Marquis Software Solutions Suffers Ransomware Attack, Exposing Customer Data of Numerous Financial Institutions
Financial software provider Marquis Software Solutions experienced a ransomware attack on August 14, 2025, through a vulnerability in its SonicWall firewall. This breach led to the exfiltration of personal and financial information belonging to customers of over 74 US banks and credit unions. The stolen data included names, addresses, phone numbers, Social Security numbers, Taxpayer Identification Numbers, financial account information (without security or access codes), and dates of birth. The incident impacted an estimated 400,000 to over 800,000 individuals. Marquis began sending notifications to affected parties in early December 2025.
Signal context
First seen: Aug 14, 2025
Last updated: Jun 26, 2026
Status: Public signal
Key points
- Ransomware attack occurred on August 14, 2025.
- Initial access gained through a SonicWall firewall vulnerability.
- Stolen data includes names, addresses, phone numbers, Social Security numbers, Taxpayer Identification Numbers, financial account information (without access codes), and dates of birth.
Signal analysis
BetaThis analysis groups the signal by industry, likely incident action and impacted security area. It helps compare this signal with other published signals without treating the labels as final determinations.
Sector: Information
Likely country: 🇺🇸 US
inferred from signal text
Watch ransomware, endpoint compromise and business interruption exposure.
- Source type: outside the affected organization
Impact area: Confidentiality, Availability
Likely asset: User or customer data
- 26 signals in the same sector
- 100 signals with the same likely impact area
- 1 signal linked to this organization/domain
External sources
Marquis Software Data Breach - The Lyon Firmhttps://www.lyonfirm.com/marquis-software-data-breach/Public source from lyonfirm.com.
Marquis data breach impacts over 74 US banks, credit unions - Bleeping Computerhttps://www.bleepingcomputer.com/news/security/marquis-data-breach-impacts-over-74-us-banks-credit-unions/Public source from bleepingcomputer.com.
Marquis data breach impacted more than 780,000 individuals - Security Affairshttps://securityaffairs.com/155359/data-breach/marquis-data-breach.htmlPublic source from securityaffairs.com.
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