Marquis Software Solutions reports ransomware attack exposing data of 672,075 banking customers

Marquis Software Solutions, a Texas-based technology vendor providing direct marketing, compliance software, and customer relationship management systems to of banks and credit unions across the United States, is reporting a ransomware attack that compromised the sensitive personal information of 6,876 financial institution customers. 

The company detected suspicious activity on its network on August 14, 2025. The company decided to pay the ransom demand but the stolen data was still exposed on the dark web. 

The breach affected member account information dating prior to 2020 that had been provided to Marquis by its financial institution clients. Community 1st Credit Union was notified by Marquis on October 27, 2025 that sensitive member information had been accessed by unauthorized parties. 

Exposed data includes:

• Full names of financial institution members
• Dates of birth
• Financial account numbers
• Social Security numbers
• Tax identification numbers

The company reported the attack to law enforcement authorities and began the process of working with affected financial institutions to identify impacted individuals and coordinate notification efforts. Community 1st Credit Union began sending written notices to affected members on November 17, 2025.

Marquis Software Solutions is providing all affected individuals with complimentary membership to Epiq Privacy Solutions ID, an identity protection service package that includes credit monitoring across all three major credit bureaus, dark web monitoring to detect if stolen information appears for sale on criminal marketplaces, credit protection services, change of address monitoring to detect fraudulent address changes, and identity restoration services to assist victims who experience identity theft as a result of the exposure.

Update - as of 3rd of December 2025, at least 400,000 people are so far confirmed affected by the data breach, according to legally required disclosures filed in multiple states. Marquis says that hackers exploited a vulnerability in its SonicWall firewall. The vulnerability was considered a zero-day, meaning the flaw was not known to SonicWall or its customers before it was exploited.

As of 4th of December 2025, the number of affected individuals is reported to be over 780,000 people.

As of 30th of December 2025, by compiling victim counts from multiple state breach registries, several law firms and cybersecurity researchers said the number of victims is likely between 788,000 and 1.35 million. Cybersecurity firm Comparitech also obtained a since-deleted breach notification letter from Iowa-based Community 1st Credit Union that claimed Marquis Software paid a ransom to the group behind the attack.

As of 17th of March 2026,  Marquis’s claims that the incident affected only their system and did not breach the customer’s systems,and that the number of affected individuals is 672,075. "Our customer reviewed the affected files on December 10, 2025, and afterwards worked to validate and identify individuals whose information may have been affected by the incident, and our customer worked as quickly as possible to obtain individuals’ most recent mailing address information."
In January, Marquis blamed the ransomware attack on a security breach disclosed by SonicWall on September 17, when the company warned customers to reset their MySonicWall account credentials.

The following banks have reported to be affected

1. 1st Northern California Credit Union
2. Abbott Laboratories Employees Credit Union
3. Advantage Federal Credit Union
4. Agriculture Federal Credit Union
5. Anderson Bancshares Inc
6. Alltrust Credit Union
7. Artisans' Bank
8. BayFirst National Bank
9. Bellwether Community Credit Union
10. Blaze Credit Union
11. C&N Bank
12. Cape Cod Five
13. Capital City Bank Group
14. Central Virginia Federal Credit Union
15. Clark County Credit Union
16. Community 1st Credit Union
17. Community Bancshares of Mississippi, Inc.
18. Cornerstone Community Financial Credit Union
19. CPM Federal Credit Union
20. CSE Federal Credit Union
21. CU Hawaii Federal Credit Union
22. d/b/a Community Bank
23. Discovery Federal Credit Union
24. Earthmover Credit Union
25. Educators Credit Union
26. Energy Capital Credit Union
27. Fidelity Cooperative Bank
28. First Community Credit Union
29. First Northern Bank of Dixon
30. Florida Credit Union
31. Fort Community Credit Union
32. Founders Federal Credit Union
33. Freedom of Maryland Federal Credit Union
34. Gateway First Bank
35. Generations Federal Credit Union
36. Gesa Credit Union
37. Glendale Federal Credit Union
38. Hope Federal Credit Union
39. IBERIABANK n/k/a First Horizon Bank
40. Industrial Federal Credit Union
41. Interior Federal
42. Interior Federal Credit Union
43. Interra Credit Union
44. Jonestown Bank & Trust Co.
45. Kemba Financial Credit Union
46. Liberty First Credit Union
47. Maine State Credit Union
48. Market USA FCU
49. MemberSource Credit Union
50. Michigan First Credit Union
51. MIT Federal Credit Union
52. New Orleans Firemen's Federal Credit Union
53. New Peoples Bank
54. Newburyport Five Cents Savings Bank
55. NIH Federal Credit Union
56. Pasadena Federal Credit Union
57. Pathways Financial Credit Union
58. Peake Federal Credit Union
59. Pelican Credit Union
60. Pentucket Bank
61. PFCU Credit Union
62. QNB Bank
63. Security Credit Union
64. Seneca Savings
65. ServU Credit Union
66. StonehamBank Cooperative
67. Suncoast Credit Union
68. Texoma Community Credit Union
69. Thomaston Savings Bank
70. Time Bank
71. TowneBank
72. Ulster Savings Bank
73. University Credit Union
74. Valley Strong Credit Union
75. VeraBank
76. Westerra Credit Union
77. Whitefish Credit Union
78. Zing Credit Union