The cyber attack was first reported from Sweden, Britain and France, US media outlets reported.
Union members at French carmaker Renault say the global cyberattack has forced it to halt production at sites in France in an effort to stop the malware from spreading.
Meanwhile, the MalwareTech tracker detected over 100,000 infected systems over the past 24 hours. Among the countries infected are the US, China, Russia, Spain, and the UK.
Cyber security experts are still scrambling to contain a global ransomware attack that has infected tens of thousands of computers in almost 100 countries, including the U.S., U.K., Russia, China, Ukraine, and India. It has been widely reported the hackers have demanded the ransom be paid in cryptocurrency bitcoin. The malware spreads through e-mail.
"Seeing a large telco like Telefonica get hit is going to get everybody anxious", said Chris Wysopal, chief technology officer with cyber security firm Veracode.
"Today our engineers added detection and protection against new malicious software known as Ransom:Win32.WannaCrypt", Microsoft said in a statement.
The attack, which locked up computers and held users' files for ransom, was believed the biggest of its kind ever recorded.
"The situation is changing and impacting organisations in a range of different ways", a spokesperson said. This particular strain, WannaCry, exploits a vulnerability in Windows that many systems have not yet patched.
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.
She told the BBC's Today programme: "Windows XP is not a good platform for keeping your data as secure as the modern ones, because you can't download the effective patches and anti-virus software for defending against viruses".
"We are experiencing a major IT disruption and there are delays at all of our hospitals", it said.
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The heads of state and government are expected to gather for a G7 major summit in the city of Taormina, Sicily, on May 26-27. They also called for a renewed common effort against cybercrime.
Researchers with Czech Republic-based security software maker Avast said 60 per cent of infected computers were located in Russian Federation, followed by Ukraine and Taiwan.
The DHS has a cadre of cyber security professionals that can provide expertise and support to critical infrastructure entities, it said in a statement.
The ransomware was developed using code posted online by a hacker group who said at the time that it was from the US National Security Agency.
Former NSA contractor Edward Snowden blamed the NSA for not preventing the global cyber attack.
By the time they turned their attention to the United States, spam filters had identified the new threat and flagged the ransomware-laden emails as malicious, Thakur said. Shadow Brokers said that they obtained it from a secret NSA server.
NHS Digital said it was working with the government's National Cyber Security Centre, the Department of Health and NHS England to help the organizations affected "manage the incident swiftly and decisively".
Lord, who described an attack of this type as "inevitable", said the impact was exacerbated because most NHS Trusts had "a poor understanding of network configuration meaning everything has to shut down".
HOSPITAL bosses were this morning advising patients to attend clinics and appointments as usual as they stressed The Dudley Group NHS Foundation Trust was not among trusts hit by the NHS cyber attack.
London, May 13 An Indian-origin doctor based in London had warned against the cyber-hack of the UK's state-run National Health Service just days before it crippled the country's network.
"We're not able to tell who's behind the attack", home secretary Amber Rudd told the BBC on Saturday.