Trojan.Gen.2

I did full system scan and fond "Trojan.Gen.2" located in my download. I have Norton Internet Security 5 for Mac ver. 5.7 (25) the file is quarantine. I've also read the this virus only affects PCs so why is it in quarantine and how can I remove the file completely from my Mac. I need some specific instruction on how to remove this from my machine.