DuPage Medical Group is notifying 600,000 patients that their personal health information was exposed when the Downers Grove, Ill.-based medical group's computer network was hacked in July, The Chicago Sun-Times reported Aug. 30.
DuPage Medical Group, the largest independent physician group in Illinois, discovered the unauthorized activity on its computer network July 13. As a result, the group shut down access to its network and medical records for nearly a week.
The hacker had access to DuPage Medical Group's computer network July 12-13 and compromised the following information of the group's patients: names, birthdates, addresses, diagnosis codes, and Social Security numbers for a small number of people, among other details, according to DuPage Medical Group's online notice.
"To date, DMG has no evidence that any information has been subject to actual or attempted misuse as a result of this incident," the group wrote. "This event did not impact financial account numbers."
DuPage Medical Group is offering free credit monitoring and identity protection services to patients who may have been affected, and the group has implemented additional security measures as a result of the incident.
DuPage Medical Group is home to more than 750 primary care physicians across 100 locations. Annually, it handles 2 million patient visits, according to its website.