Medibank, one of the country's largest private health insurance companies, admitted this week that hackers had been able to access the personal data of its approximately 9.7 million customers and former customers, including Prime Minister Anthony Albanese.

After publishing a first "sample" of this data on Wednesday, the hackers published a second on Thursday on a "dark web" forum - which cannot be found using traditional browsers.

It contained particularly personal information on hundreds of people.

The first information disclosed appeared to have been selected to cause significant harm, targeting people being treated for drug addiction, sexually transmitted infections or pregnancy terminations.

“(We have) added one more file, abortions.csv,” the anonymous hackers wrote, before detailing their ransom demand.

"It is 10 million US dollars. We can make a discount (...) 1 dollar = 1 customer", they specify on this forum.

The insurer has so far refused to pay the hackers.

"Profit and Greed"

The cyberattack on Medibank, along with the September hack of the country's second-largest mobile operator, Optus, raise questions about Australia's ability to resist cybercriminals.

Dennis Desmond, a former FBI and US intelligence agent, argues that Australia is no less armed "than any other high-value target or western country."

"It's very unfortunate, but I don't think Australia is more vulnerable than any other developed western nation," the expert told AFP.

According to Desmond, profit-driven hackers typically seek to attack companies that hold valuable data.

"Health data is a prime target and data on identifiable people is of great value (...) Typically, profit and greed are the main motivations."

"Shabby"

Medibank boss David Koczkar called the hackers' blackmail "shameful".

"The use of personal information for the purpose of extorting (money) constitutes a malicious (offence)," he said, adding "it is an attack on the most vulnerable members of our community".

The group responsible for this computer attack appears to be putting pressure on Medibank by searching the insurer's files for personal information that could cause the most harm possible.

Within the first leaked data, the victims were divided into a list of "good guys" and "bad guys".

Several people on the "villains" list were associated with numerical codes linking them to drug addiction, alcoholism and HIV.

A file included for example the indication "p_diag: F122".

F122 is the code for "cannabis dependence" according to the International Classification of Diseases published by the World Health Organization.

Names, passport numbers, dates of birth and addresses were also included in this data.

Australian Home Secretary Clare O'Neil has called these hackers "despicable criminals".

© 2022 AFP