Healthcare Cybersecurity

Health technology company TriZetto, a Cognizant subsidiary that processes insurance-eligibility checks for doctors and hospitals, has confirmed that hackers stole personal and medical information on more than 3.4 million people in a breach of its systems. The firm says attackers accessed insurance eligibility transaction reports that can include names, dates of birth, home addresses, Social Security numbers, insurance details, provider names and demographic data linked to medical records. TriZetto detected the breach on Oct. 2, 2025, but later found the intrusion may have begun as early as November 2024, meaning hackers may have been inside its network for nearly a year before discovery. The company’s systems help support healthcare operations tied to about 200 million people through more than 875,000 providers nationwide, and organizations such as nonprofit tech group OCHIN and unnamed California providers have already acknowledged that their patients’ data were swept up in the attack. The incident underscores the growing risk posed by attacks on little-known but deeply embedded health-IT middlemen, and it is fueling fresh questions from cybersecurity experts about how long adversaries can lurk in critical healthcare systems before anyone notices.