Mustang Panda PlugX Delivery via HTML Smuggling
This rule detects the multi-stage delivery of PlugX malware, attributed to Mustang Panda, leveraging HTML smuggling, DLL side-loading, and persistence via registry run keys. The detection chain starts with a browser dropping an MSI file (HTML smuggling), followed by msiexec.exe executing a known sideloading executable (gup.exe or robotaskbaricon.exe). Subsequently, a malicious DLL (libcurl.dll or RoboForm.dll) is side-loaded by the executable from the same path, and finally, persistence is established through a registry run key by the same sideloading executable.
Microsoft Sentinel (KQL)
