Win32:BackoffPOS-Q[Trj] Removal Guide - How to Remove Trojan Virus

Since a couple of days ago I constantly get this message. I have no idea, what's wrong with it. When I scan the file manually there seems to be nothing wrong with it. Any ideas on how to fix this? It's pretty annoying.

 

Information of Win32:BackoffPOS-Q[Trj]

Win32:BackoffPOS-Q[Trj] is a Trojan infection which can get into the computer along with free downloads from the Internet, such as browser update, Java update, Flash Player update, Video Player update, video recording, download-managers or PDF creators. It can also come with spam email attachment or hacked links or sites. This is a self-extracting archive and installer and has been known to bundle potentially unwanted software. This Trojan installer database contains the logic and data required to install Win32:BackoffPOS-Q[Trj].