As far as I’m aware, there is some automated testing being done when someone uploads a new project, that makes sure they are not uploading something malicious. I’m not sure if this was the case a few years back.
Very often, a game is mistakenly flagged as “malicious” by an antivirus. This is a known issue in the indie game dev community. If a project is fairly popular, I’d say it should be for the most part safe.
Hope that helps :)