I might add in addition, that after performing a 'Site Review' McAfee Web Advisor gave it a 'Minimal Risk' Rating.
http://www.mcafee.com/threat-intelligence/site/default.aspx?url=https://www.factorio.com/demo/stable Having said this, it could be also due to the 'Unpacker' of the (.Exe) and also being associated with 'Steam' applications.
Which are notorious for being detected by McAfee. On the brighter side of the equation, in most cases results in it being 'Whitelisted/Suppressed'.
All the Best,
Could you kindly provide me the Analysis ID# you should have received with your submission. I can then escalate your issue on your behalf.