A huge cyber attack leveraging hacking tools widely believed to have been developed by the U.S. National Security Agency brought disruption to Britain's health system on Friday and infected dozens of other countries around the world, security researchers said.
"To ensure that all back-up processes and procedures were put in place quickly, the trust declared a major internal incident to make sure that patients already in the trust's hospitals continued to receive the care they need".
"This attack was not specifically targeted at the NHS and is affecting organisations from across a range of sectors", NHS Digital, the computer arm of the health service, said in a statement.
"We are aware that a number of NHS (National Health Service) organizations have reported they have suffered from a ransomware attack", May said, while speaking on the campaign trail in the UK. Most of the affected hospitals were in England, but several facilities in Scotland also reported being hit.
Christian cyber security expert and author of "The Future of Almost Everything" told Premier more about the attack.
United Lincolnshire Hospitals NHS Trust said it was cancelling all outpatient, endoscopy, cardiology and radiology weekend appointments because of the attack, which had affected Lincoln County Hospital, Pilgrim Hospital and Grantham Hospital.
There is evidence that the attack has spread into the USA, according to an email the Office of the National Coordinator for Health Information Technology sent Friday afternoon that urges the healthcare industry to "continue to exercise cybersecurity best practices-particularly with respect to email".
NHS Western Isles, NHS Fife and NHS Borders also said they had, to some degree, been disrupted.
In the case of WannaCry, the program encrypts your files and demands payment in bitcoin in order to regain access.
"It's been out for nearly two weeks now, and until very recently it's just been sitting there", Abrams said.
Ambulances were diverted and patients were warned to avoid some A&E departments.
Spain said on Friday a large number of companies, including telecommunications giant Telefonica TEF.MC , had been infected with malicious software known as "ransomware" which locks up computers and demands ransoms.
The statement said "due to the efficient cooperation between the institutions, the attack was prevented as were damages, as the targets were identified as well as the methodology of the attack".
Microsoft issued a security update on March 14 about vulnerabilities in the Windows system.
British government officials and intelligence chiefs have repeatedly highlighted the threat to critical infrastructure and the economy from cyberattacks.
Russian Interior Ministry spokeswoman Irina Volk confirmed that there was a ransomware attack on its computers.
The computer systems of 16 NHS hospitals were hacked, denying access to physicians unless a ransom was paid.
Chris Mimnagh, another doctor in Liverpool, told the Guardian: "Unable to access our clinical system - as a precaution our area has severed links to the wider NHS, which means no access to our national systems, no computers means no records, no prescriptions, no results".