If only 2 AVs find an infection, I would suspect that it is a false positive detection. The only exception would be if the virus infecting the file is very new and the AV fraternity has not had a chance to see it yet. You also have to look at the AVs that are doing the detecting. If a couple of the large AVs spot an infection, like McAfee, Symantec, Microsoft, and Trend Micro, it is probably an infection. Additionally, these AVs have pretty good heuristics/generic detection (but sometimes give false positives): AntiVir (Avira), NOD32, and Sophos. So if only one of the large AVs spot something, but a couple of these also spot it, there is probably an infection.

Submit the file to Threat Expert at https://www.threatexpert.com/submit.aspx on the web. They will actually execute the file and send a report to your email address. Their reports usually include a threat ranking. If it has any rank at all, it is probably malicous. Anubis at https://anubis.iseclab.org/ on the web performs a similar service, but it is sponsored by the academic world, while Threat Expert is in the AV community (PC Tools).

Send any false positives to Clam AV at https://www.clamav.net/sendvirus/ on the web.

Regards,