Marquis reports data breach affecting over 672,000 people in a ransomware attack

Marquis, a technology firm relied upon by hundreds of banks to analyse and visualise customer data, has disclosed that the personal and sensitive financial information of hundreds of thousands of individuals was compromised in a ransomware attack last year.

The Plano, Texas-based fintech company is informing at least 672,075 people that hackers accessed their data during a cyberattack that occurred in August 2025, according to a filing with the Maine attorney general’s office.

A separate data breach notification submitted in Texas indicates that more than half of the affected individuals are residents of the state.

This disclosure provides the most comprehensive account to date of the scale of the breach, which had not been publicly reported before this announcement.

According to the company, the breach exposed customers’ personal details, including names, dates of birth, and mailing addresses. In addition, sensitive financial data was compromised, including bank account details, debit card numbers, and credit card information. Marquis also confirmed that Social Security numbers were among the data accessed by the attackers.

In February, Marquis filed a lawsuit against its firewall provider, SonicWall, alleging that security shortcomings on the provider’s part enabled the breach. The company claims that these vulnerabilities allowed hackers to obtain critical information about its firewall systems, which was then used to infiltrate Marquis’ network, exfiltrate data, and deploy ransomware.

In the legal complaint, Marquis asserted that SonicWall’s systems contained a flaw that allowed attackers to access backup firewall configuration files, including those belonging to Marquis itself.