MountainOne Data Breach Investigation

Turke & Strauss LLP, a leading data breach law firm, is investigating MountainOne Bank regarding its recent data breach. The MountainOne data breach involved sensitive personal identifiable information belonging to an undetermined number of individuals.


MountainOne is a mutual holding company that specializes in providing banking, insurance, and financial service products. Founded in 1848, MountainOne offers personal and business loans and services, including credit card approval, a variety of bank account types, lending services, insurance options, and more. Furthermore, MountainOne provides a full suite of electronic banking resources, enabling ease of access and simplicity in an otherwise complicated banking and investing environment. Headquartered in North Adams, Massachusetts, MountainOne conducts business throughout the Berkshires and Boston’s South Shore.


Recently, MountainOne discovered that it had experienced a data breach in which the sensitive personal identifiable information in its systems may have been accessed. Through its investigation, MountainOne determined that an unauthorized actor may have accessed this sensitive information. On December 9, 2022, MountainOne began contacting individuals whose information may have been impacted. The type of information exposed includes:

  • Name
  • Social Security number
  • Driver’s license number
  • Financial information (e.g., account number, credit or debit card number)

If you received a breach notification letter from MountainOne:

We would like to speak with you about your rights and potential legal remedies in response to this data breach. Please fill out the form, below, or contact us at (608) 237-1775 or

If you were impacted by the MountainOne data breach, you may consider taking the following steps to protect your personal information.

  1. Carefully review the breach notice and retain a copy;
  2. Enroll in the free credit monitoring service provided by MoutnainOne Bank;
  3. Change passwords and security questions for online accounts;
  4. Regularly review account statements for signs of fraud or unauthorized activity;
  5. Monitor credit reports for signs of identity theft; and
  6. Contact a credit bureau(s) to request a temporary fraud alert.

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