After being stolen from one of the country's leading health insurers, hundreds of Australians' personal information has been shared online.
In addition to names, addresses, birthdates, and government ID numbers, some health claims data, including medical procedure history, was disclosed.
Last month, the information of 9.7 million Medibank clients was stolen.
Wednesday, however, a sample was released after the insurance refused to pay a ransom.
More information will be given soon, according to the group claiming responsibility.
It follows a series of prominent data breaches in Australia.
While millions of consumers had their data stolen, the most catastrophic breach, according to Medibank, involved approximately 500,000 customers whose confidential health information was stolen.
They stated that no credit card or financial information was obtained.
Medibank expressed regret for the situation and stated that it will work "around the clock" to notify affected customers.
"This is a criminal conduct intended to cause hurt and grief to our clients," stated chief executive David Koczkar.
We take our obligation to protect our customers seriously and stand ready to assist them.
In September, the Australian telecoms giant Optus was also targeted for extortion, following the theft of the personal information of approximately 10 million subscribers in what the firm termed a cyberattack.