I have updated the OP with some useful links where is helpful for everybody.
It's good to use an app like RansomFree to protect our PC(s) from ransomwares because it's really dangerous this kind of virus.
I guess it's good that tools like this exist for regular users who are more prone to falling victim to ransomware, but it's quite easy to protect yourself from it without having to use any tools.
1. Don't just download and open files from untrusted sources.
2. Add Noscript and uBlock to your browser and make sure you disable all external plugins like Flash and Java.
By following these simple rules the chances of getting infected should be absolutely minimal.