The WannaCry ransomware attack was a worldwide cyberattack in May 2017 by the WannaCry ransomware cryptoworm, which targeted computers running the Microsoft Windows operating system by encrypting data and demanding ransom payments in the Bitcoin cryptocurrency. - <https://en.wikipedia.org/wiki/WannaCry_ransomware_attack> WannaCry is ransomware that was first seen in a global attack during May 2017, which affected more than 150 countries. It contains worm-like features to spread itself across a computer network using the SMBv1 exploit EternalBlue. - <https://attack.mitre.org/software/S0366/>