INSPECTING ARCHIVED INTELLIGENCE (OUTDATED VERSION).

Quest Diagnostics Experiences Cyber Breach Affecting Certain Patient Records

| 2026-10-23 08:25 HIGH HIGH DATA BREACH
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Executive Summary
AI-generated
Quest Diagnostics reported a cyber breach affecting 'certain patient records' on October 23, 2026. The New Jersey-based company discovered the hack and notified federal law enforcement, working with external cybersecurity experts to assist in its response. The targeted sector is health, specifically lab services managed by Quanum Lab Services. This incident occurred after a similar breach in 2016 exposed data of about 34,000 people and another breach in 2019 affecting approximately 11.9 million Quest patients. The company has previously experienced unauthorized access to patient records, including a notable exposure in 2016.
Technical Mitigations AI-generated
• Reset credentials and API keys that may have been exposed, and review access logs for the affected accounts or integrations.
Intelligence Metadata
Actors / Malware / CVEs / Campaigns
Target & Sectors
JE
healthhealth
Incident Timeline
‎2026/10/23
Threat actors gained unauthorized access to Quest Diagnostics' Quanum Lab Services Manager platform.
organisation Quest Diagnostics
Quest Diagnostics Reports Cyber Breach Affecting ‘Certain Patient Records’.
organisation Quanum Lab Services
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.
organisation American Medical Collection Agency
And in 2019, other personal information belonging to about 11.9 million Quest patients was affected after a separate hack at American Medical Collection Agency, a billing collections service provider.
organisation PHP
Urgency erupted this week , after an AI-assisted discovery of vulnerabilities in a programming language called PHP, which is vital to 70% of websites globally.
organisation The Associated Press
But based on the company’s investigation, Quest Diagnostics confirmed to The Associated Press Thursday that its cyber breach was not related to the PHP issue.
Intelligence Sources
SecurityWeek 2026-10-23