It turns out that one of the features of Windows designed to help the disabled could actually lead to a security hole. StickyKeys is what's known as an 'accessibility' feature - instead of having to press two keys at once, such as Ctrl-C to copy, the user can press Ctrl first and then hit C, if StickyKeys is turned on. To do so, you tap the Shift key five times in a row.

The problem is that Vista doesn't check to make sure that the StickyKeys program is the correct one, according to a McAfee security researcher. When you tap the Shift key, Vista launches a program called sethc.exe, but it doesn't make sure it's the right file. So if the file is replaced with a program that causes problems or gives an attacker access to the system, you're in trouble.

There are a couple of reasons not to worry, though. Firstly, the attacker would need physical access to the computer to install the bad file over the good one. He'd also need to get you to turn StickyKeys on to get the thing going.