Virustotal is a small application designed to do hash searchs of scanner results on the virustotal web site. It can be run in single file search mode, or bulk hash lookup mode. It is integrated with the features in shellext.exe. When you register the shell extensions with shellext, it will add a right click menu item in explorer for all files "VirusTotal". Additionally, when using the "Hash Files" shell menu item from explorer, there is a menu item to in HashFiles form to Virustotal lookup on ALL which willrun it in bulk lookup mode. The executable can also be run directly using its command line switches or just by double clicking on it and then loading a md5 hash list from the clipboard by right clicking on the main form. See source for more specific details. Since the Virustotal public API has a max request interval of 4 seconds between requests, this application also contains a cache feature where reports can be cached to disk for immediate results if you find you end up looking up the results several times. As per the Virustotal license agreement, their Virusscan results can not be used in a commercial context and is for individual research only.