Medical laboratory operator Quest Diagnostics said it learned of a cyber breach of one of its systems this week, likely compromising some records for patients. In a Thursday regulatory filing, Quest Diagnostics reported “unauthorized access” to its Quanum Lab Services Manager, a platform where certain clients can place test orders and receive or look up their results. The company said it discovered the hack on Wednesday and notified federal law enforcement. How many patients and which particular records have been affected is still unknown. Quest Diagnostics said it believes “certain patient records” were accessed in the breach, but that the...