The latest "Ransomware" was "patched" out some months back, Windows Defender which is part of the windows automatic updates. Not only kills it but vacinates against it.. Of course there will be a new version coming out soon.
However the best "Protion" is between the eyes and fingers... Many Ransomware "Attacks" are launched by a web page.. It has some alarming graphics and some text
WARNING, YOUR COMPUTER IS INFECRTED.. WE HAVE FOUND (random number) OF VIRUS INVEXTRIONS bla bla bla.
I've had to "Crash" out of a few such pages (Force computer shutdown) but follow up scans by multiple anti-malware products came up clean.