On Wednesday, hackers started publishing private medical records that they had stolen from a significant Australian health insurer who had previously declined to pay the group’s ransom demand.

A “sample” of data from roughly 9.7 million clients had been posted on a “dark web forum,” Medibank informed investors and clients.

Sensitive personal information posted anonymously early on Wednesday included names, birth dates, addresses, passport numbers, and details on medical claims.

More leaks, according to Medibank, are likely.

In a statement to the Australian Securities Exchange, the company said, “The files appear to be a sample of the data that we earlier determined was accessed by the criminal,”.

“We expect the criminal to continue to release files on the dark web.”

Previously, Medibank refused to pay a ransom to the hackers to stop them from leaking the data, arguing that doing so could encourage more crime and would not ensure the security of the data.

“Based on the extensive advice we have received from cybercrime experts, we believe there is only a limited chance paying a ransom would ensure the return of our customers’ data and prevent it from being published,” David Koczkar, the CEO of Medibank, said.

The exposed information was published on a forum accessible only through dark web browsers.

“We’ll continue posting data partially,” the purported hackers said on the forum. 

“Looking back that data is not very understandable format, we’ll take some time to sort it out.”

A “criminal or criminal groups” may be operating outside of Australia, according to AFP Assistant Commissioner for Cyber Command Justine Gough.

Stephen Jones, the assistant treasurer for Australia, called them “scumbags” and “crooks.”

“We shouldn’t be giving in to these fraudsters,” The man spoke to Sky News Australia.

“The moment we fold it sends a green light to scumbags like them throughout the world that Australia is a soft target.”

The security breach has already reduced Medibank’s market value by hundreds of millions of dollars, with the stock down more than 20% since October.