Ransomware is a type of malware that impairs the functionality of a computer (for example, by encrypting files on the hard drive), and then demands the victim pay a ransom in order to return their system to normal.
It’s frighteningly common. The term ‘Ransomware’ first entered the Oxford English Dictionary in 2012. We have seen several ugly and dangerous permutations of it, including CryptoLocker, CryptoWall, and most recently, WannaCry.