More than 672,000 people had their personal and financial data stolen in the ransomware attack, Marquez says

Marquis, a technology company used by hundreds of banks to analyze and visualize their customers’ data, says hundreds of thousands of people had their personal and sensitive financial information stolen in a ransomware attack last year.

The Plano, Texas-based fintech company notified at least 672,075 people that hackers stole their information during the August 2025 cyberattack, according to a list from the Maine Attorney General’s Office.

More than half of those affected live in Texas, according to a separate data breach notification filed in the state.

This revelation is the most complete picture yet of the number of people affected by the hack, which had not been previously reported.

The hack allowed hackers to steal bank customers’ names, dates of birth and mailing addresses. Hackers also stole customers’ financial information, such as bank accounts and debit and credit card numbers. The hackers also took customers’ Social Security numbers, Marquez said.

The fintech company filed a lawsuit against its firewall provider, SonicWall, in February, accusing the company of security failures that allowed hackers to steal critical information about its firewalls, which the hackers then used to breach the Marquis network, steal data, and spread ransomware.

Marquis said in its lawsuit that SonicWall created a vulnerability that allowed hackers to steal its customers’ firewall configuration backup files, including Marquis’s own files.

Marquez did not immediately comment when contacted by TechCrunch.