This is a rare and odd occurrence on a Mac and probably has nothing to do with PS.
Basically, something went wrong in the OS somewhere and the computer can no longer remain running (you have to restart). If this happens repeatedly while playing PS, you should report it again. If it\'s only that once, though, I wouldn\'t worry.
P.S. It\'s nigh impossible to get a virus on a Mac, and even more unlikely to get one from PS.