Hospitals and doctors' surgeries in parts of England on Friday were forced to turn away patients and cancel appointments after they were infected with the "ransomware", which scrambled data on computers and demanded payments of $300 to $600 to restore access. The IT systems of NHS sites were reportedly bombarded by pop-up messages demanding a ransom in order to gain access.
At least 16 National Health Service-related organizations were affected, officials said, although patients' medical information did not appear to be compromised.
NHS Digital, which oversees hospital cybersecurity, says the attack used the Wanna Decryptor variant of malware, which holds affected computers hostage while the attackers demand a ransom.
India was among the three countries worst affected by the attack, data shared by Kaspersky showed.
Jakub Kroustek of Avast said on Twitter the security firm had detected "36,000 detections of #WannaCry (aka #WanaCypt0r aka #WCry) #ransomware so far".
Attacks were being reported in Britain and 11 other countries, including Turkey, Vietnam, the Philippines and Japan, with the majority of affected computers in Russian Federation.
Alan Woodward, visiting professor of computing at the University of Surrey, said there was evidence the ransomware was spreading using a Microsoft flaw exposed in a recent leak of information from US intelligence agencies.
Yes, they can. A hospital system in Los Angeles paid about $17,000 earlier this year following an attack that blocked hospital employees from using email and other forms of electronic communication by using encryption to lock them out of the system.
Incidents around the world appear to be linked may not be a coordinated attack on specific targets. Russia, Ukraine and Taiwan were the top targets, it said.
Among the many other institutions that were affected were hospitals and telecommunications companies across Europe, Russia, Asia and beyond, according to MalwareHunterTeam, a security firm that tracks ransomware attacks. The malware then displays a window informing users that their files have been encrypted and that they can be recovered in lieu of a payment made in bitcoin. Many canceled all routine procedures and asked patients not to come to the hospitals unless it was an emergency.
Apple iPhone 5s is the top smartphone in India
While global iPhone unit sales were down marginally year on year, the company had plenty to cheer about its performance in India. OPPO is largely unknown in the Western world, but its brand is wildly popular in China and growing rapidly across India.
That's the Tooth: Celtics guard Thomas has more dental work
They handily controlled the entire game, outscoring the Celtics 39-17 in the first quarter and never trailing on the scoreboard. Boston shot just 31-percent in the third quarter and Isaiah Thomas was held to just two points and five costly turnovers.
Kosovo government loses no-confidence vote, coalition fails
Political deadlock over a border demarcation agreement with Montenegro has led to the downfall of Kosovo's coalition government. Montenegro recognised Kosovo's independence in 2008, much to the anger of Serbia, and of the Serbian community in Montenegro .
"This is not targeted at the NHS, it's an worldwide attack and a number of countries and organisations have been affected", said Prime Minister Theresa May.
A statement released by Colchester General Hospital said: "On Friday the trust experienced a major IT problem, believed to have been caused by the cyberattack".
Still, only a small number of US-headquartered organizations were hit because the hackers appear to have begun the campaign by targeting organizations in Europe, said Vikram Thakur, research manager with security software maker Symantec.
In a tweet, Europol Director Rob Wainwright said the cyberattack on British health care institutions "follows trend from U.S. of ransomware attacks on health care trusts".
The emergencies ministry told Russian news agencies it had repelled the cyberattacks while Sberbank said its cyber security systems had prevented viruses from entering its systems.
Perhaps the most significant target thus far has been Britain's National Health Service, that nation's main healthcare apparatus.
Forcepoint said in a statement that the attack had "global scope", affecting organisations in Australia, Belgium, France, Germany, Italy and Mexico.
The attacks did not disrupt the provision of services or networks operations of the victims, the Spanish government said in a statement.
Spain, meanwhile, activated a special protocol to protect critical infrastructure in response to the "massive infection" of personal and corporate computers in ransomware attacks. The company said its systems hadn't been affected, according to Reuters.