2024 Ascension — Black Basta ransomware; 5.6M patients and employees
Data compromised
Personal, financial, insurance, and health information for patients and employees
Technical writeup
Ascension, one of the largest U.S. Catholic healthcare systems, suffered a May 2024 Black Basta ransomware attack that disrupted electronic health records nationwide—forcing paper charting, pausing elective procedures, and redirecting ambulances from affected facilities. The organization later notified almost 5.6 million patients and employees that personal, financial, insurance, and health information was stolen. This incident is separate from Ascension’s December 2024 third-party Cleo partner breach affecting 437,329 individuals.
Root cause
Black Basta ransomware; network intrusion forced EHR outages and ambulance diversions