Basildon Hospital was not affected by the malware, but as a precaution has taken steps to protect its internal IT systems.
The worm encrypts data on an infected system, and then tells the user that their files have been locked and displays information on how much is to be paid and when - up to roughly $600 in bitcoin.
While the attack that emerged Friday, hitting companies and governments around the world, ebbed in intensity Monday, experts warned that new versions of the virus could emerge.
The WannaCry malware that spread to more than 100 countries in a few hours is throwing up several surprises for cybersecurity researchers, including how it gained its initial foothold, how it spread so fast and why the hackers are not making much money from it. And while Microsoft said it had already released a security update to patch the vulnerability one month earlier, the sequence of events fed speculation that the NSA hadn't told the US tech giant about the security risk until after it had been stolen.
The US National Security Agency (NSA) should shoulder some blame for the attack, which targets vulnerabilities in Microsoft Corp systems and has infected some 30,000 Chinese organisations as of Saturday, the China Daily said.
The worldwide "ransomware" cyber-attack spread to thousands more computers on Monday as people across Asia logged in at work, disrupting businesses, schools, hospitals and daily life.
RBI has asked banks to follow the instructions of government organisation CERT-In to prevent the attack by ransomware, "WannaCry", which has impacted various IT networks in over 150 countries.More news: LaVar Ball ups shoe deal asking price to $3 billion
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"An equivalent scenario with conventional weapons would be the USA military having some of its Tomahawk missiles stolen", Smith said.
"We believe the recent ransomware attack could accelerate the Windows upgrade cycle for enterprises, which would drive further upside to Office 365 Commercial MAUs [monthly active users] beyond what is now factored into our estimates", he added.
"This attack provides yet another example of why the stockpiling of vulnerabilities by governments is such a problem", he said.
Businesses and the public are supposed to constantly update their computers with the latest patches and software updates. Activating the domain worked as a kill switch for the malware.
But not willing to take any chances, ATM management companies are gearing up to update the patches released by Microsoft to beef up protection against malaware. Hardening systems and creating more separation between systems can create additional levels of security, so that if the network is compromised, it doesn't affect every computer or device on that network.
"Therefore I would urge everyone to think twice before clicking on attachments or links from sources that they don't know". The ransomware infects victims by exploiting a Microsoft Windows vulnerability described and fixed in "Microsoft Security Bulletin MS17-010".