Weird incident while using Safari. Spyware or something else?

I was using Safari (v. 11.0.3) to look at a Thai restaurant menu on a website I've visited before. When I clicked on the Dinner Menu tab today, however, I ended up at a totally different website. I believe it was financestar.co, with a featured article about the Truthfinder website, among other articles on the page. I don't think I could have ended up at this random site in any other way because the restaurant website doesn't have any ads that I would have inadvertently clicked on, nor have I ever been to the mystery site before. I Googled the site to try and see if it's legitimate but couldn't readily find it. I also noticed that the site did not have a padlock in the url window. And if I try typing the address in directly to go there, I end up at an MSNBC finance site. Weird.

Could this incident be due to something amiss with the Thai restaurant site specifically? Or was there already something lurking on my computer that would warrant the need for me to change my passwords on websites I visit? I'm just puzzled/freaked out as to how I ended up at that other website. I don't download questionable things, click on ads, or do any of the sorts of behaviors I'd expect would make someone susceptible to getting spyware. I think I'm a pretty low-level web surfer, actually. I've already cleared my browser history, deleted my cookies, and emptied the cache. I'm on an iMac 2017, running Sierra v. 10.12.6. Is there anything else I should do? I'd greatly appreciate any insight or advice to calm my extreme anxiety about this!