Avuntil.51.dll what the hell?

So there was a pop up about avuntil.51.dll whenever i wanted to play a game through steam. Though this was an issue with the game or something but now I have the same pop up when trying a different game not through steam. (game isnt loading)

Decided to ask uncle google abouth this but it came up with some confusing stuff.  

Anyone know how to solve this ??

http://imgur.com/r/Steam/iEMX2

yeah in pro version it said its not a vir.