I'm sure if it does detect a virus, there is a much clearer warning of the result. For some reason, it seems to hide the results away in a little box underneath the drag and drop target but you can expand it by clicking the arrow. Simply drag your file into the McAfee VirusScan and it will scan it instantly. This is useful if you've received a file and are unsure whether it's safe to open.
McAfee VirusScan isn't a real-time virus checker - rather it does one of scans of files you're worried about simply by dragging and dropping them into the interface. I've never had any virus problems on my Mac so far but a tool like this can never hurt. If you get over the rather lengthy installation process, then McAfee VirusScan (formerly known as McAfee Virex) is a no fuss and quick virus checker.
