LONDON (Dispatches) -- The global cyberattack has hit more than 200,000 victims in more than 150 countries, Europol executive director Rob Wainwright said Sunday.
"We've never seen anything like this," he told Britain's ITV television. "The latest count is over 200,000 victims in at least 150 countries. Many of those victims will be businesses, including large corporations."
The global cyber attack described as unprecedented in scale forced a major European automaker to halt some production lines while hitting schools in China and hospitals in Indonesia on Saturday, though it appeared to die down a day after its launch.
Capitalizing on spying tools believed to have been developed by the U.S. National Security Agency, the cyber assault has infected tens of thousands of computers in nearly 100 countries, with Britain's health system suffering the worst disruptions.
Cyber extortionists tricked victims into opening malicious malware attachments to spam emails that seemed to contain invoices, job offers, security warnings and other legitimate files.
Once inside the targeted network, so-called ransomware made use of recently revealed spy tools to silently infect other out-of-date machines without any human intervention. This, security experts said, marked an unprecedented escalation in the risk of fresh attacks spreading in the coming days and weeks.
The ransomware encrypted data on the computers, demanding payments of $300 to $600 to restore access. Researchers observed some victims paying via the digital currency bitcoin, though no one knows how much may have been transferred to extortionists because of the largely anonymous nature of such transactions.
Researchers with security software maker Avast said they had observed 126,534 ransomware infections in 99 countries, with Russia, Ukraine and Taiwan the top targets.
The hackers, who have not come forward to claim responsibility or otherwise been identified, took advantage of a worm, or self-spreading malware, by exploiting a piece of NSA spy code known as "Eternal Blue" that was released last month by a hackers group known as the Shadow Brokers, according to researchers with several private cyber security firms.
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.
Nissan's manufacturing plant in Sunderland, northeast England, was also affected by the cyber assault though "there has been no major impact on our business", a spokesman for the Japanese carmaker said.
German rail operator Deutsche Bahn said some electronic signs at stations announcing arrivals and departures were infected, with travellers posting pictures showing some bearing a message demanding a cash payment to restore access.