A ransomware attack called WannaCry, also known as WanaCrypt0r 2.0, was launched on May 12, 2017, which exploited exposure in Windows operating systems and demanded $300 worth of Bitcoin from users to release important files. This attack affected over 100 countries worldwide, with nearly 1,000 PCs influenced. The paper discusses the prevention measures that can be taken by companies to prevent such attacks, including keeping backups of essential data, not opening spam emails, restricting website access, and using antivirus software.