Encrypt medical imaging: Malware could add or remove cancerous nodes in CT scans

Security researchers in Israel have developed malware that can add realistic-looking but entirely fake growths to CT and MRI scans or hide real cancerous nodules that would be detected by the medical imagining equipment. The software, designed by experts at the Ben Gurion University Cyber Security Research Center, was created to highlight the lax security protecting diagnostic tools and hospital networks that handle sensitive information.

To test out how effective the attack could be, the researchers conducted a blind study that asked radiologists to diagnose conditions based on CT lung scans—some of which were altered using the malware. When presented with scans that featured fake cancers nodules, the radiologists came back with a cancer diagnosis 99 percent of the time. When the malware was used to hide real cancer nodules, radiologists issued a clean bill of health 94 percent of the time.

One of the researchers, Yisroel Mirsky, told the Post that hospitals are vulnerable to the attacks because they tend to be more concerned about protecting data shared between hospitals and with other doctors, ignoring “what happens within the hospital system itself.”

To prevent malware from altering CT and MRI scans, hospitals need to install end-to-end encryption across its picture archiving and communication system network. Hospitals also must digitally sign all images, according to the Post.

Studies have proven malware-attacked CT scans are an immediate threat. In one blind study that involved real CT lung scans, 70 of them were altered by malware. Three skilled radiologists were tricked into misdiagnoses nearly every time, the Post reported.

After radiologists were told scans were fabricated by malware and given a second set of scans, they were still tricked 60 percent of the time. In scans that removed cancerous nodules, radiologists failed to diagnose actual sick patients 87 percent of the time.

Although these studies focused on lung cancer scans, the malware can attack CT scans for brain tumors, heart disease, blood clots, spinal injuries, bone fractures, ligament injuries and arthritis.