VirusTotal is a website created by the Spanish security company Hispasec Sistemas. Launched in June 2004, it was acquired by Google in September 2012. The company’s ownership switched in January 2018 to Chronicle.
VirusTotal aggregates many antivirus products and online scan engines to check for viruses that the user’s own antivirus may have missed, or to verify against any false positives. Files up to 650 MB can be uploaded to the website, or sent via email (max. 32MB). Anti-virus software vendors can receive copies of files that were flagged by other scans but passed by their own engine, to help improve their software and, by extension, VirusTotal’s own capability. Users can also scan suspect URLs and search through the VirusTotal dataset. VirusTotal for dynamic analysis of malware uses the Cuckoo sandbox. VirusTotal was selected by PC World as one of the best 100 products of 2007.
VirusTotal’s Windows Uploader was an application that integrates into the Explorer’s (right-click) contextual menu, listed under Send To > Virus Total. The application also launches manually for submitting a URL or a program that is currently running in the OS.
VirusTotal stores the name and various hashes for each scanned file. Already scanned files can be identified by their known (e.g., VT default) SHA256 hash without uploading complete files. The SHA256 query URL has the form
https://www.virustotal.com/latest-scan/SHA256. File uploads are normally limited to 128 MB. In 2017 VirusTotal discontinued support of the Windows Uploader.
VirusTotal for Browsers
There are several browser extensions available, such as VTzilla for Mozilla Firefox, VTchromizer for Google Chrome and VTexplorer for Internet Explorer. They allow the user to download files directly with VirusTotal’s web application prior to storing them in the computer, as well as scanning URLs.
VirusTotal for Mobile
The service also offers an Android App that employs the public API to search any installed application for VirusTotal’s previously scanned ones and show its status. Any application not previously scanned can be submitted, but an API key must be provided and other restrictions to public API usage may apply (see #Public API).
VirusTotal provides as a free service a public API that allows for automation of some of its online features such as “upload and scan files, submit and scan URLs, access finished scan reports and make automatic comments on URLs and samples”. Some restrictions apply for requests made through the public API, such as requiring an individual API key freely obtained by online signing up, low priority scan queue, limited number of requests per time frame, etc.