16 U.K. organizations have been affected by the ongoing WannaCry attack, including the National Health Service (NHS), which was forced to reject patients, cancel operations, and reschedule appointments due to malware infection. Microsoft just released an emergency security patch for all unsupported version of Windows Windows, including Windows XP, Vista, Server 2003 or 2008. Users are strongly advised to follow prevention measures in order to protect themselves, such as enabling firewall and disabling SMB (SMB) Antivirus software up-to-date.
Source: https://thehackernews.com/2017/05/wannacry-ransomware-windows.html