Ransomware is new and advance kind of malware that lock down your computer and encrypt every piece of data or may be in chunk(depends on the coding) and ask some ransom amount to unlock it.once the victim pay the ransom he/she will get the decryption key and pc will be unlocked.ransomware is spread through a computer worm that enters through an email or network vulnerability so it is advisable to take regular backup and store it into multiple devices