Guys, try a scan of the tiny file with Virustotal and its ~60 av programs:
https://www.virustotal.com/

Won't be much GOG can do about it*, as it will be the heuristics of the AV program giving a false positive. Heuristics is the prediction algorythm used to identify novel viruses, and it has (inevitably) a pretty dreadful rate of false positives since it is predictive. Which files get flagged is often pretty random and there's no sure fire way to prevent it happening, you can just whitelist it once it happens and if people let the AV know about it then they'll generally whitelist the file or amend the heuristics.

*Software which has had DRM removed is often flagged by heuristics as one of the methods used to remove DRM is similar to a method used to hide viruses in other executable files.

LOL. Somehow I'm not surprised. That definitely sounds like Norton to me. Plus the "antivirus" was harder to uninstall than most viruses would be.

Alrighty guys,
I've updated Win Defender threat definitions this morning.

File now downloads without any warnings. :)