Sigma detection rules, expert-reviewed

Malicious Lazarus Rundll32 Execution of Sup ETL Privilege Escalation Loader (via process_creation)

This rule detects rundll32.exe executing a sup.etl file from the USOShared directory using the SerializeMarketTable export as observed in the Lazarus attack on Windows web servers. Loading an etl file as a DLL through an unusual export is a strong indicator of this loader.

IFM Detected - ESENT - Installation from Media (via application)

This rule detects create an IFM image (usually used for deploying domain controllers to reduce replication traffic) for dumping credentials.

Suspicious Privileged Group Membership Change via net.exe (via process_creation)

This rule detects net.exe adding an account to a privileged local group such as Administrators or Remote Desktop Users. Medusa operators manipulate group membership to escalate privileges and retain access, so an account addition to a sensitive group during an intrusion is a persistence and privilege-escalation signal.

Enable WDigest using PowerShell

Rule to detect registry modifications to enable WDigest using powershell over the commandline.

Suspicious SSH Reverse Tunnel Over Port 443 via ssh.exe by UNC1549

This rule detects the native Windows ssh.exe client establishing a reverse tunnel with the -R flag over port 443 as observed in UNC1549 operations. Attackers tunnel internal services outbound over an HTTPS port to blend with normal web traffic and bypass egress controls.

Malicious PowerShell Download Cradle via Invoke-WebRequest and IEX

This rule detects PowerShell run with an execution policy bypass that downloads content and pipes it directly to Invoke-Expression. Stealerium uses powershell -eP Bypass with Invoke-WebRequest to pull an atom feed from a blogspot dead drop and execute it in memory with IEX. This download-and-execute cradle is a widely abused fileless staging technique.

Suspicious Scheduled Task Masquerading as Edge Update Telemetry (via process_creation)

This rule detects creation of a scheduled task using the distinctive name CoreEdgeUpdateServicesTelemetry FallBack. The FLUX#CONSOLE campaign registered this task to run its sideloading Dism binary every five minutes for persistence.

Suspicious Execution From WinRAR Temporary Extraction Path via Command Line (via process_creation)

This rule detects process execution referencing the WinRAR temporary extraction directory pattern Rar$ under the local Temp folder, which the CVE-2023-38831 exploit uses to run its planted payload. It is associated with attacks abusing the WinRAR archive spoofing zero-day reported by Uptycs. Because scripts and binaries executed straight from this transient extraction path are characteristic of the exploit, this pattern indicates likely code execution from a crafted archive.

Malicious PlugX Sideload via Acrobat.dll

This rule detects the signed Acrobat.exe loading an Acrobat.dll from a location outside Program Files. This behavior matches CL-STA-0048 where operators sideloaded a malicious Acrobat.dll implementing PlugX which then injected into svchost.exe. A trusted Adobe binary loading its companion DLL from a non-standard path is a sideloading indicator of espionage malware.

Suspicious Silent MSI Installation from AppData Spawned by PowerShell (via process_creation)

This rule detects msiexec.exe spawned by PowerShell to silently install an MSI staged in the user AppData directory, the second step of the Bumblebee loader chain where PowerShell writes y.msi to AppData and installs it with no user interaction. Legitimate software rarely installs MSIs from AppData under a PowerShell parent, so this parent-child and path combination surfaces the loader stage.

Suspicious node.exe Inline Script Execution via -e

This rule detects node.exe executing an inline script through the -e flag, the stager execution method in the DEV#POPPER GitHub-lure infection. Victims who cloned the weaponized repository ran a hidden script that used node -e to bootstrap the RAT. While developers occasionally use node -e, inline Node execution from a cloned project should be reviewed for malicious staging.

Suspicious AppLaunch.exe Execution as Process Hollowing Target

This rule detects the .NET ClickOnce host AppLaunch.exe running with a parent other than a legitimate development tool. Titan Stealer hollows AppLaunch.exe and injects its XOR-decoded Golang stealer into the trusted signed binary to evade detection. AppLaunch.exe spawned outside of Visual Studio or build tooling is a common injection and masquerading target.

Driverquery Lookup

Detects use of driverquery to look up the installed and configured drivers as part of host discovery

Suspicious CoffeeLoader Execution via Armoury Crate DLL Side-Loading (via process_creation)

This rule detects rundll32 executing the ArmouryAIOSDK.dll with the Post_EntrypointReturn export that CoffeeLoader uses to run its stager through DLL side-loading of ASUS Armoury Crate. Legitimate Armoury Crate components are not invoked this way from user writable paths.

Malicious Metasploit PsExec Named Pipe Command Execution

This rule detects a command shell echoing data into a local named pipe, the service-based execution pattern produced by the Metasploit PsExec module when it installs a service that writes command output back through a pipe. This is used for remote code execution and lateral movement from a compromised host. Legitimate software does not echo into a raw named pipe from cmd.exe in this way.