Insight Hospital and Medical Center investigates cyberattack exposing patient and financial data

Insight Hospital and Medical Center, a nonprofit teaching and community hospital serving Chicago’s Near South Side, is investigating a cybersecurity incident that involved unauthorized access to its network between Aug. 22 and Sept. 11, 2025, potentially exposing sensitive personal and medical information.

The hospital detected unusual activity within its IT environment in September 2025 and launched a forensic investigation to determine the nature and scope of the intrusion. Security experts confirmed that an unauthorized individual accessed the network during the late August to early September time frame and may have viewed or acquired certain files stored within hospital systems.

The organization is conducting an ongoing review to identify the individuals affected and the exact information involved. Preliminary findings indicate that the compromised data may include names, dates of birth, Social Security numbers, driver’s license numbers, passport numbers, financial account information, treatment-related medical information, and health insurance details.

Notification letters will be mailed to affected individuals once the data review process is completed.

Two ransomware groups have publicly claimed responsibility for the attack. The LockBit5 cybercrime group listed Insight Hospital and Medical Center on its dark web data leak site on Dec. 4, 2025, alleging that it obtained nearly 200 gigabytes of medical data from the organization’s systems. Another group, known as Termite, later added the hospital to its own leak site and claimed to have exfiltrated approximately 360 gigabytes of data. The group posted stolen data online in late February 2026.

Insight Hospital and Medical Center operates from the historic campus formerly known as Mercy Hospital and Medical Center and serves the Bronzeville neighborhood and surrounding communities. The facility provides inpatient, outpatient, and emergency services and also maintains residency and medical training programs while partnering with community organizations to address public health and social care needs.