Sometimes there are false positives, most anti-virus programs have a send option to check for this I know when I tried other games it happened, and almost all of them were false positives.
Seems like everything has a virus now. Dont worry, one day soon, all computrons will be infected beyond repair and we will all become the flintstones. XD But no, there isnt any virus. I think th emajority of game soln here are safe. Ive had no issues. =P
From my experience, the anti-virus programs sometimes flag random unknown files found in ZIP files as Trojans just because it doesn't know how to treat it.