Sorry for the poor phrasing of the title but I'm not sure what exactly I'm dealing with here.
I searched something on Google and clicked on a result which I know for sure is the correct website I wanted to visit.
Instead of being redirected to the website (a quite big Payment Service Provider, so 100% legit) I was redirected to a fake Google website claiming that my IP has been chosen for a reward for my Google membership (screenshot below). My ISP and my City were also mentioned in the text, but that's not all too hard to derive from the IP I guess.
I could not reprocuce this behaviour and the fake website is not reachable anymore (it was for only 10 minutes or so).
I've seen something like this a few times before on mobile but I always thought that it was just a typo or something. But this was the first time this happened on my desktop machine (latest Firefox, Ubuntu 18.04, powerline-wired home network).
What exactly is this and how does that happen? Should I be worried?