Officials are Humber River Hospital are scrambling to restore their computer systems after the facility in Toronto’s north end was the target of a ransomware attack.

A statement on the hospital’s website posted earlier in the week said during the early hours of Monday, it experienced a so-called “zero day ransomware of a new malware variant,” forcing staff to declare a code grey (a loss of essential services).

While the emergency department was still operational, some clinics were cancelled and ambulances were redirected.

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“Since our systems are constantly updated (most recent patching June 13, 2021) and monitored this was discovered almost immediately and all IT systems were shut down, including our patient health records system,” the statement said, adding while no confidential information was breaking some files were corrupted.

“We have over 5,000 computers, 800 of which are servers, (and) each will be restarted manually. [The repair patch] will be added to each computer and then each system recovered as required.”

Security engineer Kellman Mengu said ransomware attacks, which involves taking data, files and systems hostage remotely and often for money, are common and can cause massive disruptions for hospital operations.

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“We have automated a lot of things in our world and we are now heavily dependent on the technology,” he said.

“I’m willing to bet there aren’t backup paper records easily accessible. Things like patient history and understanding what they have gone through the past for the doctors is critical for them to be able to make medical decisions.

“It’s not just patient records — it’s things like…