Diablo Valley Oncology and Hematology Medical Group - Press Release Listed by Monti Ransomware Group

On January 4, 2024, the monti Ransomware Group listed Diablo Valley Oncology and Hematology Medical Group on its leak site, claiming that internal files had been exfiltrated during a ransomware attack on the California-based cancer care provider. Patients and their families whose sensitive medical and personal information may have been taken are now at elevated risk of identity theft and targeted fraud.

Reported Details from the Listing

The monti leak-site entry states that Diablo Valley Oncology and Hematology Medical Group suffered a ransomware incident in which attackers successfully exfiltrated internal files. The disclosure does not quantify the number of affected records, list specific data types beyond “internal files,” or reveal the ransom amount demanded. It simply presents the victim organization alongside a sample of allegedly stolen material and a countdown timer, consistent with the group’s standard extortion format. The listing does not detail which systems were initially compromised or how the attackers gained access.

January 4, 2024 marks the first public confirmation of the breach via the monti leak site, accessible through the ransomware.live mirror.

Why This Matters for You and Your Family

If you or a family member received care at Diablo Valley Oncology and Hematology Medical Group, your medical history, treatment records, insurance details, and personally identifiable information may now sit on a criminal server. Cancer patients and their households often share Social Security numbers, dates of birth, addresses, and payment information during intake and billing. Once exposed, these details enable precise identity theft, insurance fraud, and phishing campaigns tailored to health vulnerabilities. Even when exact record counts remain unknown, the targeting of a medical practice signals high-value data that commands premium prices on underground markets.