By Christopher Rowland, Globe Staff
The computer worm that struck systems around the nation over the last week breached security at Partners HealthCare Systems Inc. and infected 800 computers at four of its five acute-care hospitals, including Massachusetts General and Brigham and Women's in Boston.
Partners called the breach 'modest' and said it did not appear to have affected patient care or compromised medical records. The healthcare network has 55,000 computerized devices connected to its systems.
Responding to an alert of a vulnerability last week by Microsoft Corp., Partners computer experts had already installed preventive measures on the most sensitive records systems by the time the worm attacked Saturday night, said John Glaser, Partners chief information officer.
The systems affected were lower in priority, including computers used in research and in the human resources department, he said. The worm caused the computers to repeatedly reboot on their own, but did not destroy data.