Filterbit is an online service available for scanning a file for virus with out installing any antivirus software on the client machine.This online service can be used to double check the files which you downloaded from insecure websites.Filterbit can not only scan for virus,but also identify the duplicate files contained in the archive such as Winzip, WinRar, PKZip etc.
Filterbit makes use of antivirus scan provided by  Kaspersky,AVG,McAfee VirusScan,  ClamWin, CA,  Norman etc.We can upload our files for scanning and the filterbit will identify viruses, trojans, worms and other malware that may be contained within your uploaded files.

But the major drawback of filterbit is it cant scan an online file residing in another server.We need to download the file and upload it in the filterbit server to start scanning for virus.