What is WannaCry Ransomware?

WannaCry (also referred to as WCry, WanaCrypt0r, and Wana Decrypt0r 2.0.) was a ransomware worm deployed in 2017 that targeted vulnerabilities in the Windows operating system, encrypted files on infected devices' hard drives, and demanded a ransom payment in bitcoin (BTC) in order to decrypt the files. The malware rapidly spread through multiple computer networks and impacted users in over 150 countries, resulting in billions of dollars worth of damages and ransom payments.