Geralt_of_Rivia: Microsoft Security Essentials is so notoriously bad that even Microsoft recommends against using it.
I forgot ... i'm on W10 now, there are no more SE, its the upgrade Defender now. And still, it is enough protection, if you know what you are doing. My PC is clean, monthly checks for mal- and adware come clean. My brother always buys the latest and "best" AV software and has to format his hard drive on an anual basis, because he just clicks on everything, opens everything without looking and thinking. Because ... his computer is "protected", isnt it?
So ... back to topic ... the file is good. There were several cases of false alarms with some GOG releases the past few years, this is probably one of them. Just upload the file to Virustotal.com and analyze it. Clearance from Avast, Avira, Kaspersky, Panda and even Eset.