Australia is currently the target of a "sophisticated" cyber attack - and an unnamed foreign government is behind it.
Scott Morrison, the country's prime minister, says the attacks have targeted all levels of the government - as well as political organisations, essential service providers and operators of other critical infrastructure.
"We know it is a sophisticated state-based cyber actor because of the scale and nature of the targeting," he said at a news conference.
Mr Morrison has stopped short of naming the country responsible for this "malicious" activity, but warned: "There are not a large number of state-based actors that can engage in this type of activity."
He also stressed there is no evidence of a "large-scale" breach affecting people's personal information.
The prime minister said he is making the threat public to raise awareness - and said the frequency of attacks has increased "over many months".