Marquis, a technology company that supports numerous banks with customer data analysis and visualization, reports that a ransomware attack last year resulted in the theft of personal and sensitive financial information of hundreds of thousands of individuals.
The fintech firm based in Plano, Texas, is informing at least 672,075 individuals about the breach of their data during the cyberattack in August 2025, as detailed in a record with the Maine attorney general’s office.
More than half of those affected reside in Texas, as indicated by another data breach notice filed in the state.
This disclosure provides the most comprehensive view of the impact of the breach, which had not been reported earlier.
The breach led to the theft of banking customers’ names, birth dates, and postal addresses, along with financial details such as bank accounts, debit, and credit card numbers. Marquis revealed that Social Security numbers were also compromised.
The fintech company filed a lawsuit against its firewall provider, SonicWall, in February, alleging that the company’s security lapses enabled hackers to access critical firewall information, ultimately compromising Marquis’ network, leading to data theft and ransomware deployment.
The lawsuit claims that SonicWall’s security flaw allowed hackers to steal firewall configuration backup files, including those owned by Marquis.
Marquis did not provide an immediate response when contacted by TechCrunch.