Cybercriminals stole data about patients in a ransomware attack that forced Ascension to revert to using paperwork last month, the hospital system said.
Data was stolen from seven of its nearly 25,000 servers across the country, Ascension said in a statement posted Wednesday.
Some stolen files contained health data and personally identifiable information.
Ascension said there is no evidence that data was stolen from its electronic health records, which contain full patient records.
The attacker infiltrated the hospital network after an employee accidentally downloaded a malicious file.
