Rapid7 has observed an ongoing campaign to distribute trojanized installers for WinSCP and PuTTY via malicious ads on commonly used search engines, where clicking on the ad leads to typo squatted domains.

Threat actors associated with the BlackCat ransomware have been observed employing malvertising tricks to distribute rogue installers of the WinSCP file transfer application.

We found that malicious actors used malvertising to distribute malware via cloned webpages of legitimate organizations. The distribution involved a webpage of the well-known application WinSCP, an open-source Windows application for file transfer. We were able to identify that this activity led to a BlackCat (aka ALPHV) infection, and actors also used SpyBoy, a terminator that tampers with protection provided by agents.