Quest Diagnostics admits patient records stolen from Quanum platform
The lab testing giant filed a regulator notice confirming hackers accessed the system used by half a million clinicians.
By Sarah Montgomery ·
Doctors, hospitals, and clinics across North America rely on Quanum to order tests and process billing. On Wednesday, Quest Diagnostics told U.S. regulators that hackers broke into that system and took patient records. The company, one of the largest medical lab testers in the country, confirmed the breach in a mandatory 8-K filing with the Securities and Exchange Commission.
The filing states that the unauthorized access included specific patient records. Quest said it alerted law enforcement and began an internal investigation. A separate security notice on the company’s website clarified that protected health information was taken. The document lists personal information and patient records as compromised data. The company is still determining exactly which types of data were stolen.
The security notice is difficult to find. The webpage contains hidden code that instructs search engines not to index it. This technical choice keeps the page out of standard search results, making it harder for affected patients to discover the alert. A Quest spokesperson, Amanda Rivera, did not answer questions from reporters and directed them to the online notice.
The scope of the damage remains unclear. Quest has not said how many patients or healthcare customers were affected. It has not disclosed when the breach started. The company has not reported any contact from hackers demanding a ransom. It is also unknown whether the attackers have published any of the stolen data.
The exposure could be large. Quest’s marketing materials state that approximately 500,000 clinicians use Quanum across thousands of locations. A 2026 case study on the company’s website describes one health system with over 6 million patients. That single system can hold hundreds of millions of medical documents and charts.
This incident follows a year of major cyberattacks on the healthcare sector. In March, Stryker suffered mass wiping of employee devices. In August, Boston Scientific’s network went offline for weeks, causing global disruption. Other large breaches hit CareCloud, Craneware, and McKesson this year.
This is the second major data breach for Quest in a decade. In 2019, the company lost 11.9 million patient records after an attack on a third-party billing firm. The current breach marks the latest disruption in a sector where health tech firms face frequent financial threats.
