Prime Minister John Key has requested a full briefing from the Government's cyber-spies on an attempted hack of NIWA's supercomputer.
He confirmed the attack appeared to originate from China. But stressed this may have been a bid to obscure the true location.
Fairfax Media revealed on Saturday that the $12.7m system, known as Fitzroy, was targeted late last week.
Key has asked for a briefing from the National Cyber Security centre, based at the Government Communications Security Bureau. But he was "cautious" about speculating about who was behind the hit.
"Look it does concern me," he said "They [hackers] often hide their identity through the IP addresses that they use. While sometimes they might look as though it is obvious which country they are coming from, they can just be a host for an entity that's actually completely different from the one you see."
It was "very, very difficult" to know if the intention was espionage.
Asked what the motive would be for targeting the Crown research institute, Key said: "It's the very question I asked my guys. I just simply don't have an answer.''
The number of cyber attacks registered in New Zealand grew from 134 in 2012, to 219 in 2013. About 70 per cent of attacks were on the private sector, Key said.
''It's not either wise or appropriate for me to comment about the particular companies that have been attacked...but what is certainly true is that there are a number of entities who are making quite sophisticated, robust attempts to break into the systems of some very large private sector entities. And there would be a range of reasons why they are trying to do that...for trade, intellectual property those companies have, understand a bit about their clients, understand a bit about their data systems.''
New Zealand has ''a lot" to lose from online attacks, he added. "Cyber is the new frontier, because so much is done on people's computer systems."
The US recently identified Chinese military hackers it accused of stealing trade secrets from America's largest companies.
Key may raise the problem with President Barack Obama on an upcoming visit to the White House. But he won't be talking to the Chinese government about it. "I think in the first instance we will try and get better information."
The NIWA hacking was unsuccessful and the systems went back online on Saturday, a spokeswoman confirmed today.