Rule Library

Sigma Rules

457 rules found

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

DNS Query To Katz Stealer Domains - Network

Detects DNS queries to domains associated with Katz Stealer malware. Katz Stealer is a malware variant that is known to be used for stealing sensitive information from compromised systems. In Enterprise environments, DNS queries to these domains may indicate potential malicious activity or compromise.

dns
Swachchhanda Shrawan Poudel (Nextron Systems)Thu May 222025
Emerging Threathighexperimental

Katz Stealer Suspicious User-Agent

Detects network connections with a suspicious user-agent string containing "katz-ontop", which may indicate Katz Stealer activity.

Zeek (Bro)http
Swachchhanda Shrawan Poudel (Nextron Systems)Thu May 222025
Emerging Threathighexperimental

Kalambur Backdoor Curl TOR SOCKS Proxy Execution

Detects the execution of the "curl.exe" command, referencing "SOCKS" and ".onion" domains, which could be indicative of Kalambur backdoor activity.

WindowsProcess Creation
Arda Buyukkaya (EclecticIQ)Tue Feb 112025
Emerging Threathighexperimental

Shai-Hulud Malicious GitHub Workflow Creation

Detects creation of shai-hulud-workflow.yml file associated with Shai Hulud worm targeting NPM supply chain attack that exfiltrates GitHub secrets

LinuxFile Event
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Sep 242025
Emerging Threathighexperimental

Shai-Hulud Malware Indicators - Linux

Detects potential Shai-Hulud malware indicators based on specific command line arguments associated with its execution.

LinuxProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Tue Nov 252025
Emerging Threathighexperimental

Shai-Hulud Malicious Bun Execution - Linux

Detects the execution of `bun_environment.js` via the Bun runtime, a behavior associated with the Shai-Hulud "Second Coming" NPM supply chain attack. The malware uses a `setup_bun.js` script to install the Bun runtime if not present, and then executes the malicious `bun_environment.js` payload.

LinuxProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Tue Nov 252025
Emerging Threathighexperimental

Shai-Hulud 2.0 Malicious NPM Package Installation - Linux

Detects the command-line installation of specific malicious npm packages and versions associated with the Shai-Hulud 2.0 supply chain attack.

LinuxProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Fri Nov 282025
Emerging Threathighexperimental

Shai-Hulud NPM Package Malicious Exfiltration via Curl

Detects potential Shai Hulud NPM package attack attempting to exfiltrate data via curl to external webhook sites.

LinuxProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Sep 242025
Emerging Threathighexperimental

Shai-Hulud Malware Indicators - Windows

Detects potential Shai-Hulud malware indicators based on specific command line arguments associated with its execution.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Tue Nov 252025
Emerging Threathighexperimental

Shai-Hulud Malicious Bun Execution

Detects the execution of `bun_environment.js` via the Bun runtime, a behavior associated with the Shai-Hulud "Second Coming" NPM supply chain attack. The malware uses a `setup_bun.js` script to install the Bun runtime if not present, and then executes the malicious `bun_environment.js` payload.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Tue Nov 252025
Emerging Threathighexperimental

Shai-Hulud 2.0 Malicious NPM Package Installation

Detects the command-line installation of specific malicious npm packages and versions associated with the Shai-Hulud 2.0 supply chain attack.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Fri Nov 282025
Emerging Threathightest

Potential CVE-2026-33829 Exploitation - Windows Snipping Tool Remote File Path URI

Detects potential exploitation of CVE-2026-33829, a vulnerability in the Windows Snipping Tool URI handler (ms-screensketch:). An attacker can abuse the 'filePath' parameter to supply a UNC path or HTTP URL, causing SnippingTool.exe to initiate a connection to a remote resource. When a UNC path is used (e.g. \\attacker.com\share), this triggers an outbound NTLM authentication attempt, allowing the attacker to capture or relay the victim's Net-NTLMv2 hash. HTTP-based paths may result in remote file loading or server-side request forgery (SSRF)-style access. The URI can be delivered via a malicious hyperlink, phishing email, or web page.

WindowsProcess Creation
Samir Bousseaden+1Tue Apr 282026
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 Threathighexperimental

RedSun - Conhost.exe Spawned by TieringEngineService.exe

Detects two stages of the RedSun post-exploitation process chain that deliver a SYSTEM-level shell to the attacker's interactive session. Observed process chain services.exe → TieringEngineService.exe → conhost.exe (SYSTEM, CommandLine: bare path, no arguments) → cmd.exe / shell (SYSTEM, TerminalSessionId = attacker's session) Stage 1 — TieringEngineService.exe spawns argument-less conhost.exe: After winning the oplock + Cloud Files mount point race, the malicious TieringEngineService.exe (RedSun.exe copied to System32, started via CoCreateInstance / services.exe) detects it is NT AUTHORITY\SYSTEM and calls LaunchConsoleInSessionId(). This opens \\.\pipe\REDSUN, reads the attacker's session ID, duplicates the SYSTEM token, re-stamps it with that session ID via SetTokenInformation(TokenSessionId), then calls CreateProcessAsUser to spawn conhost.exe with no arguments. Stage 2 — Shell spawned from rogue conhost.exe (EDR sources with GrandParentImage): The rogue SYSTEM conhost.exe spawns a shell (cmd.exe, PowerShell, etc.) as SYSTEM in the attacker's interactive session. On EDR sources that expose GrandParentImage, the full three-level chain (TieringEngineService.exe → conhost.exe → shell) can be matched directly. The legitimate TieringEngineService.exe is a headless COM server that is unlikely to spawn conhost.exe under normal conditions.

WindowsProcess Creation
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
Emerging Threathighexperimental

Axios NPM Compromise File Creation Indicators - Linux

Detects file creation events linked to the Axios NPM supply chain compromise. Axios is a popular JavaScript HTTP client. On March 30, 2026, malicious versions (1.14.1, 0.30.4) were published to npm, injecting a dependency (plain-crypto-js@4.2.1) that executed a postinstall script as a cross-platform RAT dropper.

LinuxFile Event
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Apr 012026
Emerging Threathighexperimental

Axios NPM Compromise File Creation Indicators - MacOS

Detects file creation events linked to the Axios NPM supply chain compromise on macOS devices. Axios is a popular JavaScript HTTP client. On March 30, 2026, malicious versions (1.14.1, 0.30.4) were published to npm, injecting a dependency (plain-crypto-js@4.2.1) that executed a postinstall script as a cross-platform RAT dropper.

macOSFile Event
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Apr 012026
Emerging Threathighexperimental

Axios NPM Compromise File Creation Indicators - Windows

Detects file creation events linked to the Axios NPM supply chain compromise. Axios is a popular JavaScript HTTP client. On March 30, 2026, malicious versions (1.14.1, 0.30.4) were published to npm, injecting a dependency (plain-crypto-js@4.2.1) that executed a postinstall script as a cross-platform RAT dropper. The dropper contacted a C2 server, delivered platform-specific payloads, deleted itself, and replaced package.json to evade detection. The attack used cscript.exe (VBScript), curl.exe (C2), and PowerShell masquerading as Windows Terminal.

WindowsFile Event
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Apr 012026
Emerging Threathighexperimental

Axios NPM Compromise Malicious C2 Domain DNS Query

Detects DNS queries for the malicious C2 domain associated with the plain-crypto-js/Axios npm package supply chain compromise. On March 30, 2026, malicious versions (1.14.1, 0.30.4) were published to npm, injecting a dependency (plain-crypto-js@4.2.1) that executed a postinstall script as a cross-platform RAT dropper. This detection detects endpoints attempting to resolve the attacker's C2 domain (sfrclak.com) used for command and control communication.

dns
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Apr 012026
Emerging Threathighexperimental

Axios NPM Compromise Indicators - Linux

Detects the Linux-specific execution chain of the plain-crypto-js malicious npm dependency by Axios NPM package, including payload download via curl and detached execution using nohup and python3. On March 30, 2026, malicious versions (1.14.1, 0.30.4) were published to npm, injecting a dependency (plain-crypto-js@4.2.1) that executed a postinstall script as a cross-platform RAT dropper. The dropper contacted a C2 server, delivered platform-specific payloads, deleted itself, and replaced package.json to evade detection.

LinuxProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Apr 012026
Emerging Threathighexperimental

Axios NPM Compromise Indicators - macOS

Detects the macOS-specific execution chain of the plain-crypto-js malicious npm dependency in Axios NPM Package, including AppleScript execution via osascript, payload download, permission modification, execution, and cleanup.

macOSProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Apr 012026
Emerging Threathighexperimental

Axios NPM Compromise Indicators - Windows

Detects the specific Windows execution chain and process tree associated with the Axios NPM supply chain compromise. On March 30, 2026, malicious versions (1.14.1, 0.30.4) were published to npm, injecting a dependency (plain-crypto-js@4.2.1) that executed a postinstall script as a cross-platform RAT dropper. The dropper contacted a C2 server, delivered platform-specific payloads, deleted itself, and replaced package.json to evade detection. The attack used cscript.exe (VBScript), curl.exe (C2), and PowerShell masquerading as Windows Terminal.

WindowsProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Wed Apr 012026
Emerging Threathighexperimental

TeamPCP LiteLLM Supply Chain Attack Persistence Indicators

Detects the creation of specific persistence files as observed in the LiteLLM PyPI supply chain attack. In March 2026, a supply chain attack was discovered involving the popular open-source LLM framework LiteLLM by Threat Actor TeamPCP. The malicious package harvests every credential on the system, encrypts and exfiltrates them, and installs a persistent C2 backdoor.

LinuxFile Event
Swachchhanda Shrawan Poudel (Nextron Systems)Mon Mar 302026
Emerging Threathighexperimental

LiteLLM / TeamPCP Supply Chain Attack Indicators

Detects process executions related to the backdoored versions of LiteLLM (v1.82.7 or v1.82.8). In March 2026, a supply chain attack was discovered involving the popular open-source LLM framework LiteLLM by Threat Actor TeamPCP. The malicious package harvests every credential on the system, encrypts and exfiltrates them, and installs a persistent C2 backdoor.

LinuxProcess Creation
Swachchhanda Shrawan Poudel (Nextron Systems)Mon Mar 302026