I had one of those a while back. It locked me up and popped up a window telling me the FBI had locked my files, but I could unlock it by either taking my computer to Walmart and paying $100 or entering my credit card number and paying online. It also “warned” me that attempting to unlock my computer any other way is a FELONY, and I would be subject to Federal prosecution if I did so. I have Mrs. Hugin set up as a separate user, (both of us admins) so I rebooted, logged in as her and everything worked on her account. So I deleted myself as a user, and set myself up with a slightly different name. No problems since, though I did lose all my saved files that weren’t backed up.
BTW, I have up to date Norton and it didn’t stop the attack.
Norton sucks, go with the free version of avast or avg
Download Hitman Pro and install it... get yourself a thumbdrive and create a boot drive on it with Hitman... search Youtube there is a good walkthrough there with a guy with a European accent... it is the only thing I have used to get rid of these “FBI” ransomware worms.