"Ambulances are being diverted to neighbouring hospitals". The opposition Labour Party accused the Conservative government of leaving the National Health Service vulnerable. Hackers are threatening the users that if they do not pay within the set deadline they will delete all the files on the users' systems, however, governments are asking the citizens not to pay the ransom, as it would encourage the hackers to go for more such attacks.
More than 75,000 similar attacks reportedly happened in nearly 100 countries, with Russia, Ukraine and Taiwan hardest hit, according to the cybersecurity firm Avast. The attack on Britain's NHS was potentially the most devastating as thousands of patients' appointments were cancelled, ambulances rerouted, records lost and chaos followed, despite the warnings delivered, some as recently as a year ago, on the vulnerability of outdated systems.
'There have also been other reports made to our online cyber security network and the difficulty is of course there are literally hundres of instances of ransomware in Australia each week and so we are now seeking to confirm whether these are examples of the particular ransomware that has cause so much havoc for example in the United Kingdom'.
It's yet another example of how important it is to update software.
Carmaker Renault said one of its French plants, which employs 3,500 people, wasn't reopening Monday as a "preventative step" while technicians deal with the aftermath of the attack.
Savvides noted that it is unlikely that the user will notice the ransomware is encrypting until it's too late.
"Once the encryption process starts, there is little the user can do, as it happens very quickly", says Nick Savvides, Security Advocate, Symantec Asia Pacific and Japan.
"More than 40,000 businesses and institutions in China have been struck by the malware, according to state media", Schmitz says.
The virus hit computers running older versions of Microsoft software that had not been recently updated.
In the USA, where the effects haven't appeared to be widespread, investigators believe additional companies have been attacked but have not yet come forward to report it, a law enforcement official told The Associated Press.
British PM Addresses Cyberattack on National Health Service
Just one click on an infected attachment or bad link would lead to all computers in a network becoming infected, said Vikram Thakur, technical director of Symantec Security Response. Machines that contained the patch are much less at risk than those that didn't.
"The truth is, if you're going to cut infrastructure budgets and if you're not going to allow the NHS to invest in upgrading its IT, then you are going to leave hospitals wide open to this sort of attack".
There are almost 150 million computers running Windows XP operation system globally.
The minister also confirmed the attack wasn't on a government organisation. "It was clear warnings were given to hospital trusts".
The attack therefore spread faster than previous, smaller-scale ransomware attacks.
Chinese government bodies from transport, social security, industry watchdogs and immigration said they had suspended services ranging from processing applications to traffic crime enforcement. "Just patch their systems as soon as possible", MalwareTech said. "We don't have a precedent for something of this scale (in China)", said Marin Ivezic, a cybersecurity expert at PwC in Hong Kong.
In Brazil, the social security system had to disconnect its computers and cancel public access.
Europe and Russian Federation were hit the hardest.
An exterior view shows the main entrance of St Bartholomew's Hospital, in London, one of the hospitals whose computer systems were affected by a cyberattack, Friday, May 12, 2017. Companies including Hitachi and Nissan Motor Co. reported problems but said they said had not seriously affected their business operations. "There's no barrier to do it tomorrow to 100 million computers".