I am gettin sued for supposedly downloading an illegal movie?

some shady lawyer sent the court civil order to comcast, comcast sent it to me, got viruses on my computer, who knows what i clicked by mistake causing some downloading of something, plus 3 other people in my house use this internet service, i need to quash or vacate the subpoena, or comcast will give out my info in 30 days to them, i cant find much info on the term quash, has anybody dealt with this before? I looked into the guy suing me, seems like its entrapment and extortion, as i am including upon hundreds gettin sued. Another question, if i cancel comcast services could they still give out my info? just looking for some advice, free of course, im broke haha, anything would be most appreciated.