I can assure you it is not a virus because I would never put everything out harm someone's computer. Also sometimes with some computer browsers it can be really strict of the certain thing you download on the internet especially if it's a website that you never been on. If you want to download the game you might have to change your browser settings and also I made this game in Windows so I'm not sure if you have a Mac or Linux but that can also be a reason why it says that as well again not this me speculating because I don't use a Mac or Linux. Again I hope this helps you and U hope you have a Good Day MegaGamer2008!