Marquis data breach impacts over 74 US banks, credit unions

According to Bleeping Computer, Marquis Software Solutions warned that a data breach affected dozens of banks and credit unions across the US, with the company stating it suffered a ransomware attack on 14 August 2025 after its network was breached through a SonicWall firewall. The notification filed with Maine’s attorney general says that the breach involved “certain files from its systems” containing personal information from some business customers.

Maine’s notice details 42,784 Maine residents affected, of whom 38,334 were customers at Maine State Credit Union; this does not include 51,000 Norway Savings Bank customers affected by the breach, 44,259 of whom are Maine residents. The article notes that the total number affected has not been disclosed, but reports to Maine, Iowa, South Carolina, Massachusetts, Washington State and Texas indicate a subtotal of approximately 721,000 affected consumers so far.

Marquis Software Solutions provides data analytics, CRM tools, compliance reporting and digital marketing services to over 700 banks, credit unions and mortgage lenders.