Question: how do you know if your phone has a virus on it?
Answer: Data usage: The first sign that your phone has a virus is the rapid depletion of its data. ... 
Crashing apps: There you are, playing Angry Birds on your phone, and it suddenly crashes. ... 
Pop-ups: Many websites have pop-up ads. ... 
Unexplained charges: Ads and crashing apps are annoying.