WannaCry ransomware attack

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 form of bitcoin cryptocurrency. It was propagated using EternalBlue, an exploit developed by the United States National Security Agency (NSA) for Microsoft Windows systems.

Source: Wikipedia — WannaCry ransomware attack (CC BY-SA 4.0)