WannaCry is a ransomware attack that occurred in May 2017, affecting thousands of computers worldwide. It exploited a vulnerability in the Microsoft Windows operating system, encrypting users' files and demanding payment in Bitcoin to unlock them. The attack disrupted various sectors, including healthcare, transportation, and businesses. The spread of WannaCry was rapid, impacting over 200,000 computers in more than 150 countries. The attack highlighted the importance of cybersecurity and prompted organizations to update their systems and improve their defenses against similar threats. It also led to discussions about the responsibility of software companies in protecting users from vulnerabilities.