New Zealand's central bank said it was investigating a breach of a third-party data system used to share and store the bank's sensitive data, Bloomberg and other news organizations said.
The attack at the Reserve Bank of New Zealand is significant and is likely to be another government trying to hack the bank, according to Dave Parry, professor of computer science at Auckland University.
Later Monday the bank released more details of the attack saying a file-sharing system provided by California cloud company Accellion, Inc. had been compromised.
Reserve Bank Gov. Adrian Orr said it had been advised by Accellion that the Reserve Bank had not been specifically targeted and that other users of the software were compromised.
Orr said the file-sharing software was used to share information with "external stakeholders" and the bank was continuing to "respond with urgency to the breach."
He said it would take time to determine the effects of the breach.
While the access has been contained, the extent and nature of the data potentially stolen is being analyzed and might have included personal and commercial information, Orr said in a statement issued Sunday.
"We're working closely with local and international cybersecurity experts and other authorities as part of our inquiry and response to this malicious attack," Orr said.
A number of organizations in New Zealand have been targeted by hackers in the past year - including the New Zealand Stock Exchange which had its systems rendered useless for almost a week in August.
The government sought the help of its intelligence agency and set in place new safety measures to help protect the stock exchange after the hacking that lasted for four days.
It isn't known what country was behind a cyberattack against New Zealand. New Zealand has mostly distanced itself from the trade dispute between China and Australia but has criticized China for a tweet targeting Australia in November.
China has yet to enforce trade sanctions against New Zealand, but Australia and New Zealand are close allies.
A representative of the NZCB declined to answer questions about the breach, The Associated Press reported.