Cyber security experts rushed to restore systems on Saturday after an unprecedented global wave of cyberattacks that struck targets ranging from Russia's banks to British hospitals and a French carmaker's factories.

The hunt was on for the culprits behind the assault, which was being described as the biggest cyber ransom attack ever.

State agencies and major companies around the world were left reeling by the attacks which blocked access to files and demanded ransom money, forcing them to shut down their computer systems.

"The recent attack is at an unprecedented level and will require a complex international investigation to identify the culprits," said Europol, Europe's policing agency.

The attacks, which experts said affected dozens of countries, used a technique known as ransomware that locks users' files unless they pay the attackers a designated sum in the virtual Bitcoin currency.

Mikko Hypponen, chief research officer at the Helsinki-based cyber security company F-Secure, told AFP that the attack was "the biggest ransomware outbreak in history", saying that 130,000 systems in more than 100 countries had been affected.

He said that Russia and India were hit particularly hard, in large part because the older Windows XP operating software is still widely used in the countries.

The attacks apparently exploited a flaw exposed in documents leaked from the US National Security Agency (NSA).

The attacks hit a whole range of organisations and businesses worldwide.

French carmaker Renault was forced to stop production at sites in France and Slovenia, saying the measure was aimed at stopping the virus from spreading.

In the United States, package delivery group FedEx acknowledged it had been hit by malware and said it was "implementing remediation steps as quickly as possible."

Russia's interior ministry said that some of its computers had been hit by a "virus attack" and that efforts were underway to destroy it.

The country's central bank said the banking system was hit, and the railway system also reported attempted breaches.

The central bank's IT attack monitoring centre "detected mass distribution of harmful software" but no "instances of compromise", it said.

Russia's largest bank Sberbank said its systems "detected in time attempts to penetrate bank infrastructure".

Germany's Deutsche Bahn computers were also impacted, with the rail operator reporting that station display panels were affected.

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."

On Saturday, a cyber security researcher told AFP he had accidentally discovered a "kill switch" that could prevent the spread of the ransomware.

The researcher, tweeting as @MalwareTechBlog, said that the discovery was accidental, but that registering a domain name used by the malware stops it from spreading. Computers already affected will not be helped by the solution.

But @MalwareTechBlog warned that the "crisis isn't over" as those behind it "can always change the code and try again".

The malware's name is WCry, but analysts were also using variants such as WannaCry.

Britain's National Cyber Security Centre and its National Crime Agency were looking into the UK incidents, which disrupted care at National Health Service facilities, forcing ambulances to divert and hospitals to postpone operations.

Pictures on social media showed screens of NHS computers with images demanding payment of $300 (230 pounds, 275 euros) in Bitcoin, saying: "Ooops, your files have been encrypted!"

It demands payment in three days or the price is doubled, and if none is received in seven days the files will be deleted, according to the screen message.

"Ransomware becomes particularly nasty when it infects institutions like hospitals, where it can put people's lives in danger," said Kroustek, the Avast analyst.

A hacking group called Shadow Brokers released the malware in April claiming to have discovered the flaw from the NSA, Kaspersky said.

Although Microsoft released a security patch for the flaw earlier this year, many systems have yet to be updated, researchers said.

"Unlike most other attacks, this malware is spreading primarily by direct infection from machine to machine on local networks, rather than purely by email," said Lance Cottrell, chief scientist at the US technology group Ntrepid.

Some said the attacks highlighted the need for agencies like the NSA to disclose security flaws so they can be patched.

G7 finance ministers meeting in Italy discussed the attacks and were expected to commit to stepping up international cooperation against a growing threat to their economies.</s>Users of old Windows systems can now download a patch to protect them from this week’s massive ransomware attack.

In a rare step, Microsoft published a patch for Windows XP, Windows Server 2003 and Windows 8 -- all of them operating systems for which it no longer provides mainstream support.

Users can download and find more information about the patches in Microsoft’s blog post about Friday’s attack from the WannaCry ransomware.

The ransomware, which has spread globally, has been infecting computers by exploiting a Windows vulnerability involving the Server Message Block protocol, a file-sharing feature.

Computers infected with WannaCry will have their data encrypted, and display a ransom note demanding $300 or $600 in bitcoin to free the files.

Fortunately, Windows 10 customers were not targeted in Friday’s attack. In March, Microsoft patched the vulnerability that the ransomware exploits -- but only for newer Windows systems. That’s left older Windows machines, or those users who failed to patch newer machines, vulnerable to Friday’s attack.

The ransomware was initially found spreading through attachments in email phishing campaigns. In certain cases, the scam emails pretended to represent a bank alert about a money transfer, according to Cisco’s Talos security group.

Users can protect themselves by being careful about such emails, Microsoft said. The company’s free antivirus software Windows Defender, along with other third-party security products from those including Kaspersky Lab and Avast, will also detect and remove the threat.

Once a vulnerable PC becomes infected, the computer will attempt to spread to other machines over the local network as well as over the internet. The ransomware will specifically scan for unpatched machines that have the Server Message Block vulnerability exposed.

Businesses can prevent this by disabling the Server Message Block protocol in vulnerable PCs. They can also use a firewall to block unrecognized internet traffic from accessing the networking ports the Server Message Block uses.

Fortunately, Friday’s ransomware attack may have been contained. A security researcher who goes by the name MalwareTech has activated a sort of kill-switch in WannaCry that stops it from spreading.

As a result, over 100,000 new infections were prevented, according to U.K.’s National Cyber Security Centre. But experts also warn that WannaCry’s developers may be working on other versions that won’t be easy to disable.

“It's very important everyone understands that all they (the hackers) need to do is change some code and start again. Patch your systems now!” MalwareTech tweeted.

Unfortunately, the kill-switch’s activation will provide no relief to existing victims. The ransomware will persist on systems already infected.

Friday’s ransomware attack appears to have spread mainly in Europe and Asia, with Russia among those nations hardest hit, according to security researchers.

Security experts are advising victims to wait before paying the ransom. It's possible that researchers will develop a free solution that can remove the infection.</s>World reels from massive cyberattack that hit nearly 100 countries

HONG KONG (CNNMoney) — Organizations around the world were digging out this weekend from what experts are calling one of the biggest cyberattacks ever.

Hospitals, major companies and government offices were hit by a virus that seeks to seize control of computers until the victims pay a ransom.

Cybersecurity firm Avast said it had identified more than 75,000 ransomware attacks in 99 countries on Friday, making it one of the broadest and most damaging cyberattacks in history.

Avast said the majority of the attacks targeted Russia, Ukraine and Taiwan. But U.K. hospitals, Chinese universities and global firms like Fedex also reported they had come under assault.

Security experts said the spread of the ransomware had been inadvertently stopped late Friday. The ransomware was designed to repeatedly contact an unregistered domain in its code. A 22-year-old security researcher in the U.K, who goes by MalwareTech, registered that domain to analyze the attack, but it turned out the ransomware needed it to remain unregistered to keep spreading.

“Thus by registering it we inadvertently stopped any subsequent infections,” he told CNNTech.

However, a hacker could change the code to remove the domain and try the ransomware attack again.

It remained unclear how many organizations had already lost control of their data to the malicious software — and researchers warned that copycat attacks could follow.

Europol said Saturday that the attack was of an “unprecedented level and requires international investigation.” And the U.K. government called an emergency meeting over the crisis.

U.S. Treasury Secretary Steven Mnuchin, at a meeting of world leaders in Italy, said the attack was a reminder of the importance of cybersecurity. “It’s a big priority of mine that we protect the financial infrastructure,” he said.

The ransomware, called WannaCry, locks down all the files on an infected computer and asks the computer’s administrator to pay in order to regain control of them. The exploit was leaked last month as part of a trove of NSA spy tools.

The ransomware is spread by taking advantage of a Windows vulnerability that Microsoft released a security patch for in March. But computers and networks that hadn’t updated their systems were still at risk.

In the wake of the attack, Microsoft said it had taken the “highly unusual step” of releasing a patch for computers running older operating systems including Windows XP, Windows 8 and Windows Server 2003.

But the patches won’t do any good for machines that have already been hit.

“Affected machines have six hours to pay up and every few hours the ransom goes up,” said Kurt Baumgartner, the principal security researcher at security firm Kaspersky Lab. “Most folks that have paid up appear to have paid the initial $300 in the first few hours.”

On Saturday, experts said it appeared that the ransomware had made just over $20,000, although they expected that number to pop when people went back into the office Monday.

WannaCry has already caused massive disruption around the globe.

Sixteen National Health Service organizations in the UK were hit, and some of those hospitals canceled outpatient appointments and told people to avoid emergency departments if possible. The NHS said in a statement on Saturday that there was no evidence that patient information had been compromised.

In China, the internet security company Qihoo360 issued a “red alert” saying that a large number of colleges and students in the country had been affected by the ransomware, which is also referred to as WannaCrypt. State media reported that digital payment systems at PetroChina gas stations were offline, forcing customers to pay cash.

Major global companies said they also came under attack.

Fedex said Friday it was “experiencing interference with some of our Windows-based systems caused by malware” and was trying to fix the problems as quickly as possible. Two big telecom companies, Telefónica of Spain and Megafon of Russia, were also hit.

“This is turning into the biggest cybersecurity incident I’ve ever seen,” U.K.-based security architect Kevin Beaumont said.

Russia’s Interior Ministry released a statement Friday acknowledging a ransomware attack on its computers, adding that less than 1% of computers were affected, and that the virus was now “localized” and being destroyed.

The U.S. Department of Homeland Security, in a statement late Friday, encouraged people to update their operating systems. “We are actively sharing information related to this event and stand ready to lend technical support and assistance as needed to our partners, both in the United States and internationally,” the department said.

According to Matthew Hickey, founder of the security firm Hacker House, the attack is not surprising, and it shows many organizations do not apply updates in a timely fashion.

When CNNTech first reported the Microsoft vulnerabilities leaked in April, Hickey said they were the “most damaging” he’d seen in several years, and warned that businesses would be most at risk.

Consumers who have up-to-date software are protected from this ransomware. Here’s how to turn automatic updates on.

It’s not the first time hackers have used the leaked NSA tools to infect computers. Soon after the leak, hackers infected thousands of vulnerable machines with a backdoor called DOUBLEPULSAR.

— Donna Borak, Samuel Burke, Paul K. Murphy, Mariano Castillo, Jessica King, Yuli Yang, Steven Jiang, Clare Sebastian and Livvy Doherty contributed to this report.</s>Media playback is unsupported on your device Media caption The ransomware involved has been defeated before, reports the BBC's Chris Foxx

NHS services across England and Scotland have been hit by a large-scale cyber-attack that has disrupted hospital and GP appointments.

The prime minister said the incident was part of an untargeted wider attack affecting organisations globally.

Some hospitals and GPs have been unable to access patient data, after their computers were locked by a ransomware program demanding a payment worth £230.

But there is no evidence patient data has been compromised, NHS Digital said.

The BBC understands about 40 NHS organisations and some GP practices have been hit. The NHS in Wales and Northern Ireland has not been affected.

There is no indication of who is behind the attack yet, but the hackers demanded their payment in the virtual currency Bitcoin, which is harder to trace.

Prime Minister Theresa May said: "This is not targeted at the NHS, it's an international attack and a number of countries and organisations have been affected."

Ambulances diverted

Mrs May added that the National Cyber Security Centre (NCSC) was "working closely" with the NHS "to ensure that they support the organisations concerned and that they protect patient safety".

Ambulances have been diverted from hospitals in some areas and there has been disruption at some GP surgeries as a result of the attack.

NHS England said patients in an emergency should go to A&E or access emergency services as they normally would.

Dr Anne Rainsberry, NHS incident director, added: "More widely, we ask people to use the NHS wisely while we deal with this major incident, which is still ongoing."

Media playback is unsupported on your device Media caption Angry doctors, disappointed patients: Reactions to the cyber-attack on the NHS

A massive ransomware campaign appears to have attacked a number of organisations around the world, with reports of infections in more than 70 countries.

Telefonica, the Spanish telecoms company which owns mobile network O2, said it had detected a "cybersecurity incident" but that clients and services had not been affected.

Screenshots of a program that locks computers and demands a payment in Bitcoin have been shared online by those affected.

NHS Digital said the attack was believed to have been carried out by the malware variant Wanna Decryptor.

"Our focus is on supporting organisations to manage the incident swiftly and decisively, but we will continue to communicate with NHS colleagues and will share more information as it becomes available," it said.

Why has the NHS been hit so hard?

Media playback is unsupported on your device Media caption Technology explained: what is ransomware?

There could be a lot of reasons why the NHS was hit so hard by this attack.

The most likely one is because it is a huge organisation supported by a massive IT infrastructure.

It also has lots of partners and suppliers that connect to its core network.

Complexity is the enemy of security and it is a fair bet that some bits of that network, especially those operated by suppliers, are not as well maintained as they should be.

This could mean that patches that would have thwarted WannaCry were not applied.

So, as soon as the worm got in, it could run rampant.

Dr Chris Mimnagh, who works at a medical centre in Liverpool, said the attack had made its job impossible.

"Our entire patient record is accessed through the computer - blood results, history, medicines.

"Most of our prescribing is done electronically... it's sent direct to the pharmacy and... all that is not able to be accessed when we lose the clinical system."

'Power of the state'

Dr Emma Fardon, a GP in Dundee, said she had returned from house visits to find a message on the surgery's computers asking for money.

"We can't access any patient records. Everything is fully computerised," she said.

"We have no idea what drugs people are on or the allergies they have. We can't access the appointments system."

Media playback is unsupported on your device Media caption NHS chief Saffron Cordery tells PM that hospitals are cancelling their operations

Dr Afzal Ashraf, an expert on cyber-security who has previously worked as an adviser to the government, told the BBC it was likely that the malware was spreading when NHS services shared documents and information.

But he also said he thought it was unlikely the attackers had deliberately targeted the NHS.

He added: "I think they probably attacked a small company assuming they would get a small amount of money but it's got into the NHS system and now they have the full power of the state against them - because obviously the government cannot afford for this sort of thing to happen and be successful."

Get news from the BBC in your inbox, each weekday morning</s>LONDON (AP) — A large cyberattack crippled computer systems at hospitals across England on Friday, with appointments canceled, phone lines down and patients turned away.

Britain’s National Health Service said hospitals were hit by an apparent “ransomware” attack, but there was no immediate evidence that patient data had been accessed.

NHS Digital, which oversees hospital cybersecurity, says the attack used the Wanna Decryptor variant of malware, which infects and locks computers while the attackers demand a ransom.

Pictures posted on social media showed screens of NHS computers with images demanding payment of $300 worth of the online currency Bitcoin, saying: “Ooops, your files have been encrypted!”

NHS Digital said the attack “was not specifically targeted at the NHS and is affecting organizations from across a range of sectors.” It said 16 NHS organizations had reported being hit.

Spain, meanwhile, said several Spanish companies had been targeted in ransomware cyberattack that affected the Windows operating system of employees’ computers. It did not say which companies were targeted but telecommunications company Telefonica said it had detected a cybersecurity incident that had affected computers of some employees.

In the U.K., hospitals in London, northwest England and other parts of the country reported problems and asked patients not to come to the hospitals unless it was an emergency. Most of the affected hospitals were in England, but several facilities in Scotland also reported being hit.

NHS Merseyside, which operates several hospitals in northwest England, tweeted that “following a suspected national cyberattack, we are taking all precautionary measures possible to protect our local NHS systems and services.”

East and North Hertfordshire NHS Trust, which runs hospitals in an area north of London, said “the trust has experienced a major IT problem, believed to be caused by a cyberattack.”

It said its hospitals had shut down all computer systems as a protective measure and canceled all non-urgent activity.

Bart’s Health, which runs several London hospitals, said it had activated its major incident plan, cancelling routine appointments and diverting ambulances to neighboring hospitals.

Britain’s National Health Service is a source of pride for many Britons but faces substantial budget issues and has had previous problems with its huge IT system.

Ransomware attacks are on the rise. In February 2016, the Hollywood Presbyterian Medical Center in California said it had paid a $17,000 ransom to regain control of its computers from hackers.

Krishna Chinthapalli, a registrar at the National Hospital for Neurology and Neurosurgery in London, warned that British hospitals’ old operating systems and store of confidential patient information made them an ideal target for blackmailers.

Writing in the British Medical Journal, he said: “We should be prepared: more hospitals will almost certainly be shut down by ransomware this year.”

Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.</s>investigators hunted for those behind an unprecedented cyber-attack that affected systems in dozens of countries, including at banks, hospitals and government agencies, as security experts sought to contain the fallout.

The assault, which began Friday and was being described as the biggest-ever cyber ransom attack, struck state agencies and major companies around the world — from Russian banks and British hospitals to FedEx and European car factories.

"The recent attack is at an unprecedented level and will require a complex investigation to identify the culprits," said Europol, Europe's police agency.

Europol said a special task force at its European Centre was "specially designed to assist in such investigations and will play an important role in supporting the investigation".

The attacks used ransomware that apparently exploited a security flaw in operating systems, locking users' files unless they pay the attackers a designated sum in the virtual currency

Images appeared on victims' screens demanding payment of $300 in Bitcoin, saying: "Ooops, your files have been encrypted!"

Payment is demanded within three days or the price is doubled, and if none is received within seven days the files will be deleted, according to the screen message.

But experts and government alike warn against ceding to the hackers' demands.

"Paying the ransom does not guarantee the encrypted files will be released," the US Department of Homeland Security's computer emergency response team said.

"It only guarantees that the malicious actors receive the victim's money, and in some cases, their banking information."

Experts and officials offered differing estimates of the scope of the attacks, but all agreed it was huge.

Mikko Hypponen, chief research officer at the Helsinki- based cyber security company F-Secure, told AFP it was the biggest ransomware outbreak in history, saying that 130,000 systems in more than 100 countries had been affected.

He said and India were hit particularly hard, largely because Microsoft's Windows XP — one of the operating systems most at risk — was still widely used there.

French police said there were "more than 75,000 victims" around the globe, but cautioned that the number could increase "significantly".

The virus spread quickly because the culprits used a digital code believed to have been developed by the US National Security Agency — and subsequently leaked as part of a document dump, according to researchers at the Moscow-based computer security firm Kaspersky Lab.</s>LONDON (AP) — A global “ransomware” cyberattack, unprecedented in scale, had technicians scrambling to restore Britain’s crippled hospital network Saturday and secure the computers that run factories, banks, government agencies and transport systems in many other nations.

The worldwide effort to extort cash from computer users is so unprecedented that Microsoft quickly changed its policy, making security fixes available for free for the older Windows systems still used by millions of individuals and smaller businesses.

A malware tracking map showed “WannaCry” infections popping up around the world. Britain canceled or delayed treatments for thousands of patients, even people with cancer. Train systems were hit in Germany and Russia, and phone companies in Madrid and Moscow. Renault’s futuristic assembly line in Slovenia, where rows of robots weld car bodies together, was stopped cold.

In Brazil, the social security system had to disconnect its computers and cancel public access. The state-owned oil company Petrobras and Brazil’s Foreign Ministry also disconnected computers as a precautionary measure, and court systems went down, too.

Britain’s home secretary said one in five of 248 National Health Service groups had been hit. Home Secretary Amber Rudd said all but six of the NHS trusts back to normal Saturday.

The U.K.’s National Cyber Security Center was “working round the clock” to restore vital health services, while urging people to update security software fixes, run anti-virus software and back up their data elsewhere.

Who perpetrated this wave of attacks remains unknown. Two security firms — Kaspersky Lab and Avast — said they identified the malicious software in more than 70 countries. Both said Russia was hit hardest.

These hackers “have caused enormous amounts of disruption– probably the biggest ransomware cyberattack in history,” said Graham Cluley, a veteran of the anti-virus industry in Oxford, England.

And all this may be just a taste of what’s coming, another cyber security expert warned.

Computer users worldwide — and everyone else who depends on them — should assume that the next big “ransomware” attack has already been launched, and just hasn’t manifested itself yet, Ori Eisen, who founded the Trusona cybersecurity firm in Scottsdale, Arizona, told The Associated Press.

The attack held hospitals and other entities hostage by freezing computers, encrypting data and demanding money through online bitcoin payments. But it appears to be “low-level” stuff, Eisen said Saturday, given the amount of ransom demanded — $300 at first, rising to $600 before it destroys files hours later.

He said the same thing could be done to crucial infrastructure, like nuclear power plants, dams or railway systems.

“This is child’s play, what happened. This is not the serious stuff yet. What if the same thing happened to 10 nuclear power plants, and they would shut down all the electricity to the grid? What if the same exact thing happened to a water dam or to a bridge?” he asked.

“Today, it happened to 10,000 computers,” Eisen said. “There’s no barrier to do it tomorrow to 100 million computers.”

This is already believed to be the biggest online extortion attack ever recorded, disrupting services in nations as diverse as the U.S., Ukraine, Brazil, Spain and India. Europol, the European Union’s police agency, said the onslaught was at “an unprecedented level and will require a complex international investigation to identify the culprits.”

In Russia, government agencies insisted that all attacks had been resolved. Russian Interior Ministry, which runs the national police, said the problem had been “localized” with no information compromised. Russia’s health ministry said its attacks were “effectively repelled.”

The ransomware appeared to exploit a vulnerability in Microsoft Windows that was purportedly identified by the U.S. National Security Agency for its own intelligence-gathering purposes. The NSA tools were stolen by hackers and dumped on the internet.

“There’s clearly some culpability on the part of the U.S. intelligence services. Because they could have done something ages ago to get this problem fixed, and they didn’t do it, Cluley said.

“I have some sympathy toward the intelligence services, because it’s very, very difficult these days, with encryption, to spy on people,” Cluley added. “But I don’t think that those concerns should hide the fact that ALL of us need to be protected … We’re living an online life, and we all deserve security there.”

It could have been much worse if not for a young cybersecurity researcher who helped to halt its spread by accidentally activating a so-called “kill switch” in the malicious software.

The 22-year-old Britain-based researcher, identified online only as MalwareTech, explained Saturday how he registered a garbled domain name he spotted in the code. His $11 purchase of the name on Friday activated the domain, which commanded the malware to stop spreading. It may have saved governments and companies millions of dollars and slowed the outbreak before U.S.-based computers were more widely infected.

Indeed, while FedEx Corp. reported that its Windows computers were “experiencing interference” from malware — it wouldn’t say if it had been hit by the ransomware — other impacts in the U.S. were not readily apparent on Saturday.

The kill switch couldn’t help those already infected, however. Short of paying, options for these individuals and companies are usually limited to recovering data files from a backup, if available, or living without them.

Security experts said it appeared to be caused by a self-replicating piece of software that enters companies when employees click on email attachments, then spreads quickly as employees share documents.

The security holes it exploits were disclosed weeks ago by TheShadowBrokers, a mysterious group that published what it said are hacking tools used by the NSA. Microsoft swiftly announced that it had already issued software “patches” to fix those holes, but many users haven’t yet installed updates or still use older versions of Windows.

Microsoft had made fixes for older systems, such as 2001’s Windows XP, available only to mostly larger organizations, including Britain’s National Health Service, that paid extra for extended technical support.

In light of Friday’s attacks, Microsoft announced that it’s making the fixes free to all.

Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.</s>In this May 12, 2017 photo, a display panel with an error can be seen at the main railway station in Chemnitz, Germany.

LONDON (AP) — A global "ransomware" attack, unprecedented in scale, had technicians scrambling to restore Britain's crippled hospital network Saturday and secure the computers that run factories, banks, government agencies and transport systems in many other nations.

The worldwide cyberextortion attack is so unprecedented, in fact, that Microsoft quickly changed its policy, announcing security fixes available for free for the older Windows systems still used by millions of individuals and smaller businesses.

After an emergency government meeting Saturday in London, Britain's home secretary said one in five of 248 National Health Service groups had been hit. The onslaught forced hospitals to cancel or delay treatments for thousands of patients, even some with serious aliments like cancer.

Home Secretary Amber Rudd said 48 NHS trusts were affected and all but six were now back to normal. The U.K.'s National Cyber Security Center said it is "working round the clock" to restore vital health services.

Security officials in Britain urged organizations to protect themselves by updating their security software fixes, running anti-virus software and backing up data elsewhere.

Who perpetrated this wave of attacks remains unknown. Two security firms — Kaspersky Lab and Avast — said they identified the malicious software in more than 70 countries. Both said Russia was hit hardest.

"This is obviously by far the worst ransomware outbreak we've seen in, I think, forever," said Lawrence Abrams, a New York-based malware expert who runs BleepingComputer.com.

And all this may be just a taste of what's coming, a leading cyber security expert warned.

Computer users worldwide — and everyone else who depends on them — should assume that the next big "ransomware" attack has already been launched, and just hasn't manifested itself yet, Ori Eisen, who founded the Trusona cybersecurity firm in Scottsdale, Arizona, told The Associated Press.

The attack held hospitals and other entities hostage by freezing computers, encrypting data and demanding money through online bitcoin payments. But it appears to be "low-level" stuff, Eisen said Saturday, given the amount of ransom demanded — $300 at first, rising to $600 before it destroys files hours later.

He said the same thing could be done to crucial infrastructure, like nuclear power plants, dams or railway systems.

"This is child's play, what happened. This is not the serious stuff yet. What if the same thing happened to 10 nuclear power plants, and they would shut down all the electricity to the grid? What if the same exact thing happened to a water dam or to a bridge?" he asked.

"Today, it happened to 10,000 computers," Eisen said. "There's no barrier to do it tomorrow to 100 million computers."

This is already believed to be the biggest online extortion attack ever recorded, disrupting services in nations as diverse as the U.S., Russia, Ukraine, Spain and India. Europol, the European Union's police agency, said the onslaught was at "an unprecedented level and will require a complex international investigation to identify the culprits."

The ransomware appeared to exploit a vulnerability in Microsoft Windows that was purportedly identified by the U.S. National Security Agency for its own intelligence-gathering purposes. The NSA tools were stolen by hackers and dumped on the internet.

A young cybersecurity researcher has been credited with helping to halt the ransomware's spread by accidentally activating a so-called "kill switch" in the malicious software.

The 22-year-old Britain-based researcher, identified online only as MalwareTech, explained Saturday how he inadvertently discovered Friday that the software's spread could be stopped by registering a garbled domain name. His $11 purchase of the name may have saved governments and companies around the world millions, slowing its spread before U.S.-based computers were more widely infected.

In the U.S., FedEx Corp. reported that its Windows computers were "experiencing interference" from malware, but wouldn't say if it had been hit by ransomware. Other impacts in the U.S. were not readily apparent on Saturday.

The kill switch couldn't help those already infected, however. Short of paying, options for these individuals and companies are usually limited to recovering data files from a backup, if available, or living without them.

Security experts said it appeared to be caused by a self-replicating piece of software that enters companies when employees click on email attachments, then spreads quickly as employees share documents.

The security holes it exploits were disclosed weeks ago by TheShadowBrokers, a mysterious group that published what it said are hacking tools used by the NSA. Microsoft swiftly announced that it had already issued software "patches" to fix those holes, but many users haven't yet installed updates or still use older versions of Windows.

Before Friday's attack, Microsoft had made fixes for older systems, such as 2001's Windows XP, available only to mostly larger organizations that paid extra for extended technical support. Microsoft says now it will make the fixes free for everyone.

Krishna Chinthapalli, a doctor at Britain's National Hospital for Neurology & Neurosurgery who wrote a paper on cybersecurity for the British Medical Journal, said many British hospitals still use Windows XP software, introduced in 2001.

In Russia, government agencies insisted that all attacks had been resolved. Russian Interior Ministry, which runs the national police, said the problem had been "localized" with no information compromised. Russia's health ministry said its attacks were "effectively repelled."

"When we say that the health ministry was attacked, you should understand that it wasn't the main server, it was local computers ... actually nothing serious or deadly happened yet," German Klimenko, a presidential adviser, said on Russian state television.

Russian cellular phone operators Megafon and MTS were hit. The national railway said it was attacked but operations were unaffected. Russia's central bank said Saturday that no incidents were "compromising the data resources" of Russian banks.

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. Deutsche Bahn said it deployed extra staff to help customers.

French carmaker Renault's assembly plant in Slovenia halted production after it was targeted. Radio Slovenia said Saturday the Revoz factory in the southeastern town of Novo Mesto stopped working Friday evening to stop the malware from spreading.

Elsewhere in Europe, the attack hit Spain's Telefonica, a global broadband and telecommunications company, and knocked ticketing offline for Norway's IF Odd, a 132-year-old soccer club.

Heintz reported from Moscow and Breed from Raleigh, N.C.</s>'Biggest ransomware outbreak in history' hits nearly 100 countries with data held for ransom

Updated

Dozens of countries have been hit with a huge cyber extortion attack that locked computers and held users' files for ransom at a multitude of hospitals, companies and government agencies.

How did the attack occur? Attack appeared to be caused by a self-replicating piece of software that takes advantage of vulnerabilities in older versions of Microsoft Windows, security experts say

It spreads from computer to computer as it finds exposed targets.

Ransom demands start at $US300 and increase after two hours, a security researcher at Kaspersky Lab says

Security holes were disclosed several weeks ago by TheShadowBrokers, a mysterious group that has repeatedly published what it says are hacking tools used by the NSA

Shortly after that disclosure, Microsoft announced it had already issued software "patches" for those holes

But many companies and individuals have not installed the fixes yet or are using older versions of Windows that the company no longer supports and for which no patch was available

The most disruptive attacks were reported in Britain, where hospitals and clinics were forced to turn away patients after losing access to computers, but other countries — including Spain, Portugal and Russia — have also been targeted.

Cyber extortionists tricked victims into opening malicious malware attachments to spam emails that appeared to contain invoices, job offers, security warnings and other legitimate files.

The ransomware encrypted data on the computers, demanding payments of $300 to $600 to restore access. Security researchers said they observed some victims paying via the digital currency bitcoin, though they did not know what per cent had given in to the extortionists.

Mikko Hypponen, chief research officer at Helsinki-based cybersecurity company F-Secure, called it "the biggest ransomware outbreak in history".

The malicious software behind the onslaught appeared to exploit a vulnerability in Microsoft Windows that was supposedly identified by the National Security Agency for its own intelligence-gathering purposes and was later leaked to the internet.

Researchers with security software maker Avast said they had observed 57,000 infections in 99 countries with Russia, Ukraine and Taiwan the top targets.

Chris Wysopal of the software security firm Veracode said criminal organisations were probably behind the attack, given how quickly the malware spread.

"For so many organisations in the same day to be hit, this is unprecedented," Mr Wysopal said.

But Alan Woodward, visiting professor of computing at the University of Surrey, said he did not believe it was a targeted attack.

"But will simply have been that the ransomware has sought out those organisations that are running susceptible devices," Mr Woodward said.

The US Department of Homeland Security said late on Friday (local time) that it was aware of reports of the ransomware, was sharing information with domestic and foreign partners and was ready to lend technical support.

The Group of Seven (G7) rich nations, which are holding a two-day meeting of finance ministers and central bankers in Italy, released a draft statement committing to join forces to fight the rising threat of cyber attacks.

"We recognise that cyber incidents represent a growing threat for our economies and that appropriate economy-wide policy responses are needed," the draft statement said.

It called for common shared practices to spot quickly any vulnerabilities in the world's financial system and stressed the importance of effective measures to assess cyber security among individual financial firms and at sector level.

Patients turned away as hospitals hit with ransomware

Private security firms identified the ransomware as a new variant of "WannaCry" that had the ability to automatically spread across large networks by exploiting a known bug in Microsoft's Windows operating system.

The hackers, who have not come forward to claim responsibility or otherwise been identified, likely made it a "worm," or self-spreading malware, by exploiting a piece of NSA code known as "Eternal Blue" that was released last month by a group known as the Shadow Brokers, researchers with several private cyber security firms said.

Microsoft said it was pushing out automatic Windows updates to defend clients from WannaCry. It issued a patch on March 14.

The attack froze computers at hospitals across Britain, shutting down wards, closing emergency rooms and bringing medical treatments to a halt.

NHS Digital, which oversees hospital cybersecurity, said the attack was affecting organisations from across a range of sectors.

Many hospitals cancelled all routine procedures and warned patients not to come to hospital unless it was an emergency. Some chemotherapy patients were even sent home because their records could not be accessed.

Several facilities in Scotland also reported being hit. Doctors' practices and pharmacies reported similar problems.

Russia appeared to be the hardest hit, according to security experts, with the country's Interior Ministry confirming it was struck.

The interior ministry said on its website that around 1,000 computers had been infected but it had localised the virus.

In addition to Russia, the biggest targets appeared to be Ukraine and India, nations where it is common to find older, unpatched versions of Windows in use, according to security firm Kaspersky Lab's count.

A spokesman for Prime Minister Malcolm Turnbull said there had been no confirmed reports of an impact on Australian organisations at this stage.

He said the Federal Government was closely monitoring the situation.

"The Prime Minister's Cyber Security Special Adviser is working with the Australian Cyber Security Centre and health agencies in Australia to determine any impact to Australia," he said.

In Spain, some big firms took pre-emptive steps to thwart ransomware attacks following a warning from Spain's National Cryptology Centre of "a massive ransomware attack".

Iberdrola and Gas Natural, along with Vodafone's unit in Spain, asked staff to turn off computers or cut off internet access in case they had been compromised, representatives from the firms said.

British cyber centre says it is investigating attack

Leading international shipper FedEx Corp said it was one of the companies whose system was infected with the malware that security firms said was delivered via spam emails.

"Like many other companies, FedEx is experiencing interference with some of our Windows-based systems caused by malware," the company said in a statement.

Only a small number of US-headquartered organisations were infected because the hackers appear to have begun the campaign by targeting organisations in Europe, a research manager with security software maker Symantec said.

By the time they turned their attention to US organisations, spam filters had identified the new threat and flagged the ransomware-laden emails as malicious, Vikram Thakur said.

Telecommunications company Telefonica was among many targets in Spain, though it said the attack was limited to some computers on an internal network and had not affected clients or services.

Portugal Telecom and Telefonica Argentina both said they were also targeted.

Britain's 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.

British government officials and intelligence chiefs have repeatedly highlighted the threat to critical infrastructure and the economy from cyberattacks, with the National Cyber Security Centre reporting it had detected 188 "high-level" attacks in just three months.

AP/Reuters

Topics: internet-technology, healthcare-facilities, terrorism, united-kingdom, european-union

First posted</s>(CNN) A massive global ransomware attack has struck hospitals, companies and government offices around the world, seizing control of affected computers until the victims pay a ransom.

The majority of the attacks targeted Russia, Ukraine and Taiwan. But the National Health Service in the United Kingdom and global firms such as FedEx also reported they had come under assault Friday. Experts suggested Saturday that the ransomware's progress had been halted, but new attacks could soon follow.

Here are five things to know:

It may not be over yet

Cybersecurity experts have been working around the clock to try to halt the malware attack that is unprecedented in scale.

The ransomware's progress has been halted by the accidental discovery late Friday of a "kill switch" hidden within the code by a security researcher, said cybersecurity consultant David Kennedy, formerly of the US National Security Agency.

"The software has actually stopped spreading across the world," he told CNN.

"He actually probably saved lives by accident," Kennedy said, referring to the security researcher who discovered the kill switch.

The ransomware was designed to repeatedly contact an unregistered domain listed in its code. The security researcher -- who uses the Twitter handle @MalwareTechBlog -- registered that domain to collect the ransomware traffic for analysis and to track infections.

However, a hacker could change the code to remove the domain and try the ransomware attack again.

Also, the kill switch won't help anyone whose computer was already infected. Individuals and companies still have to decide if they want to pay the ransom or part with their data.

Michael Gazeley, managing director of cybersecurity firm Network Box, told CNN that the danger is far from over and that a company's security patch on Saturday might not still work by Monday.

"A lot of people are going to go to work on Monday and click on a link in their mail -- completely oblivious that all of this is going on or have heard about it and think that it's over -- and suddenly wipe out their whole company," Gazeley said from Hong Kong.

"IT managers need to be extremely aware that new variants of this ransomware attack are being launched almost hourly, so they can't just check that their computer systems are protected, then relax, assuming everything will stay that way," he said.

Cybersecurity firm Avast said it tracked more than 75,000 ransomware attacks in 99 countries Friday.

European police agency Europol said it was working to support countries, saying the malware attack was at an "unprecedented level and requires international investigation."

The malware is spread by taking advantage of a Windows vulnerability that Microsoft released a security patch for in March. But computers and networks that didn't update their systems remained at risk.

Mikko Hypponen, chief research officer at cybersecurity company F-Secure in Helsinki, Finland, called it "the biggest ransomware outbreak in history," according to an online post.

The cyberattack affected 16 organizations that are part of the National Health Service on Friday, causing some surgical procedures to be canceled and ambulances diverted. But the NHS said Saturday it does not have any evidence that patient data was breached.

A senior nurse with NHS Lanarkshire in Scotland posted a video on Twitter appealing to members of the public "to stay away from acute hospitals unless it's an absolute emergency situation" while its IT systems remain affected.

Grant Gowers, 50, from Clacton-on-Sea in southern England, told CNN how the ransomware attack had directly affected him. Doctors told him two weeks ago they needed to schedule a prostate biopsy to determine if he has cancer.

But around 5 p.m. Friday he got a call to say his biopsy had been canceled as a result of the ransomware attack.

"I have built myself up for the last two weeks," he told CNN. "If I know I have cancer, I could deal with it."

His procedure is being rescheduled within the next two weeks. But that's not good enough for Gowers. "I really want to grab the person who done this today and give him a picture of how this is affecting my life," he said.

The UK government has called a meeting of its crisis response committee, known as Cobra, on Saturday to discuss the situation.

Here's what you should do

If your computer has been affected, there's no guarantee that paying the ransom will restore it, Gazeley said. In past ransomware attacks, some victims have paid, only to find the key they are given doesn't work, while others have found their files are corrupted and can't be properly restored, he said.

Managers at many companies and other organizations have not taken steps to put proper cybersecurity systems in place despite talking about their importance, Gazeley said. "Most organizations just keep their heads in the sand," he said.

No one has yet identified the culprit.

"We see all the finger-pointing at the usual suspects, saying it's probably people in Russia or China, but, to quote Sherlock Holmes, it's not really a good idea to guess without the evidence," Gazeley said. Bitcoin is set up to be untraceable, so investigators will struggle to follow a money trail, he said.

Nonetheless, authorities around the world will be seeking to track down those responsible.

"I think these hackers have to recognize that these authorities will come after them with a vengeance," Gazeley said.

It also may never be known how much the hackers have netted from the ransomware attack. Many firms are unlikely to want to reveal they fell victim to it and whether they paid up.
A large scale international cyber-attack using the WannaCry ransomware package disrupts computer and telephone systems in thousands of cases across 99 countries. Affected organisations include: England's NHS, with doctors reporting messages demanding money; MegaFon and Sberbank in Russia; Telefónica, Iberdrola, and Gas Natural in Spain; and FedEx.