President Vladimir Putin denied Russian Federation, which has been accused of cyber meddling in several countries around the world in recent years, had anything to do with an attack that hit hundreds of thousands of computers. By mid-day Sunday, some 20% of the stations were still disconnected from the Internet, but efforts were continuing to restore payment options, the company said in a statement. Expensive, specialist equipment may not work with newer operating systems, or require whole new software to be written to enable compatibility.
Smith wrote in a blog post Sunday that the attack is an excellent object lesson in why governments stockpiling such vulnerabilities is such a problem.
"We have seen vulnerabilities stored by the Central Intelligence Agency show up on WikiLeaks, and now this vulnerability stolen from the NSA has affected customers around the world", wrote Smith.
"The governments of the world should treat this attack as a wake up call".
But global fears eased on Monday as the number of incidents reported levelled off.
Organizations are scrambling to apply the latest security patch to their computers to prevent the spread of the attack. In light of the attacks, it would seem that time has come.
A top Microsoft exec criticized at the US and other governments who hoard software exploits in the wake of the massive global infection by WannaCry ransomware as the company struggled to deal with the fallout from the hundreds of thousands of unpatched computers affected, for the first time offering free patches for older software products it long ago stopped supporting.
USA package delivery giant FedEx, Spanish telecoms giant Telefonica and Germany's Deutsche Bahn rail network were among those hit in the attacks, which demanded money to allow users to unblock their computers.
"It's a laudable goal", he said of the Microsoft call, "But we all know some countries would sign-up and then secretly violate it".
The NCA urged victims of attacks not to pay any ransom, saying there was no guarantee that encrypted files would be restored. After three days, the demand is hiked to $600 and after seven days, files will supposedly be deleted.
Experts and governments alike warn against ceding to the demands and Wainwright said few victims so far had been paying up.
The culprits used a digital code believed to have been developed by the US NSA - and subsequently leaked as part of a document dump, according to researchers at the Moscow-based computer security firm Kaspersky Lab. Shadow Brokers, a group that regularly posts stolen software and hacking tools developed by the USA government, released the tool online last month. "WannaCry" is particularly malicious because it takes just one person to click on an infected link or email attachment to cause the virus to spread to other machines on the same network.
Anti-virus experts Symantec said the majority of organisations affected were in Europe.
Senior US security officials held another meeting in the White House Situation Room on Saturday, and the Federal Bureau of Investigation and the NSA were working to help mitigate damage and identify the perpetrators of the massive cyber attack, said the official, who spoke on condition of anonymity to discuss internal deliberations.
Debbie Galloway, one of the managers at the practice, said: "Because we can not access anybody's medical records, it is unsafe".