Weird CA hack??

So when I was on CA today i was looking for a game to play and found a quarantine game with only 2 people in it and it was in-game. When i joined the match room there was only one person in game so i decided to click start to see what was happening, as soon i got in there were other people inside and they were running on the spot so when the timer went down there was a slight freeze an then all of a sudden i got infected like 20 times and when i tried to exit my combat crashed, and my computer automatically restarted. Is this actually a public hack? I mean this hack really pissed me off because my computer takes pretty long to load and start up. If so could you please tell me what kind of hack this is??