In the latest Australian Signals Directorate annual report, director-general Rachel Noble laid out the challenges facing the country in the cyber security space.

"Cybercrime continued to be a pervasive and endemic threat to Australia's economic and social prosperity," she said.

"Ransomware is one of the most significant cybercrime threats Australian organisations faced, with modern ransomware attacks increasingly sequenced and orchestrated."

Ms Noble said cybercriminals followed the money and were attracted to Australia because of its wealth, high levels of online connectivity and increasing demand for delivery of services through online channels.

These factors made the country a profitable target for cybercriminals.

In the report, Ms Noble notes Australia was attacked by a "range of actors" through persistent cyber operations.

The agency observed an increase in the speed "malicious actors have researched and then pivoted to exploit publicly released vulnerabilities".

Australian companies have been dealing with the fallout of major data breaches, with the Optus and Medibank hacks some of the largest on record.

The Russian criminals behind the Medibank hack dumped a fifth tranche of sensitive information on the dark web on Sunday, after the health insurer refused to pay a $US10 million ($A15 million) ransom.

The scale of the breaches prompted the Albanese government to introduce tough new penalties for businesses that fail to adequately protect the data of their customers.

Australian Associated Press