Where does the Mutual One Dec. case file come from?

Every entry is taken from the breach report Mutual One Dec. lodged with the Massachusetts Attorney General. Nothing here is estimated.

Why do the incident date and the report date differ?

Companies usually investigate before they report. The gap between the two dates shows how long that took.

What does the records-affected figure count?

It is the number the company gave the state. It can cover residents of that state only, so the national total may be higher.

Does this case file change over time?

Yes. When a company files an update or a new state publishes its copy of the report, the dates and counts here are refreshed.

Case file

Case File: Mutual One Dec. Data Breach

This file collects the dated facts on record for the Mutual One Dec. incident. The state report is dated January 5, 2026.

Timeline

January 5, 2026Report filed in MassachusettsDate the notice was lodged with the Massachusetts Attorney General.

Case facts

Filing state: Massachusetts
Date reported: January 5, 2026
Receiving office: Massachusetts Attorney General

Case notes

Mutual One Dec., a financial services and credit union based in Massachusetts, reported a data security incident to regulatory authorities on January 5, 2026. This notification confirms that an event affecting data security has occurred, and further investigation into its scope and impact is underway.

The official filing from Mutual One Dec. did not specify the exact nature of the security compromise or the method by which unauthorized access may have been gained. Details such as the precise date the breach began and the total number of individuals impacted were not provided in the public record.

Because the details remain under investigation, the specific categories of personal information involved in this incident are not known at this time. As a financial institution, Mutual One Dec. routinely handles a wide array of sensitive data as part of its operations, making any unauthorized access a significant concern for its members and clients.

Individuals who receive a direct notification letter from Mutual One Dec. should carefully review its contents. Such letters are intended to provide personalized details about the incident and confirm if their personal information was involved.

It is generally recommended for all individuals to remain vigilant following news of a data security incident. Regularly reviewing financial statements, credit reports, and account activity for any unfamiliar transactions or suspicious inquiries is a prudent measure. Consider placing a fraud alert or security freeze on your credit files with the major credit bureaus.

Additionally, be cautious of any unsolicited communications, such as emails, text messages, or phone calls, that claim to be from Mutual One Dec. and request personal or account details. Always verify the legitimacy of such requests by contacting the institution directly through official channels, rather than responding to suspicious contact.

Questions about this case file

Where does the Mutual One Dec. case file come from?: Every entry is taken from the breach report Mutual One Dec. lodged with the Massachusetts Attorney General. Nothing here is estimated.
Why do the incident date and the report date differ?: Companies usually investigate before they report. The gap between the two dates shows how long that took.
What does the records-affected figure count?: It is the number the company gave the state. It can cover residents of that state only, so the national total may be higher.
Does this case file change over time?: Yes. When a company files an update or a new state publishes its copy of the report, the dates and counts here are refreshed.

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Timeline

Case facts

Case notes

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