Massachusetts medical firm Onsite Mammography discloses data breach impacting the personal information of 350,000 patients.
April 23, 2025 By Ionut Arghire
Massachusetts medical services provider Onsite Mammography is notifying over 350,000 people that their personal and health information was compromised in a data breach.
The incident was discovered in October 2024 and involved unauthorized access to an employee’s email account, the firm reveals in a notification letter mailed to the impacted individuals.
Some of the emails in the compromised account’s inbox, Onsite says, exposed both personally identifiable information (PII) and protected health information (PHI).
A review of the exposed information that was concluded in February 2025 determined that names, Social Security numbers, dates of birth, driver’s license numbers, credit card numbers, and medical information such as mental and physical health or condition, and received care information was compromised.