Marquis Sues SonicWall Over 2025 Firewall Data Breach

Lawsuit Claims SonicWall Cloud Backup Flaw Led to Ransomware Attack Against Marquis Michael Novinson (MichaelNovinson) • February 25, 2026

Marquis Software Solutions sued SonicWall for allegedly misrepresenting the scope of the breach of its MySonicWall cloud backup service and causing financial and operational harm.

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The Plano, Texas-based marketing and compliance software provider said an attacker used exposed credentials and configuration data from the February 2025 SonicWall cloud breach to conduct a ransomware attack against Marquis in August 2025 and access sensitive client data. This occurred even though Marquis had multifactor authentication and advanced security controls enabled, the firm said.

"SonicWall had reason to know that using predictable device serial numbers created a foreseeable vulnerability that threat actors could - and did - easily exploit," Marquis wrote in a 35-page complaint. "SonicWall's reckless use of easy-to-predict, easy-to-brute-force serial numbers constitutes a marked failure to ...