Quest Diagnostics reports cyber breach affecting patient data

Quest Diagnostics announced that it experienced a cybersecurity breach that may have exposed patient records. In a filing to shareholders, the company said it discovered unauthorized access on Wednesday to the Quanum Lab Services Manager, a platform used by doctors and other health-care professionals to order tests and view results. The firm responded by pausing access to the affected system and also suspended several additional tools for health-care providers, even though those tools were not believed to be compromised, citing an "abundance of caution."

The company is investigating the incident and working with security experts to assess the scope of the breach and to strengthen its defenses.