John Buck Company Data Breach Exposes Social Security Numbers

The Chicago-based real estate firm, The John Buck Company, has disclosed a data breach affecting the personal information of individuals connected to its operations. According to a disclosure filed with the state of Massachusetts on Jan. 8, 2026, the incident compromised the sensitive data of at least 23 Massachusetts residents.

The breach exposed a range of personally identifiable information (PII) and protected health information (PHI), including names, Social Security numbers, driver’s license numbers, financial account numbers and health insurance information.

The breach notice indicates that the information was accessed due to a cybersecurity incident. While the exact method of intrusion and the identity of the responsible party have not been publicly disclosed, the exposure of Social Security numbers, financial account details and health insurance information suggests a high level of severity.

The John Buck Company’s response

In response to the incident, The John Buck Company has taken several steps to address the breach and support those affected. The company has enhanced its existing security measures to help prevent similar incidents in the future. As part of its mitigation efforts, TJBC is offering a complimentary, two-year membership of credit monitoring and identity theft protection services through Cyberscout, a TransUnion company. These services are available at no cost to affected individuals and enrolling will not impact credit scores.

Those affected are encouraged to remain vigilant by reviewing their financial account statements for any unauthorized activity. If suspicious charges or activity are detected, individuals should contact their financial institution immediately. The company has also established a dedicated help line at 833-961-6716, available Monday through Friday from 8 a.m. to 8 p.m. Central Time, excluding certain U.S. holidays. Detailed instructions on activating the complimentary services and additional recommended steps are included in the written notice sent to affected individuals.