Norton 360 Blocking Trojan.AdClicker. ???

I don't know how my computers keep getting infected, this the 2nd computer my kids use get infected in the last month. I use Norton 360 and Malwarebytes premium to protect them. Malwarebytes premium which I purchased after the other computer was infected was running also when this computer was infected.

I'll be able to check the forum for directions and complete requested task anytime the next 2 days.