A number of Victorian hospitals have disconnected themselves from the internet in an attempt to quarantine a ransomware infection.
"The priority is to fix all affected systems and prevent any further compromise," the Victorian Department of Premier and Cabinet said on Tuesday morning.
"This isolation has led to the shutdown of some patient records [and] booking and management systems, which may impact on patient contact and scheduling. Where practical, hospitals are reverting to manual systems to maintain their services."
The department said the impacted hospitals were in the Gippsland Health Alliance and the South West Alliance of Rural Health.
See: Ransomware: 11 steps you should take to protect against disaster
Although the department said "there is no suggestion that personal patient information has been accessed", access to some systems have been blocked, including financial systems.
The Victorian government is working with the health services, police, and Australian Cyber Security Centre to fix the incident.
A recent ransomware incident on Demant, one of the world's largest manufacturers of hearing aids, is set to cost the company $95 million.
On the same day that Victorian health providers discovered the ransomware incident, the Australian Digital Health Agency (ADHA) announced an upgrade to My Health Record that would connect pathology and diagnostic imaging providers to the electronic health record.
My Health Record now holds 31 million clinical documents and in excess of 1.3 billion Medicare documents, ADHA said.
Private health providers have consistently been at the top of the Notifiable Data Breaches quarterly report from the Office of the Australian Information Commissioner.