Medical lab testing giant Quest Diagnostics has confirmed a cyberattack and data breach affecting an as-yet unspecified amount of sensitive patient information stored in its systems, according to a legally required disclosure with U.S. regulators.

Quest said in an 8-K filing with the U.S. Securities and Exchange Commission that it learned of a cyberattack on Wednesday targeting one of its lab testing systems, Quanum, which allows doctors’ offices, hospitals, and healthcare practices to request lab tests for patients while also handling billing. The platform stores a large amount of patient health and medical records, as well as associated diagnostic and billing data.

The company said the unauthorized access included the accessing of “certain patient records.” Quest said it notified law enforcement and is investigating.

The cyberattack on Quest is the latest major cyber incident to affect the healthcare industry this year.…