UnitedHealth Cites ‘Nation-State’ in Hack Disrupting Pharmacies

A cyberattack against a division of UnitedHealth Group Inc. has caused a nationwide outage of a computer network that’s used to transmit data between health-care providers and insurance companies, rendering some pharmacies unable to process prescriptions, according to the company and reports from affected organizations.

UnitedHealth found a “suspected nation-state associated cyber security threat actor” had access to subsidiary Change Healthcare’s systems on Feb. 21, prompting the company to disconnect them from other parties, the company said in a filing Thursday.

UnitedHealth, the country’s largest health insurer, said in a statement Thursday that the cyberattack and related “network interruption” only ...