The majority of the attacks targeted Russia, Ukraine and Taiwan.
Hundreds of hospitals and clinics in the British National Health Service were infected Friday, forcing them to send patients to other facilities. Security experts say this attack should wake up every corporate board room and legislative chamber around the globe.
"Ever since the cyber attack began, Trust staff have responded magnificently to this unprecedented situation and have rallied round to help where needed".
Cybersecurity officials in Britain have applauded MalwareTech for helping halt the global attack. The ransomware was created to repeatedly contact an unregistered domain in its code.
A United Kingdom security researcher has told the BBC how he "accidentally" halted the spread of the malicious ransomware that has affected hundreds of organisations, including the UK's NHS.
He added: 'We have stopped this one, but there will be another one coming and it will not be stoppable by us.
However, a hacker could change the code to remove the domain and try the ransomware attack again. "They are processing a lot of sensitive data".
Other targets in Europe included Telefónica, the Spanish telecom giant; the French carmaker Renault; and a local authority in Sweden, which said about 70 computers were infected.
Mr Wainwright said what was unique about the attack was that the ransomware was used in combination with "a worm functionality" so the infection spread automatically.
The head of the European Union police agency said on Sunday the cyber assault hit 200,000 victims in at least 150 countries and that number will grow when people return to work on Monday.
European police agency Europol said it was working to support countries, saying the malware attack was at an "unprecedented level and requires worldwide investigation".
A ransomware program that locks the users computer and gives instructionson how to pay the ransom.
Hacking group or groups were yet to claim responsibility for the attack.
Microsoft did release a patch to fix the issue in mid-March, so organisations and individuals who did not update their systems are at risk.
Victims were asked for payment of $300 (275 euros) in the virtual currency Bitcoin.
On Saturday, experts said it appeared that the ransomware had made just over $20,000, although they expected that number to pop when people went back into the office Monday. The NHS said in a statement on Saturday that there was no evidence that patient information had been compromised.
"Once inside the system, the attackers install a rootkit, which enables them to download the software to encrypt the data".
MalwareTech said he bought the domain because his company tracks botnets and by registering these domains they can get an insight into how the botnet is spreading. "We've seen huge investments cuts in the infrastructure of the NHS", he said. "So I picked it up not knowing what it did at the time".
His procedure is being rescheduled within the next two weeks.
"The problem is the larger organizations are still running on old, no longer supported operating systems", said Lawrence Abrams, a New York-based blogger who runs BleepingComputer.com.
First, there was a highly unsafe security hole in Microsoft Windows, which became known after hackers leaked tools that were apparently created by the U.S. National Security Agency to exploit the hole.
Exercise caution before clicking on an email link from an unknown or potentially disguised source.
So just what can you do to protect your business from this malware, and other pieces of malicious software that are doing the rounds? Here's how to turn automatic updates on. Germany's national railway says that it was among the organizations affected by the global cyberattack but there was no impact on train services.
Security experts said that they were not sure how many victims would pay the ransoms, or if access to computers was being restored after such payments.
Russia's interior ministry said some of its computers had been hit by a "virus attack" and that efforts were underway to destroy it.
No one has yet identified the culprit.
"I don't think it's to do with that preparedness".
Europol provides free decryption downloads for most ransomware already detected, though not yet for this particular attack.