Quite often Gamers run into this pertaining to Steam/Minecraft and others. If you feel that the File/Download was Falsely detected. Please follow the guidelines/instructions below my Signature on "How to submit False Artemis!/samples to McAfee Labs.
The Link is HERE
I might add also, upon your submittal you should receive a confirmation that McAfee Labs has it to be analyzed. There will be a Analysis ID # associated with it. Please allow 4-5 buisness days to process.
If not resolved by then, kindly post back the Analysis ID #, and quite possibly we can try and expedite the process.
Wishing all the very Best,