Australia’s legacy systems were already a cyber risk. AI agents are raising the stakes

Australian government agencies face a cybersecurity risk stemming from the widespread use of outdated legacy technology, according to the Australian Signals Directorate. In 2025, 59% of government entities reported that legacy systems hindered their ability to implement critical cybersecurity measures. Legacy systems, defined as older hardware or software no longer supported by manufacturers or unable to meet current security requirements, pose a challenge not only technically but also due to issues with governance, responsibility, funding, and the availability of viable replacements.

Australia's vulnerability to AI-boosted cyber threats is enhanced by its widespread adoption of digital systems, perceived wealth, and patchy cyber defenses. Personal, financial, health, research, and proprietary data held by Australian governments and organizations make the country an attractive target for cybercriminals. AI agents contribute to this heightened risk, enabling cybercriminals and state-sponsored attackers to find vulnerabilities, analyze code, and exploit systems more rapidly.

AI agents have the capability to independently identify vulnerabilities, plan actions, use tools, interact with external systems, and adapt when encountering obstacles, as demonstrated in a recent Medicare incident in Australia. While AI does not create vulnerabilities in aging systems, it can change how quickly, persistently, and autonomously those vulnerabilities can be discovered and acted upon.

Governments and organizations hosting critical data must take steps to reduce AI agents' vulnerabilities. This includes identifying and isolating legacy systems, monitoring them closely, and potentially accepting residual risk for critical systems. Organizations using AI agents must also control what the agents can see, access, and do, implementing minimal access privileges, restricted permissions, strong authentication, monitoring, and human oversight for riskier actions. Audit trails should be maintained to track agent behavior and ensure accountability.