This weekend, a ransomware virus called WannaCry attacked Windows systems around the world. In a ransomware attack, a user’s files are encrypted and the attacker demands money to unlock them. The WannaCry attack spread quickly, infecting more than 70,000 machines in hospitals, schools, banks, government offices, and companies. Unlike other ransomware viruses, which are typically spread by clicking an infected link, WannaCry took advantage of a security flaw in older Windows XP and Windows 8 software. A 22-year-old cyber security researcher in England helped to slow the attack, but experts say the cyberattacks will continue. If you’re running a computer with Windows, you should update your software immediately.