The insomnia ransomware group listed United Medical Doctors on its data leak site on 2026-04-09. Country: US Sector: Healthcare Domains named: www.unitedmd.com Claim as published on the leak site: United Medical Doctors (UMD) is an independent multi‑specialty medical‑surgical group with 70+ Southern California locations and 40+ specialties. They focus on high‑quality, compassionate care, patient satisfaction, process improvement, outpatient surgery, clinical research.