Marquis data breach impacted more than 780,000 individuals

Marquis Software detected a ransomware attack on August 14, 2025, resulting from unauthorized access through a SonicWall firewall; attackers may have stolen files containing names, addresses, Social Security numbers, dates of birth, taxpayer IDs, and payment card data, impacting over 780,000 people. Marquis engaged security specialists, notified law enforcement, began notifying affected individuals and state attorneys general, and is offering credit monitoring while reporting no current evidence of misuse.