I've recently joined a team which worked back in 2008-2009 in a game project. The game is still running, however, it's detected by few antivirus providers as a malware. At first I thought sending them an email asking for the reason it got detected would've been the best thing to do, but gmail won't allow me to upload the file since it also detects it as malware. I even tried to send a zipped archive with the app in it but it hasn't changed anything. Does anyone have a suggestion on what to do? I just want to identify the reason why the application gets detected to check whether the game is a virus or a false positive, and in this case edit the code (which I have at disposal, but note that it's very confusing since it's an old software). Thank you for your time.
Edit: Uploaded a screenshot of the scan with virustotal.com.