Fake virus warning on Windows
Are you getting weird messages when trying to download the game? Honestly, don't believe them. It's just the anti-virus program trying to justify its existence and then force us to purchase a certificate (preferably from them) to sign the game with :)
But just to be on the safe side, you can test the game yourself - just download and send it to sites like www.virustotal.com or something similar. It's a good way to be sure.