Outdated computer networks across federal departments leave Australia's essential public services open to a rapidly accelerating wave of next-generation hacker threats. Subscribe now for unlimited access. or signup to continue reading This structural weakness triggered urgent warnings from leading cyber security experts. They warned although replacing these legacy systems was entirely possible, the transition required immediate attention and funding. Australian Information Security Association (AISA) board member Scarlett McDermott used a simple analogy to describe the huge technology gap facing these systems. "Trying to perform modern security processes on a legacy system is kind of like trying to plug your 1992 Volvo into an electric car charger, sometimes they're just not compatible," Mrs McDermott said. Old networks became so tangled up in daily office tasks over the years that replacing them required a significant shift in how the government operates every day, she said. The 2025 Commonwealth Cyber Security Posture showed 59 per cent of agencies attributed the stalled rollout of essential security defences to their reliance on outdated technology, which lacked funding for a viable replacement. A joint Mandala and Microsoft report found retiring the federal government's outdated technology could save Australia about $1.4 billion annually. The technological upkeep made up to 40 per cent of their tech budgets to keep the systems alive, ignoring modern alternatives that cost about a quarter less to run. AISA director Dr Rajiv Shah said the vulnerability of government agencies to future high-tech disruptions stemmed from unmaintained, homemade software. Many departments ran programs that changed hands so many times over the years that "almost no one really knows how they work", he said. Dr Shah, a quantum physics expert, said the original developers and designers of these systems "probably retired 10 years ago", leaving behind poor instructions and very limited internal understanding of how