Tried using the contact us option, which forced the useless chat bot on to me.
After taking a few failed attempts to get the right direction.
I went through the options to report a virus issue with a game [Eador Imperium].
At the very end the bot was stated it can't make a ticket after having excepted everything up till the very end.

The virus reports I kept getting were during the installation of "Eador Imperium" using GOG galaxy [up to date, fresh install today].
OS: Windows 10[64-bit]
Only using windows defender [Used to use Paid stuff, but never helped]

windows defender pinged the issue for 2 hours to I returned [bout 15 times]
"Trojan:Script/Wacatac.B!ml" was is each report

Also note, I have installed and played the game in the past, with out these alert popping [though I was using trend micro at the time]

Step 1: Uninstall any antivirus programme that reports any game from GOG contains any malicious code.

Step 2: There is no step 2.

You can bypass the chatbot with a user style. Supposedly e-mailing support (at) gog.com also works, though I've never tried this.
In all likelihood, you'll have to wait weeks for a response, after which you'll be told the report has been passed on to the relevant team, and that will be the end of it.

A more productive use of your time would be to contact Snowbird Games directly, and to report a suspected false positive in Windows Defender. If I'm not mistaken, Microsoft Security Intelligence is where to do that.
Bear in mind that earlier this year, Microsoft Defender identified Microsoft Office updates as ransomware, so don't ignore such warnings outright, but take them with a grain of salt and maybe seek a second opinion on VirusTotal.

The odds are in favor of it not being a virus, but rather a false positive issue with your AV program.

But if in any doubt, you can try VirusTotal, which is the best place to check for false positive with a file.

https://www.virustotal.com/gui/

P.S. The biggest clue to a false positive though, is the lack of other GOG customers doing a thread like yours.

P.S.S. It is also possible some virus got onto your PC and infected that file.