Seattle-based Fred Hutchinson Cancer Center took its IT systems down following a Thanksgiving-week cyberattack, the Seattle Times reported Dec. 1.
Fred Hutch went offline after discovering "suspicious activity" on its clinical network and remained that way Dec. 1, according to the story.
"We're still assessing what the potential impact could be to patients and employees," a health system spokesperson told the news outlet. "We have forensic teams who are assessing the level of data compromised and, as we know more, we’ll be able to alert folks as quickly as we possibly can."
Fred Hutch's clinics remained open, and its MyChart patient portal was still operational, the Times reported.
"Based on the information available, it appears a criminal group outside the U.S. is responsible," the spokesperson told Becker's. "Fred Hutch notified federal law enforcement and continues to provide them with information to support their investigation."
Hackers also attacked Ardent Health Services, a 30-hospital system based in Nashville, Tenn., and Nashville-based Vanderbilt University Medical Center around Thanksgiving.