Sigma Rules
3,116 rules found
Browser Execution In Headless Mode
Detects execution of Chromium based browser in headless mode
File Download with Headless Browser
Detects execution of chromium based browser in headless mode using the "dump-dom" command line to download files
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
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).
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
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.
Browser Started with Remote Debugging
Detects browsers starting with the remote debugging flags. Which is a technique often used to perform browser injection attacks
Tor Client/Browser Execution
Detects the use of Tor or Tor-Browser to connect to onion routing networks
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.
Potential Binary Proxy Execution Via Cdb.EXE
Detects usage of "cdb.exe" to launch arbitrary processes or commands from a debugger script file
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.
File Download via CertOC.EXE
Detects when a user downloads a file by using CertOC.exe
File Download From IP Based URL Via CertOC.EXE
Detects when a user downloads a file from an IP based URL using CertOC.exe
DLL Loaded via CertOC.EXE
Detects when a user installs certificates by using CertOC.exe to loads the target DLL file.
Suspicious DLL Loaded via CertOC.EXE
Detects when a user installs certificates by using CertOC.exe to load the target DLL file.
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.
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.
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
Suspicious Download Via Certutil.EXE
Detects the execution of certutil with certain flags that allow the utility to download files.
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.
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.
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
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
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
Certificate Exported Via Certutil.EXE
Detects the execution of the certutil with the "exportPFX" flag which allows the utility to export certificates.
Potential NTLM Coercion Via Certutil.EXE
Detects possible NTLM coercion via certutil using the 'syncwithWU' flag
Console CodePage Lookup Via CHCP
Detects use of chcp to look up the system locale value as part of host discovery
Suspicious CodePage Switch Via CHCP
Detects a code page switch in command line or batch scripts to a rare language
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
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
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.
Cloudflared Portable Execution
Detects the execution of the "cloudflared" binary from a non standard location.
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.
Cloudflared Tunnel Connections Cleanup
Detects execution of the "cloudflared" tool with the tunnel "cleanup" flag in order to cleanup tunnel connections.
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.
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.
Change Default File Association To Executable Via Assoc
Detects when a program changes the default file association of any extension to an executable. 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.
Copy .DMP/.DUMP Files From Remote Share Via Cmd.EXE
Detects usage of the copy builtin cmd command to copy files with the ".dmp"/".dump" extension from a remote share
Curl Download And Execute Combination
Adversaries can use curl to download payloads remotely and execute them. Curl is included by default in Windows 10 build 17063 and later.
File Deletion Via Del
Detects execution of the builtin "del"/"erase" commands in order to delete files. Adversaries may delete files left behind by the actions of their intrusion activity. Malware, tools, or other non-native files dropped or created on a system by an adversary may leave traces to indicate to what was done within a network and how. Removal of these files can occur during an intrusion, or as part of a post-intrusion process to minimize the adversary's footprint.
Greedy File Deletion Using Del
Detects execution of the "del" builtin command to remove files using greedy/wildcard expression. This is often used by malware to delete content of folders that perhaps contains the initial malware infection or to delete evidence.
File And SubFolder Enumeration Via Dir Command
Detects usage of the "dir" command part of Windows CMD with the "/S" command line flag in order to enumerate files in a specified directory and all subdirectories.
Potential Dosfuscation Activity
Detects possible payload obfuscation via the commandline
Command Line Execution with Suspicious URL and AppData Strings
Detects a suspicious command line execution that includes an URL and AppData string in the command line parameters as used by several droppers (js/vbs > powershell)
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.
Potential Privilege Escalation Using Symlink Between Osk and Cmd
Detects the creation of a symbolic link between "cmd.exe" and the accessibility on-screen keyboard binary (osk.exe) using "mklink". This technique provides an elevated command prompt to the user from the login screen without the need to log in.
VolumeShadowCopy Symlink Creation Via Mklink
Shadow Copies storage symbolic link creation using operating systems utilities
Suspicious File Execution From Internet Hosted WebDav Share
Detects the execution of the "net use" command to mount a WebDAV server and then immediately execute some content in it. As seen being used in malicious LNK files