Five southwestern Ontario hospitals, supported by the IT services of TransForm Shared Service Organization, experienced significant disruptions due to a cyberattack. This incident led to the delay of medical procedures, including a crucial cardioversion, and left some patients waiting for extended periods, or even canceling treatments altogether. The hospitals were forced to revert to paper records as their online services, covering patient records and email communication, had been rendered inaccessible since Monday morning. The attack's extent necessitated the postponement of scheduled care and a plea for non-emergency patients to seek alternatives, highlighting the severe impact on hospital operations and patient care.

A cyberattack that affected five hospitals in Southwest Ontario prompted Michael Garron Hospital to disclose a data security incident. Patient records and various internet services were impacted by the attacks on Windsor Regional Hospital, Erie Shores HealthCare, Hôtel-Dieu Grace Healthcare, Bluewater Health, and the Chatham-Kent Health Alliance. All of these hospitals use the same IT vendor, and the Ministry of Health has confirmed the vulnerability that affected them. The ministry is convinced that TransForm SSO has and continues to take proper steps in response to this event.