CoMark Data Breach Exposes Sensitive Personal Information in 2025 CoMark, a data management firm, reported a significant data breach to the Maine Attorney General after detecting unauthorized network access on or around March 18, 2025. The company launched an investigation, confirming that an unauthorized third party accessed and potentially acquired sensitive personal identifiable information (PII) stored in its systems. Following a thorough review, CoMark determined on December 17, 2025, that exposed data included names and Social Security numbers, though the exact details varied by individual. In response, the company began mailing breach notification letters to affected individuals, outlining the compromised information and offering complimentary credit monitoring services. The breach notice filed with the Maine Attorney General provides further details on the incident.