In November, hackers demanded that Australian insurance giant Medibank pay $9.7 million so that the records were not published on the internet, or $1 for each of the affected customers, including Prime Minister Anthony Albanian.

Medibank refused to pay at the behest of the federal government, which at the height of the crisis had considered making it illegal for hacked companies to deliver ransoms.

The hackers announced Thursday morning that they had uploaded the latest data, deliberately coinciding with the International Computer Security Day.

"Happy Cybersecurity Day," they wrote.

"File added complete. Case closed."

The stolen data bundles began appearing on November 9 on a dark web forum - which cannot be found using regular browsers.

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

Medibank said on Thursday that the latest publication was "incomplete and difficult to understand" -- an indication that hackers may have lost motivation after the possibility of collecting a ransom was taken off the table.

“While our investigation continues, there are currently no signs that any financial or banking data has been taken,” Medibank said in a statement.

In November, Australian Federal Police Commissioner Reece Kershaw blamed the attack on Medibank on "cybercriminals" based in Russia.

Cybersecurity analysts have suggested they may be linked to Russian hacker group REvil.

Australian government ministers have branded the hackers "garbage" or "sleazy criminals".

© 2022 AFP