Better cybersecurity for Medical Imaging Devices (MIDs)

“CTs and MRI systems are not well-designed to thwart attacks,” says lead author Dr. Nir Nissim, who simulates MID cyberattacks together with his MSc student Tom Mahler. Tom is part of the Malware Lab’s team which includes 17 outstanding research students, and conducted the research under the supervision of Dr. Nir Nissim,  Prof. Yuval Elovici, director of Cyber@BGU and Prof. Yuval Shahar, director of BGU’s Medical Informatics Research Center.

“The MID development process, from concept to market, takes three to seven years. Cyber threats can change significantly over that period, which leaves medical imaging devices highly vulnerable,” says Mahler.

The study, conducted in collaboration with Clalit Health Services, Israel’s largest health maintenance organization, included a comprehensive risk analysis survey based on the “Confidentiality, Integrity and Availability” risk model, which addresses information security within an organization.

Researchers targeted a range of vulnerabilities and potential attacks aimed at MIDs, medical and imaging information systems and medical protocols and standards. While they discovered vulnerabilities in many of the systems, they found that CT devices face the greatest risk of cyberattack due to their pivotal role in acute care imaging. Simulated cyberattacks revealed four dangerous outcomes:

1.  Disruption of scan configuration files − By manipulating these files, an attacker can install malware that controls the entire CT operation and puts a patient at great risk.

2.  Mechanical MID motor disruption – Medical imaging devices have several components with mechanical motors, including the bed, scanner and rotation motors, which receive instructions from a control unit, such as the host computer (PC). If malware infects the host computer, an attack on the motors can damage the device and injure a patient.

3.  Image results disruption − Because a CT sends scanned results connected to a patient’s medical record via a host computer, an attack on that computer could disrupt the results, requiring a second exam. A more sophisticated attack may alter results or mix up a transmission and connect images to the wrong patient.

4.  Ransomware − This malware encrypts a victim’s files and demands a ransom to decrypt them. The WannaCry attack, which affected more than 200,000 devices in more than 150 nations in May 2017, directly infected tens of thousands of U.K. and U.S. hospital devices, including MRIs.

“In cases where even a small delay can be fatal, or where a dangerous tumor is removed or erroneously added to an image, a cyberattack can be fatal,” says Mahler. “However, strict regulations make it difficult to conduct basic updates on medical PCs, and merely installing anti-virus protection is insufficient for preventing cyberattacks.”

BGU Malware Lab researchers are working on new techniques to secure CT devices based on machine learning methods. The machine-learning algorithm analyzes the profile of the patient being scanned, as well as many additional operational parameters of the CT itself, and produces an anomaly detection model based on a clean CT machine. Once the machine is infected, the detection model can identify the change in its behavior and its operational parameters and alert the administrator accordingly.

In future research, Dr. Nissim and his team will conduct nearly two dozen attacks to further uncover vulnerabilities and propose solutions to address them. They are interested in collaborating with imaging manufacturers or hospital systems for in situ evaluation.

“As the Israeli academic leader in cyber security research, we partnered with Israel Defense to help create the Cybertech conferences four years ago,” says BGU President Prof. Rivka Carmi. “Cybertech is the preeminent forum in Israel to showcase our success in cyber research, innovation and commercialization and we will continue to play a leadership role in that arena.”

— Read more in Nir Nissim et al., “Know Your Enemy: Characteristics of Cyber-Attacks on Medical Imaging Devices,” arXiv:1801.05583 [cs.CR] (17 January 2018)