Some patient data of Sea Mar Community Health Centers leaked after threat actors gained access to Sea Mar’s network and exfiltrated what they claimed was 3 TB of data. The compromised information includes name, address, Social Security number, date of birth, client identification number, medical / vision / dental / orthodontic diagnostic and treatment information, medical / vision / dental insurance information, claims information, and / or images associated with dental treatment. It included a few images of known young patients with dental problems. Each person carried a sign bearing their name, birthdate, and photo. A few insurance-related forms with patient data were also present. Sea Mar immediately took steps to secure its environment and commenced an investigation to determine.

Some patient data of Sea Mar Community Health Centers was leaked on Marketo, a marketplace for stolen and leaked data. The leaked data included the personal information of about 688,000 patients and some employees. Sea Mar investigated the incident and notified the impacted persons to be alerted.

The Maine Attorney General's Office was notified on November 5, 2021, about a data breach involving Sea Mar Community Health Centers that may have affected the personal information of six Maine residents. The breach involved unauthorized access to names and Social Security numbers, with an investigation revealing that additional data may have been copied between December 2020 and March 2021.