A cybersecurity researcher has been credited with slowing the ransomware after accidentally discovering a "kill switch" that could prevent the spread.
The Guardian newspaper reported Saturday that the 22-year-old Britain-based researcher, identified online only as MalwareTech, found that the software's spread could be stopped by registering a garbled domain name.
"The problems continue after Hospitals%2C+Schools%2C+And+Companies+Worldwide" the big cyber attack which affected dozens of countries, according to Nova Tv.
The paper quoted the researcher as saying: "This is not over".
Defence minister Michael Fallon told the BBC the government under Prime Minister Theresa May was spending around 50 million pounds on improving the computer systems in the NHS after warning the service that it needed to reduce its exposure to "the weakest system, the Windows XP".
The threat was "escalating" as cyber experts warned that another attack was imminent in coming days, he said.
The widescale attack involved ransomware, in which infiltrated computers are held hostage until a ransom is paid, in conjunction with "a worm functionality" that automatically spread the virus across global networks. It crippled the British health care system for a day, infecting almost 20 percent of its health care groups, forcing medical treatments to be canceled or postponed for thousands of people.
It is feared more cases of the "Wannacry" cyber attack will be uncovered in Ireland as businesses re-open tomorrow.
Now that this "WannaCry" malware is out there, the world's computer systems are vulnerable to a degree they haven't been before, unless people everywhere move quickly to install Microsoft's security patches.
The wave of cyber attacks wreaking havoc cross the globe is "at an unprecedented level", the European Union's law enforcement agency Europol has said.
"The numbers are going up, I am anxious about how the numbers will continue to grow when people go to work and turn (on) their machines on Monday morning", Europol Director Rob Wainwright said.
Among the countries that reported major problems were Slovenia, which said French vehicle manufacturer Renault's assembly plant in Slovenia halted production after it was targeted in the global cyber-attack.
France's carmaker Renault was forced to stop production at a number of sites.
Those attacks require a serious global investigation for identifying the hackers, pointed also the Agency.
This is already believed to be the biggest online extortion attack ever recorded, disrupting computers that run factories, banks, government agencies and transport systems in nations as diverse as Russia, Ukraine, Brazil, Spain, India and the U.S.
Deutsche Bahn: The German railway company told CNNMoney that due to the attack "passenger information displays in some stations were inoperative" as were "some ticket machines". Omer Fatih Sayan said the country's cyber security centre was continuing operations against the malicious software.
"Do not open emails from unknown sources or containing suspicious links or attachments". The company said the virus has been localized and "technical work is underway to destroy it and update the antivirus protection".
British Home Secretary Amber Rudd said Saturday that 45 public health organizations were hit, but she stressed that no patient data had been stolen.
By then the "ransomware" attack had crippled Britain's hospital network and computer systems in several countries in an effort to extort money from computer users.