9 out of 10 viruses are never viruses, but are just mistakes that the anti-virus software "thinks" its located. Dont even get me started on those pesky popups that state "we have scanned your system and detected 40 million viruses...buy our software and your system will be clean" - those popups always make me laugh :)
I very much doubt that your website has any viruses, im just assuming this. I think its simply the virus protection software scanning a certain file, not knowing what it does and assumes its a virues.
The test to do, is to try accessing same website on a different computer that is not using the same anti-virus software that you are using (just to determine if its your version of the anti-virus software).