Marquis Software Solutions Sues SonicWall Over Ransomware Attack

Marquis Software Solutions has taken legal action against cybersecurity company SonicWall, alleging gross negligence and misrepresentation that led to a ransomware attack affecting 74 U.S. banks.

Following a breach on August 14, 2025, hackers infiltrated Marquis’ network through a compromised SonicWall firewall, resulting in a ransomware attack that disrupted operations and exposed sensitive personal information.

The stolen data included names, addresses, phone numbers, Social Security numbers, Taxpayer Identification Numbers, and financial account details.

Marquis Software Solutions, known for providing data analytics, CRM tools, compliance reporting, and digital marketing services, serves a wide range of clients, including over 700 banks, credit unions, and mortgage lenders.

In January 2026, Marquis accused SonicWall of security failures, revealing that the attackers exploited a vulnerability in SonicWall’s cloud backup infrastructure, rather than an unpatched firewall flaw as initially thought.

The breach stemmed from a security gap introduced by SonicWall in its MySonicWall cloud backup service through an API code change in February 2025, allowing unauthorized access to encrypted credentials and configuration data.

Despite initially downplaying the impact, SonicWall later confirmed that all clients were affected by the breach, which was orchestrated by state-sponsored hackers according to an investigation by Mandiant.

Marquis highlights that its up-to-date firewall with multi-factor authentication (MFA) and additional security measures were compromised due to information obtained from the SonicWall cloud backup breach.

Allegedly, SonicWall failed to provide crucial details regarding the MFA bypass when approached by Marquis, leading to financial losses, damage to reputation, and ongoing legal battles for Marquis.

Marquis is currently facing numerous consumer class action lawsuits following the ransomware attack and is seeking monetary damages, indemnification, contribution for related judgments, attorneys’ fees, and equitable relief.

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