Stockton Cardiology Medical Group Hit by Major Data Breach, Exposing Patient and Financial Data Stockton Cardiology Medical Group, a leading cardiology practice serving California’s San Joaquin Valley, suffered a significant data breach after detecting suspicious emails on December 15, 2025. Though the emails were quickly deleted, an investigation revealed that unauthorized access had occurred, with files potentially removed from the organization’s systems. By January 17, 2026, some of the compromised data was publicly disclosed. On February 17, 2026, the hacking group GENESIS claimed responsibility, announcing on the dark web that it had exfiltrated 645GB of data, including healthcare records, personal and financial information, and internal operational files. The breach was officially reported to the California Attorney General on March 20, 2026. Exposed data includes: - Patient names - Mailing and email addresses - Billing records - Limited medical information tied to services provided The law firm Shamis & Gentile P.A. is investigating the incident on behalf of affected individuals, who may be eligible for compensation due to potential damages such as identity monitoring costs, emotional distress, or financial losses. The breach underscores the growing threat to healthcare providers and the sensitive data they manage.