I am usiing Kaspersky Internet protection. I keep getting a 403 error Virus Detected on just one of the files that I am trying to convert. What do I need to do.

I am getting a message 403 that the file that I am trying to convert has a virus.  I use Kaspersky virus detection and I ran it on just that file.  I have converted another file with on problems.  What do I need to do?