Sigma Rules
294 rules found
Windows Suspicious Child Process from Node.js - React2Shell
Detects suspicious child processes started by Node.js server processes on Windows, which may indicate exploitation of vulnerabilities like CVE-2025-55182 (React2Shell). Attackers can abuse the Node.js 'child_process' module to run system commands or scripts using methods such as spawn(), exec(), execFile(), fork(), or execSync(). If execSync() or exec() is used in the exploit, the command line often shows a shell (e.g., cmd.exe /d /s /c ...) running a suspicious command unless other shells are explicitly invoked. For other methods, the spawned process appears directly in the Image field unless a shell is explicitly used.
Commvault QLogin with PublicSharingUser and GUID Password (CVE-2025-57788)
Detects a qlogin.exe command attempting to authenticate as the internal `_+_PublicSharingUser_` using a GUID as the password. This could be an indicator of an attacker exploiting CVE-2025-57788 to gain initial access using leaked credentials.
Commvault QOperation Path Traversal Webshell Drop (CVE-2025-57790)
Detects the use of qoperation.exe with the -file argument to write a JSP file to the webroot, indicating a webshell drop. This is a post-authentication step corresponding to CVE-2025-57790.
Commvault QLogin Argument Injection Authentication Bypass (CVE-2025-57791)
Detects the use of argument injection in the Commvault qlogin command - potential exploitation for CVE-2025-57791. An attacker can inject the `-localadmin` parameter via the password field to bypass authentication and gain a privileged token.
Exploitation Activity of CVE-2025-59287 - WSUS Suspicious Child Process
Detects the creation of command-line interpreters (cmd.exe, powershell.exe) as child processes of Windows Server Update Services (WSUS) related process wsusservice.exe. This behavior is a key indicator of exploitation for the critical remote code execution vulnerability such as CVE-2025-59287, where attackers spawn shells to conduct reconnaissance and further post-exploitation activities.
Exploitation Activity of CVE-2025-59287 - WSUS Deserialization
Detects cast exceptions in Windows Server Update Services (WSUS) application logs that highly indicate exploitation attempts of CVE-2025-59287, a deserialization vulnerability in WSUS.
Potential Exploitation of CVE-2025-5054 or CVE-2025-4598
Detects attempts of an attacker to enable core dumps for set-user-ID (SUID) processes by modifying the system file /proc/sys/fs/suid_dumpable, typically by setting its value to 1 or 2. Enabling this feature allows memory dumps (core dumps) of SUID processes, which usually run with elevated privileges. These dumps may contain sensitive information such as passwords, cryptographic keys or other secrets. CVE-2025-5054: Information leak via core dumps from SUID binaries using apport. CVE-2025-4598: Information disclosure in systemd-coredump due to insecure handling of SUID process memory dumps.
Atomic MacOS Stealer - Persistence Indicators
Detects creation of persistence artifacts placed by Atomic MacOS Stealer in macOS systems. Recent Atomic MacOS Stealer variants have been observed dropping these to maintain persistent access after compromise.
Atomic MacOS Stealer - FileGrabber Activity
Detects suspicious activity associated with Atomic MacOS Stealer (Amos) campaigns, including execution of FileGrabber and curl-based POST requests used for data exfiltration. The rule identifies either the execution of FileGrabber targeting /tmp or the use of curl to POST sensitive user data (including files such as /tmp/out.zip) to remote servers, which are key indicators of Amos infostealer activity.
FunkLocker Ransomware File Creation
Detects the creation of files with the ".funksec" extension, which is appended to encrypted files by the FunkLocker ransomware.
Grixba Malware Reconnaissance Activity
Detects execution of the Grixba reconnaissance tool based on suspicious command-line parameter combinations. This tool is used by the Play ransomware group for network enumeration, data gathering, and event log clearing.
DNS Query To Katz Stealer Domains
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.
Katz Stealer DLL Loaded
Detects loading of DLLs associated with Katz Stealer malware 2025 variants. Katz Stealer is a malware variant that is known to be used for stealing sensitive information from compromised systems. The process that loads these DLLs are very likely to be malicious.
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.
Katz Stealer Suspicious User-Agent
Detects network connections with a suspicious user-agent string containing "katz-ontop", which may indicate Katz Stealer activity.
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.
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
Shai-Hulud Malware Indicators - Linux
Detects potential Shai-Hulud malware indicators based on specific command line arguments associated with its execution.
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.
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.
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.
Shai-Hulud Malware Indicators - Windows
Detects potential Shai-Hulud malware indicators based on specific command line arguments associated with its execution.
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.
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.
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.
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.
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.
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
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.
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.
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.
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.
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.
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.
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.
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.
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.
Azure Sign-In With Axios User Agent
Detects sign-in attempts in Azure/Entra ID logs where the user agent contains "axios", indicating potential use of automated credential harvesting or AiTM phishing infrastructure. Axios is a Node.js HTTP client abused to intercept and replay stolen credentials and MFA tokens. When triaging results, analysts should: - Check the sign-in risk level, MFA status, and conditional access results for signs of bypass. - Look for sign-ins from unusual locations or IPs, especially if the same IP targets multiple accounts. - Prioritize successful sign-ins over failed ones, as they may indicate a completed credential replay or AiTM attack.
Inbox Rules Creation Or Update Activity in O365
Detects inbox rule creation or update via O365 Audit logs, a technique commonly observed in Business Email Compromise (BEC) attacks to hide emails. The usage of inbox rules can be a sign of a compromised mailbox, where an attacker is attempting to evade detections by suppressing or redirecting incoming emails. Analysts should review these rules in context, validate whether they reflect normal user behavior, and correlate with other indicators such as unusual login activity or recent mailbox rule modifications.
Potentially Suspicious Long Filename Pattern - Linux
Detects the creation of files with unusually long filenames (100 or more characters), which may indicate obfuscation techniques used by malware such as VShell. This is a hunting rule to identify potential threats that use long filenames to evade detection. Keep in mind that on a legitimate system, such long filenames can and are common. Run this detection in the context of threat hunting rather than alerting. Adjust the threshold of filename length as needed based on your environment.
Low Reputation Effective Top-Level Domain (eTLD)
Detects DNS queries to domains within known low reputation eTLDs. This rule uses AlphaSOC's threat intelligence data and is updated on a monthly basis.
Successful MSIX/AppX Package Installation
Detects successful MSIX/AppX package installations on Windows systems by monitoring EventID 854 in the Microsoft-Windows-AppXDeployment-Server/Operational log. While most installations are legitimate, this can help identify unauthorized or suspicious package installations. It is crucial to monitor such events as threat actors may exploit MSIX/AppX packages to deliver and execute malicious payloads.
WDAC Policy File Creation In CodeIntegrity Folder
Attackers can craft a custom Windows Defender Application Control (WDAC) policy that blocks Endpoint Detection and Response (EDR) components while allowing their own malicious code. The policy is placed in the privileged Windows Code Integrity folder (C:\Windows\System32\CodeIntegrity\). Upon reboot, the policy prevents EDR drivers from loading, effectively bypassing security measures and may further enable undetected lateral movement within an Active Directory environment.
BITS Client BitsProxy DLL Loaded By Uncommon Process
Detects an uncommon process loading the "BitsProxy.dll". This DLL is used when the BITS COM instance or API is used. This detection can be used to hunt for uncommon processes loading this DLL in your environment. Which may indicate potential suspicious activity occurring.
WerFaultSecure Loading DbgCore or DbgHelp - EDR-Freeze
Detects the loading of dbgcore.dll or dbghelp.dll by WerFaultSecure.exe, which has been observed in EDR-Freeze attacks to suspend processes and evade detection. However, this behavior has also been observed during normal software installations, so further investigation is required to confirm malicious activity. When threat hunting, look for this activity in conjunction with other suspicious processes starting, network connections, or file modifications that occur shortly after the DLL load. Pay special attention to timing - if other malicious activities occur during or immediately after this library loading, it may indicate EDR evasion attempts. Also correlate with any EDR/AV process suspension events or gaps in security monitoring during the timeframe.
Mail Forwarding/Redirecting Activity Via ExchangePowerShell Cmdlet
Detects email forwarding or redirecting activity via ExchangePowerShell Cmdlet
Inbox Rules Creation Or Update Activity Via ExchangePowerShell Cmdlet
Detects inbox rule creation or update via ExchangePowerShell cmdlet, a technique commonly observed in Business Email Compromise (BEC) attacks to hide emails. The usage of inbox rules can be a sign of a compromised mailbox, where an attacker is attempting to evade detections by suppressing or redirecting incoming emails. Analysts should review these rules in context, validate whether they reflect normal user behavior, and correlate with other indicators such as unusual login activity or recent mailbox rule modifications.
HTML File Opened From Download Folder
Detects web browser process opening an HTML file from a user's Downloads folder. This behavior is could be associated with phishing attacks where threat actors send HTML attachments to users. When a user opens such an attachment, it can lead to the execution of malicious scripts or the download of malware. During investigation, analyze the HTML file for embedded scripts or links, check for any subsequent downloads or process executions, and investigate the source of the email or message containing the attachment.