Gootkit Loader operators use VLC Media Player as a post-exploitation tool

2 months ago · 0 comments

Trend Micro researchers warn that Gootkit Loader has targeted the Australian healthcare industry using SEO poisoning and VLC Media Player as Cobalt Strike.

SEO poisoning techniques use keywords such as "hospital", "health", "medicine" and "corporate agreement" in combination with the names of Australian cities. When searching for terms related to the Australian healthcare industry, "poisoned" sites appear on the first page of search results. When you open the site, a forum page appears that contains a link to download the ZIP file containing the malware.

The ZIP archive also contains a JavaScript file that is used for obfuscation and persistence through a scheduled task. The scheduled task runs a PowerShell script and retrieves the attack chain files from the C&C server.

The second stage of infection occurs after the waiting time, which lasts from several hours to two days. When the timeout expires, the payloads are removed (msdtc.exe and libvlc.dll). "msdtc.exe" is a VLC Media Player installer that pretends to be a legitimate Windows component. Using the DLL Sideloading method, the installer loads the "libvlc.dll" library with the Cobalt Strike module, and then functions as Cobalt Strike itself.