Hackers have been able to successfully infiltrate an external IT provider used by Australian military personnel.
It’s been reported the hack also impacted Australian Defence Department public servants.
A spokeswoman for Australian Defence Minister Richard Marles confirmed the breach had taken place on the ForceNet service.
However, it’s believed no personal data had been compromised or stolen.
In an email to all staff, the Defence secretary said the matter was being taken “very seriously”.
The attack happened earlier this month.
It comes as a number of other cyber attacks have wreaked havoc for many companies in recent weeks, including Medibank and Optus.
