Alright, if you are worrying about it, you may not to play this game. Nobody force you to download the game.
Viewing post in Deer At The Table: DEMO comments
just to clarify: According to tests, it seems like such problem only appears on a very small % of users (personally I and my friends who was testing and downloading the game did not get such messages from their browsers and anti-viruses), and according to this, I am not able to find the problem of such messages. I also tested the file on my anti-virus, and it does not detect the file as a virus.