Complex sentence: The WannaCry ransomware attack is an ongoing worldwide cyberattack by the WannaCry ransomware cryptoworm (also known as WannaCrypt, WanaCrypt0r 2.0, Wanna Decryptor) which targets computers running the Microsoft Windows operating system, encrypting data and demanding ransom payments in the Bitcoin cryptocurrency.
Split into simpler sentences: The WannaCry ransomware attack is an ongoing worldwide cyberattack (also known as WannaCrypt) which targets PC users. The threat runs on the Microsoft Windows OS encrypting all the user data and demanding ransom payments in the Bitcoin cryptocurrency.