Virustotal is a service that analyzes suspicious files and URLs and facilitates the quick detection of viruses, worms, trojans, and all kinds of malware detected by antivirus engines. More information...
This module integrates the VirusTotal API service
It provides an API for developers and Rules 2.x integration
(but does nothing out of the box).
Goto admin/config/system/virustotal and paste in a valid personal API key. If you are registered to the VirusTotal community you will find you key at your profile on the "API key" tab.
Sitebuilding(7.x)
If you just need the basic API functionality you should have a look at the VirusTotal Rules submodule. With Rules 2.x and the VirusTotal API Rules integration you can handle most of the API functionality without writing any line of code. Instructions..