When you just hover your mouse over those highlighted words, it says "link added by VigLink". Wikipedia has information about VigLink here:
https://en.wikipedia.org/wiki/VigLink
From the article, VigLink looks like it's a "in-text advertising and marketing service" that has been added to over 100,000 vBulletin forums and many other sites.
PatriceJ could, and probably will, add more. I don't think it's anything to be concerned over, but better to find out if we're safe than to be sorry (we clicked!).