to a tunnel. This was seen used by threat actors to maintain persistence and remote access to compromised networks.

WindowsProcess Creation
Janantha Marasinghe+1Wed May 17windows
Detectionmediumtest

New Generic Credentials Added Via Cmdkey.EXE

Detects usage of "cmdkey.exe" to add generic credentials. As an example, this can be used before connecting to an RDP session via command line interface.

WindowsProcess Creation
François Hubaut+1Fri Feb 03windows
Detectionhightest

Potential Reconnaissance For Cached Credentials Via Cmdkey.EXE

Detects usage of cmdkey to look for cached credentials on the system

WindowsProcess Creation
jmallette+2Wed Jan 16windows
Detectionmediumtest

Potential Arbitrary File Download Via Cmdl32.EXE

Detects execution of Cmdl32 with the "/vpn" and "/lan" flags. Attackers can abuse this utility in order to download arbitrary files via a configuration file. Inspect the location and the content of the file passed as an argument in order to determine if it is suspicious.

WindowsProcess Creation
François HubautWed Nov 03windows
Detectionlowtest

Change Default File Association Via Assoc

Detects file association changes using the builtin "assoc" command. When a file is opened, the default program used to open the file (also called the file association or handler) is checked. File association selections are stored in the Windows Registry and can be edited by users, administrators, or programs that have Registry access or by administrators using the built-in assoc utility. Applications can modify the file association for a given file extension to call an arbitrary program when a file with the given extension is opened.

WindowsProcess Creation
Timur Zinniatullin+1Mon Oct 21windows