UnitedHealth Group said on Monday that hackers stole health and personal data of potentially a “substantial proportion” of Americans from its systems in February, as the largest U.S. health insurer scrambles to contain the damage.
The intrusion at its Change Healthcare unit, which processes about 50 percent of U.S. medical claims, was one of the worst hacks to hit American healthcare and caused widespread disruption in payment to doctors and health facilities.
