Kingsbrook Jewish Medical Center, one of the hospitals hit with a cyberattack.
New York CNN  — 

A network of three hospitals in Brooklyn, New York, has had to work off paper charts for weeks following a cyberattack on its computer systems in late November, the hospital group’s chief executive told CNN Monday.

The hack affected “clinical applications,” including “those used for imaging and other critical services,” but many of those applications have been restored, One Brooklyn Health CEO LaRay Brown said in an email.

It’s an example of how hacking incidents have continued to hamper hospitals as the coronavirus pandemic drags on — and of how recovering from the hacks can be painstaking and disruptive for hospital staff.

One Brooklyn Health operates Brookdale University Hospital Medical Center, Interfaith Medical Center and Kingsbrook Jewish Medical Center.

One staff member at Brookdale told the New York Times that, because of the hack, diagnostic imaging at the medical center had to be sent out to a third party provider rather than done in-house.

“No patients were adversely effected,” Brown told CNN in an email Monday, adding that the hospitals remain open to patients. “We continue to provide care for our patients using downtime procedures for which our clinicians and administrators have been trained.”

More than 80% of the computer workstations that One Brooklyn Health doctors and staff use to support hospital operations have been restored, Brown said. Hospital administrators have begun putting some clinical data into patients’ electronic medical records, she added.

Brown did not answer questions about whether One Brooklyn Health was dealing with a ransomware attack, which locks up computer systems until a ransom is paid. But plenty of other hospitals across the country have had to deal with such extortion attempts.

One IT administrator at a 100-bed hospital in Florida