Stewart Home & School announced a cybersecurity incident in April 2026 after discovering a credential-based ransomware attack that occurred in August 2025. The Sinobi ransomware group claimed responsibility for the attack.
The breach involved personal, financial, educational, and health-related data for 3,677 individuals. This data included full names, Social Security numbers, protected health information (diagnoses, medications, test results), financial details, health insurance information, and educational records. The school has stated that there is no evidence of misuse of the data, but highly sensitive information may have been compromised. Affected individuals, primarily clients in South Australia where the school's ICT systems were impacted, have been notified and offered 24 months of credit monitoring.
More details may emerge as the investigation continues, and official notices may still be delayed.