VirusTotal
VirusTotal, a subsidiary of Google, is a free online service that analyzes files and URLs enabling the identification of viruses, worms, trojans and other kinds of malicious content detected by antivirus engines and website scanners.
VirusTotal may be used as a means to detect false positives, i.e. innocuous resources detected as malicious by one or more scanners.
VirusTotal's mission is to help in improving the antivirus and security industry and make the internet a safer place through the development of free tools and services.