It halted the production lines of a European carmaker and delayed surgical operations in Britain’s National Health Service.
In his first public comments since the attack on Friday, Mr Hunt told Sky News: “Although we have never seen anything on this scale when it comes to ransomware attacks, they are relatively common and there are things that you can do, that everyone can do, all of us can do, to protect ourselves against them”.
Ms Rudd said the National Crime Agency (NCA) and the National Cyber Security Centre (NCSC) were now part of an “international manhunt” to find the perpetrators. “Attackers update their software … other attackers will learn from the method and will carry out attacks”.
Microsoft distributed the patch two months ago, which could have forestalled much of the attack, but in many organizations it was likely lost among the blizzard of updates and patches that large corporations and governments strain to manage. However, officials and security firms said the spread was starting to slow.
WannaCry exploits a vulnerability in older versions of Windows, including Windows 7 and Windows XP.
In a blog post published on Sunday, Brad Smith, Microsoft’s president and chief legal officer, called out the US government for “stockpiling” vulnerabilities, noting that the WannaCry malware used in the attack was stolen from the NSA and published by hackers. Over the weekend, Brad Smith, Microsoft’s chief legal officer, sought to highlight the progress the company has made in beefing up its security, knowing that it’s likely going to be in for some intense scrutiny.
What should I do if my computer has been infected?
Some have also been machines involved in manufacturing or hospital functions, hard to patch without disrupting operations.
Britain’s NHS is the world’s fifth-largest employer after the US and Chinese militaries, Wal-Mart Stores and McDonald’s.
China remained a major source of attack from infected computers, at least during the Asian day, said Michael Gazeley, managing director of Network Box, a Hong Kong-based cybersecurity firm. “It was clear (that) warnings were given to hospital trusts”.
The number of ransomware-affected cases is still rising.
NHS Digital said health trusts across England were sent details of an IT security patch that would have protected them from the attack.
Paying ransom will not ensure any fix, said Eiichi Moriya, a cybersecurity expert and professor at Meiji University.
Affected bodies included a social security department in the city of Changsha, the exit-entry bureau in Dalian, a housing fund in Zhuhai and an industry watchdog in Xuzhou.
Xinhua says the system used by PetroChina’s petrol stations was attacked, meaning customers could not use their cards to pay.
Elsewhere in Asia, the impact seems to have been more limited.
Local media reported that patients arriving at Dharmais Cancer Hospital over t he weekend were unable to get queue numbers and had to wait several hours while staff worked with paper records.
It is not known how the attack has affected GP surgeries, which are due to open as usual on Monday.
The Japan Computer Emergency Response Team Coordination Center, a nonprofit providing support for computer attacks, said 2,000 computers at 600 locations in Japan were reported affected so far.
The full scale of the worldwide cyber attack that continues to disrupt the NHS may only become apparent when people return to work on Monday, experts have warned. By late morning, some people were still filling out forms manually, but the hospital said 70 percent of systems were back online.
Two security firms – Kaspersky Lab and Avast – said Russian Federation was hit hardest. A final fail-safe is to shut down vulnerable systems.