McAfee won't block it as a virus because it isn't one. It's a program, like any other, but it's a Fake AV program.
There's a removal guide at http://www.bleepingcomputer.com/virus-removal/remove-vista-internet-security-201 2 which should clear it from your PC. If you have any problems, download and run the McAfee Stinger program (you can get it from HERE).
Moved to Top Threats to be with the other threads about this Fake AV program