VirusTotal.com is a file and URL scanner that is a subsidiary of Google. It is totally free. VirusTotal is completely free and does not offer any sort of commercial purpose. So you know that it won’t jack with the answers you need. This is more of a secondary scanner. This is a tool that checks suspicious samples with several antivirus solutions and helps antivirus labs by forwarding them the malware they fail to detect.

I think this is a good service that helps to detect all those nasties out in the world.

Virustotal.com