Experienced users will probably have a quick glance at the stark look of the email and immediately conclude that the email is fake, but inexperienced ones might believe that Microsoft delivers Windows licenses in this way and follow the link.
Those that do will be redirected to through a number of .ru websites, one of which hosts the Blackhole exploit kit, warns GFI.
While the kit does its magic and downloads the Cridex information-stealing Trojan on the targeted computer, the victims possible suspicions are allayed by a bogus "Please wait a moment. You will be forwarded.." note on the final website.
If you know a person that might fall for this trick, please warn them about the scam.