The weekend's cyber attack hit 200,000 victims in at least 150 countries, and that number could grow when people return to work on Monday, the head of the European Union's police agency says.
Cyber security experts say the spread of the virus dubbed WannaCry - ransomware which locked up computers in car factories, hospitals, shops and schools in several countries - has slowed, but that any respite might be brief.
- WannaCry ransomware attack: Killswitch activated, but danger not over
- WannaCry ransomware attack: How to protect yourself
Prime Minister Bill English says there have been no cases of the virus reported to New Zealand's cyber security authorities - though it has been the weekend.
"New Zealand's pretty well set-up to deal with attacks," he told The AM Show on Monday.
"We've got a national cyber security centre, we've got an organisation just started up… to make sure people know where to report. The advice from that system is there's no sign of it in New Zealand."
Europol director Rob Wainwright told ITV's the attack was unique in that the ransomware was used in combination with "a worm functionality" so the infection spread automatically.
"The global reach is unprecedented. The latest count is over 200,000 victims in at least 150 countries, and those victims, many of those will be businesses, including large corporations," he said.
"At the moment, we are in the face of an escalating threat. The numbers are going up; I am worried about how the numbers will continue to grow when people go to work and turn (on) their machines on Monday morning."
He said Europol and other agencies did not yet know who was behind the attack but "normally it is criminally minded and that is our first working theory for obvious reasons".
"Of course there are amounts that are being demanded, in this case relatively small amounts - US$300 rising to US$600 if you don't pay within three days," he said.
"[There have been] remarkably few payments so far that we've noticed as we are tracking this, so most people are not paying this, so there isn't a lot of money being made by criminal organisations so far."
Mr English says it could be difficult to find the perpetrators.
"If everyone knew [who they were], it would be easy to shut down. Just go knock on their door and pull the plug on their computers."
NHS underfunded to handle attacks?
Wainwright said Europol had been concerned about cyber security in the healthcare sector, which deals with a lot of sensitive data, but declined to comment on whether Britain's National Health Service had been adequately funded.
British Defence minister Michael Fallon told the BBC the government under Prime Minister Theresa May was spending around 50 million pounds on improving the computer systems in the NHS after warning the service that it needed to reduce its exposure to "the weakest system, the Windows XP".
"The NHS was not particularly targeted. There were the same attacks applied to Nissan on Friday and in other areas of the economy and indeed around the world," Fallon said.
"But let me just assure you, we are spending money on strengthening the cyber defence of our hospital system."
US President Donald Trump has ordered his homeland security adviser, Tom Bossert, to hold an emergency meeting to assess the threat, a senior administration official told Reuters.
The meeting was ordered on Friday (US time) as the global cyber breach unfolded.
Senior security staff held another meeting in the White House Situation Room on Saturday, and the FBI 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 discuss internal deliberations.
Reuters / Newshub.