Nothing on GOG has a virus.

Thankfully none transferrable over the internets.

GOG have no virus that I've ever heard of no but they DO use cracks to get rid of the DRM. Most antivirus programs think cracks are viruses because of how they work so if you buy another GOG game (Buy buy BUY!) and get alerts don't panic, it's most likely the crack.

I'm thinking you have your antivirus program set to a high security level and automatic responses to alerts, which is a sure way to really mess up your system so your antivirus program ran haywire.

My antivirus still thinks that Patrician 3 has a trojan in it :)