Texas-based bank-marketing fintech Marquis Software Solutions disclosed one of 2025's largest financial-sector data breaches: ransomware operators stole personal and financial data belonging to 672,075 individuals and disrupted operations at 74 U.S. banks and credit unions.
What Marquis confirmed
Marquis provides CRM, compliance, and analytics services to more than 700 financial institutions. In notification letters filed with state attorneys general in March 2026, the company said attackers entered its network on August 14, 2025 after compromising a SonicWall firewall, then exfiltrated names, dates of birth, addresses, phone numbers, Social Security numbers, taxpayer identification numbers, and financial account information (without security or access codes).
SonicWall blame and lawsuits
Marquis attributed the breach to SonicWall's September 2025 MySonicWall/cloud-backup incident and filed suit accusing SonicWall of gross negligence. The fintech said it was defending more than 36 consumer class actions stemming from the attack.
What to do if your bank used Marquis
- Watch for breach letters from your bank or credit union—not leak-site downloads.
- Freeze credit and enable fraud alerts if SSNs were involved.
- Hang up on unsolicited calls asking to "verify" account PINs or routing numbers.
Canonical record: Marquis 2025 on BreachHistory.
Sources: BleepingComputer