Cyber bad guys have spread ransomware, known as WannaCry, to computers around the world. In a matter of hours, infected hospitals started turning away patients, compromised video displays in train stations and apartment buildings locked up, and banks, delivery companies and manufacturers disconnected computers, either because they were no longer had access to crucial data or out of fear they might become infected. Wanna Cry has used an exploit - a piece of bug in the software - to take advantage of Microsoft Windows and take control of thousands of systems, and lock files. That's why it's called ransomware.
The attack is taking advantage of a vulnerability in computers running Microsoft Windows.
All it would take is for a new group of hackers to change the original malware code slightly to remove the "kill switch" and send it off into the world, using the same e-mail-based methods to infiltrate computer systems that the original attackers used, experts said. This one worked because of a "perfect storm" of conditions, including a known and highly unsafe security hole in Microsoft Windows, tardy users who didn't apply Microsoft's March software fix, and malware created to spread quickly once inside university, business or government networks.
Some hospitals were compelled to cancel treatments and appointments, and divert ambulances to other sites as authoroties try to deal with the situation. The country's banking system was also attacked, although no problems were detected, as was the railway system.
Anyone who hasn't updated their Windows PC recently.
That said, Microsoft can't shirk the blame entirely - it needs to reconsider its responsibility for users that work on older systems, particularly those across large networks that might avoid the sheer cost and scale of regular updating.
Ransomware is a program that gets into your computer, either by clicking on the wrong thing or downloading the wrong thing, and then it holds something you need to ransom. "While this protected newer Windows systems and computers that had enabled Windows Update to apply this latest update, many computers remained unpatched globally", Smith wrote. Install all Windows updates. 5.
A spokesman said: "Our understanding is that if that had been acted on it would have prevented [the malware attack]". Several Chinese government bodies, including police and traffic authorities, reported they had been impacted by the hack, according to posts on official microblogs. A 22-year old security researcher in the United Kingdom discovered a "kill-switch" to initially stop the spread of the attack.
Likewise, InfoTrust CEO, Dane Meah, also expects to see new variants of the WannaCry exploit to lead to a second wave of attempted attacks locally and further afield.
The full scale of the worldwide cyber attack that continues to disrupt the NHS may only become apparent when people return to work on Monday, experts have warned.
"This may be because some expensive hardware, such as magnetic resonance imaging scanners, can not be updated immediately, and in such instances, organisations will take steps to mitigate any risk, such as by isolating the device from the main network".
Senior security staff held another meeting in the White House Situation Room on Saturday, and the Federal Bureau of Investigation and National Security Agency were trying to identify the perpetrators of the massive cyber attack, said the official, who spoke on condition on anonymity to the news agency to discuss internal deliberations.
But some networks may have caught the malicious bug after workers went home, meaning the malware is already there, waiting for employees to power up their computers.