The National Cyber Security Centre, part of the GCHQ electronic intelligence agency, said it was working with police and the health system to investigate the attack.
Europol said a special task force at its European Cybercrime Centre was "specially created to assist in such investigations and will play an important role in supporting the investigation".
Experts were scrambling to determine who was behind the attack, which exploited a security flaw in older versions of Microsoft's Windows operating software.
Images appeared on victims' screens demanding payment of $300 (275 euros) in Bitcoin, saying: "Ooops, your files have been encrypted!"
The ransomware is a type of malicious software that infects a computer and restricts users access to it until a ransom is paid to unlock it.
The attack was apparently halted in the afternoon in the United Kingdom when a researcher took control of an Internet domain that acted as a kill switch for the worm's propagation, according to Ars Technica.
"The fact 97% of the NHS trusts and hospitals and doctors are working as normal, so the response has in fact been very good and that's due to the good work of the staff and the resilience that was already put in place".
Some experts say the attackers used a weakness in Microsoft systems which is known to the US National Security Agency as "EternalBlue". "A number of countries and organizations have been affected". A Microsoft spokeswoman said that the company was aware of the reports and was looking into the situation. Microsoft swiftly released software "patches" to fix those holes, but many users still haven't installed updates or still use older versions of Windows.
Among the other victims is a Nissan manufacturing plant in Sunderland, northeast England, though a spokesman said "there has been no major impact on our business".
Renault said it had halted auto production at several sites including Sandouville in northwestern France and Renault-owned Dacia plants in Romania on Saturday to prevent the spread of ransomware in its systems.
Russia's interior ministry said some of its computers had been hit by a "virus attack" and that efforts were underway to destroy it.
Lakeridge Health in Durham Region also reported having intermittent problems with its IT system on Friday.
Germany's national railway said Saturday departure and arrival display screens at its train stations were affected, but there was no impact on actual train services. But U.K. hospitals, Chinese universities and global firms like Fedex also reported they had come under assault.
HOSPITAL chiefs failed to adequately invest in computer security despite a wave of attempted cyber attacks on Scottish health boards, an expert warned last night.
Computers in A&E wards, GP surgeries and other vital services were thought to have been infected with the virus.
In a statement, computer security group Kaspersky Labs said it was "trying to determine whether it is possible to decrypt data locked in the attack - with the aim of developing a decryption tool as soon as possible".
Had it not been for a young cybersecurity researcher's accidental discovery of a so-called "kill switch", the malicious software likely would have spread much farther and faster.
"I highly suspect that, with the amount of coverage that this incident is getting, there are probably already people that are working to incorporate the exploit that was used for spreading", he said.
Avast said the majority of the attacks targeted Russia, Ukraine and Taiwan - though exactly which computers in those areas were targeted remains fuzzy.
Finance chiefs from the Group of Seven rich countries were to commit on Saturday to joining forces to fight the growing threat of worldwide cyberattacks, according to a draft statement of a meeting they are holding in Italy.
G7 finance ministers in their meeting today turned their focus to combating cybercrime, in what Italy's Pier Carlo Padoan described as an "unfortunately very timely" discussion.
It's thought a virus - based on hacking tools developed by USA intelligence agencies - has infected the NHS systems.
While any sized company could be vulnerable, many large organizations with robust security departments would have prioritized the update that Microsoft released in March and wouldn't be vulnerable to Friday's attack.
Flynn is being investigated for taking lobbying payments as a foreign agent while working on Trump's campaign and transition team. Committee member Senator James Lankford (R-Oklahoma) told Fox News that the panel has subpoenaed "a large number of documents".
Trump's communications team has scurried in recent days to explain the president's decision to fire FBI Director James Comey. When the public rightly challenged that fetid story, Trump Thursday admitted that, yes, he had initiated the firing.
As a result, despite their bowling firepower, they have been unable to win games on the bounce and secure their playoff spot. With that, we come down to the last match of the league stage of this year's Indian Premier league.
Arsene Wenger, a target of abuse for much of the season, was even greeted with rapturous applause as he walked toward the fans. Sections of the club's support have called for Wenger, who is yet to announce his future plans, to leave.
One part of the project called the CPEC (the China Pakistan Economic Corridor) runs through Pakistan-Occupied Kashmir or PoK. The event will be attended by key world leaders including 28 heads of state and top officials from more than 60 nations.
Of course, he couldn't hear me, but it felt better to yell anyway. "Honestly, he said he don't know what to say", Harden said. Feeling ill appears to take the blame for him faltering down the stretch in Game 5 and for his Game 6 performance as well.
Oosthuizen and Kim will tee off 10 minutes earlier, while Ian Poulter (-6) and Grillo will start their round at 2:10. There were 74 scores of double-bogey or worse recorded Saturday, and 238 this week.
ABC Entertainment president Channing Dungey said: "American Idol is a pop-culture staple that left the air too soon". TMZ is reporting that the show's inaugural and most successful victor could be returning to the series as a judge.
She nearly had the keys for the Porsche vehicle on offer in Stuttgart in her hands, and has been pretty impressive this week. Mladenovic, seeded 17th, responded by deservedly taking a high quality match the distance by winning a second set tie-break.
The former Manchester City boss has no new injury concerns apart from long-term absentees Ibrahim Afellay and Stephen Ireland. Striker Saido Berahino could start after being an unused substitute on his return from illness last time out.
Portuguese ballad wins Eurovision 2017
In an uncanny coincidence in the wake of Brexit, Britain's Got Talent was scheduled against the BBC broadcast of Eurovision . Salvador Sobral won the 62nd Eurovision Song Contest 2017 with his song " Amar pelos dois " here on Saturday.
Video Proves 8-Year-Old Was Bullied Before Killing Himself
The 10-minute video shows an incident involving a young boy in a bathroom at Carson Elementary School in West Price Hill. As for the school, they claim that they opted to release the surveillance tape in the interest of transparency.
Microsoft shares details on the Windows 10 Fall Creators Update
The big news here was more hardware - namely handheld motion controllers to work with Windows mixed reality for the first time. Specifically, they have released the official name Redstone 3, the next major update or release that will arrive in the fall.
Kelly Ripa's Permanent Co-Host Revealed!
Seacrest will continue to host his nationally syndicated iHeartMedia radio shows and serve as a personality for NBC and E!. A source said of the move: " Live gives the former American Idol host a new daily platform on network television".
Saudi drone downed; troops, mercs killed in Yemen
Violence, starvation and disease have killed more than 10,000 people since the start of the conflict, the United Nations says. Additionally, a unit of the Yemeni military targeted a place of gathering for Saudi mercenaries in Midi Desert.
Donald Trump mum on whether he tapes talks with visitors
Jonah Goldberg offered a different take on the issue in his National Review essay " Why the Trump White House Is So Leaky ". The New York Times reported on Friday that Comey had resisted a request from Trump that he pledge loyalty to the president.