So, I don’t have to explain what ransomware is…
Download this fella, install it (it’ll appear in the systray). Click on the green wheel to cofigure the program’s general settings. Then click on the “Immunization” slider and turn it to the “On” position. Done.
So…what does it do? It does not allow executable files from %appdata% and %startup% to run.
Your computer will now be protected against CryptoWall and CTB-Locker ransomware.
Other steps to take against ransomeware: here.
Download site for Anti-Ransomeware (CryptoWall Vaccine): here.
Source:
http://www.thewindowsclub.com/bitdefender-anti-ransomware-windows