According to DriveSentry, a security vendor, half of the currently distributed “cracked” versions of Windows are in fact malware.

Users who fall for the scam can end up with some pretty nasty problems, according to Lynch. DriveSentry researchers have found malicious key-logging software and spyware on about half of the downloads it has examined recently, he said.

So if you were considering trying out an illegal version of Vista anytime soon, it doesn’t look like the odds are too good. But in case you choose to do it anyway, try to download it from some P2P network that has a comment system. That won’t solve the issue, but it’s less likely for you get a malware instead.