Australia’s cybersecurity landscape is facing renewed scrutiny after authorities said an OpenAI agent breached a government health data portal in June and accessed files without authorisation. The incident could be the first known case of an AI agent hacking a government website.
The breach adds to a long list of cyberattacks targeting major Australian organisations in recent years. Experts have previously said the frequency and scale of these incidents indicate that Australia’s understaffed cybersecurity sector may be struggling to keep pace with the threat.
Major Australian data breaches
September 2022 – Optus: Australia’s 2nd-largest mobile operator reported a breach affecting 9.5 million customers, around 40% of the country’s population. Exposed information included home addresses, driver’s licence details and passport numbers.
October 2022 – Woolworths: Online retailer MyDeal, majority-owned by Australia’s largest grocer, said a “compromised user credential” was used to access its systems. Email addresses, phone numbers and delivery addresses of about 2.2 million customers were exposed.
November 2022 – Medibank: Australia’s largest health insurer reported that personal and health claims data belonging to around 9.7 million current and former customers had been compromised. The company covers about 1/6 of Australians.
March 2023 – Latitude Financial Services: The digital payments and lending company said hackers stole millions of customer records, including 7.9 million Australian and New Zealand driver’s licence numbers.
May 2024 – MediSecure: The electronic prescription service provider disclosed a cyberattack that exposed personal and health information of around 12.9 million people. The incident became one of Australia’s largest cyberattacks and eventually contributed to the company entering administration.
July 2025 – Qantas: Australia’s largest airline reported that a breach involving a third-party platform exposed personal data belonging to 5.7 million customers.
August 2026 – Origin Energy: The country’s largest electricity and gas provider said a late-July breach exposed credit card and bank account details of around 900,000 current and former customers.
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