Ransomware is the new type of malware, it can lock your computer or encrypt your files in an effort to get you to pay a ransom, then even if you do pay, there is no guarantee that you will get your files back.
The good news is, there are a lot of companies and people working on this threat and there are now some prevention programs and decryption tools available.
No More Ransom ! is a project by Law enforcement and IT Security companies from around the world that have joined forces to disrupt cybercriminal businesses with ransomware connections.
The project have set up the website No More Ransom with prevention advice and decryption tools etc.