We get occasional reports about players saying to developers that games are being detected as a virus by their chosen antivirus product when they download and install the game.
It's worth stating 100% just now that there is not a virus in the GMS2 runtime and the detection is a false-positive. We cannot guarantee the behaviour of third-party extensions as to whether they contain something malicious, but then you should already know if your own project contains a dodgy extension or not.
Unfortunately, this is not something we can fix, as it's your final compiled game exe which is being reported as an issue, and so it's up to you to work with the AV provider in question to update their records and stop the message being shown to new players when they install.
There are two routes to doing this. One free and easy, but slow and requires redoing when you release new versions; one definitely not cheap and not initially easy, but then stops the issue much more quickly and for all versions going forward.
We would also suggest you recommend to these users that they allow a short amount of time between downloading an installer and trying to run it, to ensure that the AV client has finished its initial scan of the product and so doesn't go into high alert because a file was downloaded and then immediately ran.
Route 1: Submit the exe to the AV provider when asked, then wait
The easy option is to reassure your players that this is a false-positive and that they should submit the file(s) to their antivirus provider via its submission process so the provider can analyse the executable properly, then they can simply restore the file(s) from the quarantine and play the game.
If the AV client definitely deleted the files, rather than quarantined, they can try reinstalling and responding to any security prompts from the AV during the new installation so that the AV client leaves the files alone.
Unfortunately, this process would have to be repeated for each AV client which flags the executable as an issue, so you might need to advise a number of customers to do this (the more who submit, the better...). Also, depending on how quickly you push out new releases, it may have to be repeated a few times before the AV provider's analysis is completed and their detection database is updated and released to these users.
Route 2: Codesign your executables before you release them
The real fix for this issue is to obtain a codesigning certificate from a verification service, such as the ones below:
Other providers are available if you Google "codesigning certificate", which one you choose is entirely up to you, they are not ranked in this list, and we don't recommend a specific provider.
You make your exe as per normal using GMS2 and then follow the signing entities process for "wrapping" the installer/game exe with their signing setup before you actually publish the release to your chosen stores. (This process can vary by provider and will change when they see fit to update their process, so we can't document here.)
This route will straight away stop Windows Smartscreen dialogs from appearing and avoid Chrome messages about not running downloaded exes from your Downloads folder, and then should stop the AV client false-positives pretty rapidly also. Note, however, in order to provide this facility you typically need something higher than the cheapest certificate on offer from the providers listed above.
Furthermore, if a user has an issue because they got your game from an untrusted source and the file has actually been tampered with, you immediately know there is potentially a legitimate issue and can suggest they should delete the file and download it again from a safe source.