That's very unlikely. Every single file on this website is individually opened and scanned by the admins before being hosted. I suspect that this aircraft contains some C gauge code which the scanner is mistakenly picking up as a virus.
I have a web design program, no less, which sometimes gets picked up by the virus checker because of one bit of code in it. I've even had my own code flagged before!
I fly through the valley of death, but I fear no evil,for I am at 80,000 feet and climbing. Let's powerdive and scare that poor soul in that Ultralight there.