The WannaCry ransomware attack was a worldwide cyberattack on May 2017 caused by the WannaCry[a] ransomware cryptoworm, which targeted computers running Microsoft Windows operating system by encrypting data and demanding ransom payments in Bitcoin cryptocurrency. WannaCry propagates using an exploit of Windows' Server Message Block (SMB) protocol. To date, Nokia has not observed a significant increase in this exploit in networks protected by NetGuard Endpoint Security (NES). Nokia will continue to monitor the situation and update customers as appropriate.