Microsoft has warned that nearly one million computers globally are still at risk of malware attack similar to WannaCry that spread worldwide in 2017 causing billions of dollars in damage.
The software giant recently discovered "wormable" vulnerability in Remote Desktop Services for Windows that can automatically spread.
The company has issued its second advisory, urging users to update their systems to prevent the "BlueKeep" malware attack, TechCrunch reported on Friday.
"Microsoft is confident that an exploit exists for this vulnerability. It's been only two weeks since the fix was released and there has been no sign of a worm yet. This does not mean that we're out of the woods," warned Simon Pope, director of incident response at Microsoft's Security Response Center (MSRC).
"Our recommendation remains the same. We strongly advise that all affected systems should be updated as soon as possible," said Microsoft.
The bug is a "critical" vulnerability that affects computers running Windows XP, Windows 7 and server operating systems.