Gurnee-based Illinois Gastroenterology Group was hit with a network breach in October, the company said April 22.
The group said it discovered unusual activity in its computer network Oct. 22 and launched an investigation with a third-party cybersecurity group to determine the scope of it. On Nov. 18, it found that an unauthorized party gained access to information in the system.
Affected patients may have had their information compromised, including name, Social Security number, address, date of birth, driver's license number or state identification card number and financial account information.
To date, Illinois Gastroenterology Group said it has not received any reports of fraudulent use of the potentially affected information.