I got a copy about 1 year ago but never managed to play it :/

Honestly I'd just put a "use at your own risk - some people reported some positives" and leave the download here :/

If we are talking about Windows here, it will "flag" any unsigned exe downloaded from the internet, as potentially malicious.

That being said, there are ways around it.
You can wrap it in an installer. and sign yourself as a developer. Or try to make your players to use itch launcher as it voids this issue.

But if some antivirus software is flagging it as malware that is a completely different animal and I do not know much about it.

They are most definitely false positives, but it's still good that you're taking the initiative to make sure everything's in order. From what I remember, my own Gamemaker games were flagged by certain antiviruses, just because they were standalone .exe files that were unknown to the antivirus' malicious software database.