"WannaCry is ransomware that contains a worm component. It attempts to exploit vulnerabilities in the Windows SMBv1 server to remotely compromise systems, encrypt files, and spread to other hosts. Systems that have installed the MS17-010 patch are not vulnerable to the exploits used. Patches to address the vulnerabilities identified in Microsoft Security Bulletin MS17-010 are available for all versions of Windows from XP onward."
Industrial Control Systems Cyber Emergency Response Team (ICS-CERT): https://ics-cert.us-cert.gov/