I was doing a Google search one day a while back for something and one of the hits typically that you get is something like, a site that has pictures of what you are searching for. So I was looking at various pics related to my search, and didn't have an issue until I happened to click on just the right one that was misdirecting me to a nefarious site. Next thing I know, my screen went blank then up popped up that infamous FBI ransomeware!!
Luck for me, I knew exactly what to do from there.
I unplugged my computer and did a hard re-boot into safe mode. I then did a system restore to an earlier time frame and I was back in business. Just to be sure, I updated all of my antimalware/anitvirus stuff and did a complete and thorough search to make sure it was all gone.
All I can say is, thinking about this in hindsight, I should have looked at the part down below that tells me the site's address. You see, when you hover over a link, down below on your browser it will show you the website's address. If it looks questionable, don't click on it!
That's the best advice I can give since it doesn't seem to matter if you have or what you have in place as anti malware. I was running Malwarebytes along with Zonealarm fully updated when this happened to me. So your first line of defense is
Look Before You Leap.