University of Hawaiʻi Cancer Center Ransomware Breach Exposes Data of Up to 1.2 Million People
The University of Hawaiʻi confirmed that a ransomware attack against the UH Cancer Center’s Epidemiology Division led to the theft of sensitive data affecting up to ~1.2 million individuals. The intrusion occurred in August 2025, and the university began issuing notifications in late February, including letters to 87,493 participants in the Multiethnic Cohort (MEC) Study and additional outreach tied to roughly 900,000 discovered email addresses. UH stated the incident did not impact Cancer Center clinical trials operations, patient care, other Cancer Center divisions, or UH student records.
Disclosed exposed data includes research and registry-related files containing names and Social Security numbers, and in some cases driver’s license numbers and health information associated with the MEC Study (1993–1996) and other diet/cancer studies, as well as historical datasets sourced from state transportation and voter registration records (late 1990s/2000s). Reporting also indicates the affected records include SSN identifiers from historical driver’s license and voter registration data, expanding the potential impacted population beyond the MEC cohort to approximately 1.15 million additional individuals whose information may have been present in those datasets.
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