According to some quick research on "Insight network threat":
http://forums.cnet.com/7723-6132_102-501695/norton-says-download-has-insite-network-threat/Someone got the same detection when downloading some game, one that I'm guessing wasn't released by a major commercial publisher (Much like how UFO AI isn't), and simply because the AV company never heard of the game, they automatically flagged it as a problem.
BTW, I've downloaded some builds off this site both before and after the date shown in that pic, I've run scans, and I have not found infections in the installer. It is safe. Actually, it's probably more safe than most typical bloated commercial games, many of which still come packed with all kinds of junk, even when the publisher denies it. I've seen commercial games sold on DVD that have confirmed virus infections, by comparison many of the builds for UFO AI, at least the official releases, are cross-compiled from Linux, last time I checked.
