The spread of the virus WannaCry, which locked up more than 100,000 computers, had slowed on Sunday, but new versions of the worm were expected even while the world was yet to take stock of the extent of damage from Friday's attack. The initial attack had started after many offices had closed Friday.
The full extent of the damage from the cyberattack felt in 150 countries was unclear and could worsen if more malicious variations of the online extortion scheme appear. Seeing businesses and individuals affected by cyberattacks, such as the ones reported today, was painful.
French automaker Renault and its partner, Nissan, say their plants were hit by the attack, NBC reports.
Among the worst hit was the National Health Service (NHS) in England and Scotland.
"It's one of those things, in a ideal world, if people were up to date on the patches, this wouldn't be a problem", O'Leary said.
Last week, hundreds of thousands of Windows-based PCs were infected with ransomware.
Problems with cyber security in NHS organisations were highlighted past year by Dame Fiona Caldicott, the national data guardian, who warned that issues were given insufficient priority and that health bodies persisted in using obsolete computer systems, The Times said. Amongst those were systems of Andhra Pradesh police department, manufacturing companies in Delhi, 2 sme's in Delhi and one big corporate house in Mumbai.
Patched computers carry a much lower risk of being infected by malware or ransomware than those without an update.
Patients arriving at Dharmais Cancer Hospital had to wait several hours while staff worked with paper records.
He said the ransomware attack was exploiting vulnerabilities in the Microsoft Windows operating System especially those not now supported such as Windows XP, Windows 8, Windows Server 2003.
Eiichi Moriya, a cybersecurity expert and professor at Meiji University, warned that paying the ransom would not guarantee a fix. "It's like after a robber enters your home. If someone kidnaps your child, you may pay your ransom but there is no guarantee your child will return".
Researchers remained on high alert for new variants that could lead to a fresh wave of infections. One did not include the so-called kill switch that allowed researchers to interrupt the malware's spread Friday by diverting it to a dead end on the internet.
According to Ryan Kalember, senior Vice President of cyber security strategy at the cybersecurity firm Proofpoint, a "ransomware worm" using the essentially unaltered NSA code is spreading across corporate networks in at least 74 countries, with European and Asian countries among the hardest hit.
"I still expect another to pop up and be fully operational", Kalember said.
On affected computers, the WannaCry software encrypts files and displays a ransom message demanding $300 in bitcoin.
Experts fear the situation could further aggravate as a number of computers in India run on the older operating systems and have not been updated yet.
Nations need to see the attack as a wake-up call, said Smith.
"The numbers are still going up", Wainwright said.
Brad Smith, the technology firm's president and chief legal officer, criticised U.S. intelligence agencies the CIA and the National Security Agency (NSA) for "stockpiling" software code which could be exploited by hackers.
The ransomware worm that stopped auto factories, hospitals, shops and schools over the weekend worldwide, with Asia having escaped the worst so far, could wreak fresh havoc on Monday when employees log back on, cyber security experts warned.