McLaren Health Care confirmed that its Aug. 6 IT disruption was the result of a ransomware attack.
The attack, according to an Aug. 16 update on the health system's website, is affecting McLaren's 13 hospitals, cancer centers, surgery centers and clinics.
"The disruption is expected to continue through the end of August, while cyber forensic investigations are ongoing," the update said. "The incident is contained, but access to certain McLaren systems remains limited."
The Grand Blanc, Mich.-based health system said it is in the process of identifying whether any protected health information was compromised as a result of the attack.
The update comes after the health system was hit with a ransomware attack last year. This incident, which exposed 2.2 million patients' information, was claimed by the ALPHV/BlackCat ransomware group. Multiple lawsuits against the health system were filed after the attack.