Cryptolocker ransomeware type of viruses go by the names of FBI virus, CBT locker, cryptowall, crowti, Teslacrypt, nymaim and others. They basically try to get you to give them money so that you can access your computer and files again.
There is a program called CryptoPrevent you can install on your computer to help prevent ransomware type of virus infections. It does not remove the virus on your computer and your computer must currently be free of viruses. First run a virus scan on your computer then download and install the program. When the program opens up select default and click apply. The free version does not update itself so you have to check for updates manually as shown in the picture below. The paid version provides automatic updates.
You can download the program from the company’s website at