I know.. As I said they likely get flagged, because of the ads that pop-up. Your browser doesn't actually check for viruses. it just checks urls and if one of the url is flagged it will give you those warnings.The fact that it only happens on Viking is more than a little suspicious. Happened for both this game and a different game yesterday. Chrome blocks the download from Viking, works fine from the other sites.
Feel feel to ignore and do your own thing. I downloaded it from there fine, and it didn't contain any viruses.