Ohio-based healthcare network Kettering Health has confirmed that it was the target of a ransomware attack carried out by the Interlock group in May, resulting in a major data breach.
The non-profit system, which runs 14 medical centers and over 120 outpatient facilities, reported that attackers stole 941 gigabytes of data from its network.
In a statement released Thursday, Kettering Health said the breach has been contained, and all compromised systems have been secured. The healthcare provider, which employs more than 15,000 staff, including 1,800+ physicians, assured that enhanced security measures like network segmentation, updated access controls, and continuous monitoring have been put in place.
“The tools and persistence mechanisms used by the third-party group have been eradicated,” the organization said, adding that both internal and external cybersecurity experts conducted a full review of its systems.
The attack, which occurred on May 20, forced Kettering Health to revert to paper records due to a network outage. The incident disrupted charting systems, call centers, and some patient services, even leading to canceled elective procedures. However, emergency rooms and clinics remained open throughout the incident.
This week, Interlock claimed responsibility and posted samples of the stolen data on its leak site. According to the group, the stolen files include sensitive patient information, pharmacy and blood bank records, payroll data, identity documents like passports, and even police personnel files.
Interlock, an emerging ransomware group active since September, has been linked to multiple global cyberattacks, with a growing focus on healthcare targets. The gang has also used deceptive IT tools and custom malware, including a remote access trojan named NodeSnake, in recent campaigns. Earlier, it also claimed responsibility for breaching DaVita, a major U.S. kidney care provider.
If this article helped you, please consider supporting our work. Every small contribution keeps Abijita.com independent and running.
Kettering Health has since restored its electronic health records system and is working to bring its MyChart platform and call center fully back online.
