Marquis Software Solutions breach pinned on SonicWall hack

Texas-based financial services provider Marquis Software Solutions has attributed the August ransomware attack against its systems that impacted numerous banks and credit unions across the U.S. to a security breach at its firewall provider SonicWall, which came to light a month later, TechCrunch reports.

Third-party investigation into the incident was reported by Marquis to have revealed attackers' use of firewall data stolen from the SonicWall hack to facilitate further compromise of its systems.

"While the provider initially reported that fewer than 5% of customers were affected, it later clarified in October 2025 that firewall configuration data and credentials associated with all customers using the cloud backup service, including Marquis, had been accessed," said Marquis in a statement.

While Marquis is assessing potential recovery of incident response expenses and other actions against SonicWall, SonicWall has called on the fintech firm to further prove its assertions.

"We have no new evidence to establish a connection between the SonicWall security incident reported in September 2025 and ongoing global ransomware attacks on firewalls and other edge devices," said SonicWall spokesperson Bret Fitzgerald.