"Google Systems have detected unusual traffic from your computer. Please check you PC on viruses. To continue ,please download and install our antivirus software [DOWNLOAD_BUTTON] or our system will block your access to google services." reads the false warning.
Once users heed this fake warning, they download a rogue AV file contained in a password-protected archive. Of course, the archive is a malicious file , GFI identified this file as Trojan.Win32.Fakeav.tri(v).