Australian private and public sector organisations are currently being breached in what Prime Minister Scott Morrison says is a "sophisticated" cyber attack.
The attacks have targeted all levels of the Government, political organisations, essential service providers and operators of other critical infrastructure, Morrison said at a media briefing in Canberra.
While Morrison said Australia will not identify which country was responsible, senior Government sources have told the ABC they believe China is behind it.
"We know it is a sophisticated state-based cyber actor because of the scale and nature of the targeting," Morrison said.
"This attack is targeting Australian organisations across a range of sectors.
"Regrettably, this activity is not new."
In a statement to Newshub, New Zealand Minister responsible for the GCSB Andrew Little said NZ was not experiencing any such attack.
"We are not currently seeing malicious activity above the levels we would usually expect to see," he said. "We know that New Zealand organisations of national significance are also subject to malicious cyber activity, and our cyber security agencies are very alert to these threats."
Australia Defence Minister Linda Reynolds said advice showed no large-scale personal data breaches from the attack.
Morrison's public declaration was an attempt to raise the issue with those who could be targeted, an Australian Government source told Reuters.
Australia's chief cyber intelligence agency said its investigations have so far found no evidence that the actor attempted to be "disruptive or destructive" once within the host's network.
Morrison said he had spoken with UK Prime Minister Boris Johnson on Thursday about the issue, while briefings to other allies have also been conducted.
The revelation comes after Reuters reported Canberra had determined in March last year that China was responsible for a hacking attack on Australia's Parliament. Australia never publicly identified that source of the attack and China denied it was responsible.
A US security ally, Australia strained ties with its largest trading partner, China, by pushing for an international inquiry into the source and spread of COVID-19 that first emerged in the central Chinese city of Wuhan late last year.
Reuters / Newshub.