Alex Abdo, a staff attorney at the Knight First Amendment Institute at Columbia University, said Microsoft and other software companies have strategically settled lawsuits that could lead to court rulings weakening their licensing agreements.
"I was actually panicking because because one of my analysts made a mistake and they had said by registering the url we had started the infection", the unnamed researcher told ABC News.
In the evening, the Maharashtra Police department said it was partially hit by the ransomware."Cyber experts have been engaged to fix the systems", a senior police officer said.
NHS hospitals are still struggling in the fight against a global ransomware attack, with computer systems in several hospitals locked three days after the initial outbreak and previously unaffected hospitals revealed to have fallen to WannaCrypt ransomware.
Mr Smith said the "ransomware" attacks had used data stolen from the NSA earlier this year - which contained information on software vulnerabilities the government had hoped to hoard - and subsequently leaked them online.
The software giant compared the severity of the attack with "the United States military having some of its Tomahawk missiles stolen".
Microsoft distributed the patch two months ago, which could have forestalled much of the attack, but in many organizations it was likely lost among the blizzard of updates and patches that large corporations and governments strain to manage. Most stations had recovered.
When the National Security Agency lost control of the software behind the WannaCry cyberattack, it was like "the USA military having some of its Tomahawk missiles stolen", Microsoft President Brad Smith says, in a message about the malicious software that has created havoc on computer networks in more than 150 countries since Friday. So far, not many people have paid the ransom demanded by the malware, Europol spokesman Jan Op Gen Oorth told The Associated Press.
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Experts urged organizations and companies to immediately update older Microsoft operating systems, such as Windows XP, with a patch released by Microsoft Corp.to limit vulnerability to a more powerful version of the malware - or to future versions that can't be stopped.More news: Dems push 'grand bargain' votes in Senate, declare progress
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U.S. package delivery giant FedEx, Spanish telecoms giant Telefonica and Germany's Deutsche Bahn rail network were among those hit in the attacks, which demanded money to allow users to unblock their computers.
Installing the patch is one way to secure computers against the virus.
"It was essentially an indiscriminate attack across the world", Europol director Rob Wainwright said.
"Or we could potentially see copycats mimic the delivery or exploit method they used", he said.
Experts and governments alike warn against ceding to the demands and Wainwright said few victims so far had been paying up.
A hacking group called Shadow Brokers released the malware in April, claiming to have discovered the flaw from the NSA, Kaspersky said. He added that ransomware attacks were normally criminal rather than political in nature.
The Japan Computer Emergency Response Team Co-ordination Centre said 2,000 computers at 600 companies in Japan had been affected. The central bank reportedly said those monitoring the cyberattacks found "no incidents compromising data resources of banking institutions".
Russian Federation said its banking system was among the victims of the attacks, along with the railway system, although it added that no problems were detected. Germany's national railway saw major disruptions in its operation, while French carmaker Renault was forced to halt its production line in Slovenia to stop the malware from spreading.
A fifth of regional hospital associations in Britain's National Health Service were affected and several still had to cancel appointments on Monday, as doctors warned of delays as they can not access medical records.