Belden data breach: what happened and what to do

Belden, a networking and cable company, detected a targeted attack on its servers on November 12, 2020. HHS lists 9,840 people whose health information was involved. Exposed data included names, dates of birth, Social Security numbers, health insurance details and payroll bank details for some staff.

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Breach date: 12 Nov 2020
Affected: 9,840
Data exposed: Names, Dates of birth, Social security numbers, Health insurance information, Bank account numbers
Last updated: 27 Oct 2026

Reviewed by Anthon Wansland

Head of Product & Co-Founder

Serus is a privacy company with paid tools to find and remove your personal data. This page is free and based on official sources.

What happened

Belden Inc. said its IT team spotted unusual activity on company servers on the evening of November 12, 2020. Forensic experts determined that an outside party had targeted the company in a sophisticated attack. Belden announced the incident on November 24, 2020 and later updated its notice.

The scope grew over time. A supplemental notice in April 2021 said the affected servers also held personal information of some spouses, dependents and relatives of current and former employees, plus health-related information. A further supplemental notice followed on July 7, 2021.

Sources checked: businesswire.com, ocrportal.hhs.gov, consumer.ftc.gov

Last verified against the official page: 27 Oct 2026

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What was exposed

HHS's breach report describes a cybersecurity incident involving the protected health information of 9,840 people, including names, dates of birth, Social Security numbers and health insurance information. Belden's notices also list payroll bank account details for North American employees, home addresses and benefit details.

The company said it had no reason to believe specific health conditions or diagnoses were involved.

The response

Belden notified law enforcement, HHS, the media and the people involved, and gave complimentary credit monitoring. HHS says its Office for Civil Rights provided technical assistance.

Employees' relatives are easy to overlook here. If a former colleague's family details were on those servers, your own letter, not theirs, tells you what applies to you.

What to do if you were in it

1

Freeze your credit at all three bureaus

A credit freeze is free and stops anyone opening new credit in your name. Place one at Equifax, Experian and TransUnion; the FTC explains how. Do this for any family members who got a letter too.
2

Watch your bank account and ask about direct deposit

If your payroll bank details were involved, check statements closely and ask your bank whether to change your account number.
3

Use the free credit monitoring if you still can

Belden offered complimentary of free credit monitoring. The FTC recommends taking such offers. If you kept your letter, check whether the enrollment deadline has passed, and if it has, a credit freeze still protects you.
4

Expect phishing that mentions the breach

Messages about benefits, payroll or HR may be fake. Don't click links or call numbers in unexpected messages. Go to the company's own website instead, and report scams at ReportFraud.ftc.gov.
5

Report misuse and watch your reports

Check your credit reports at annualcreditreport.com. If someone uses your details, report it at IdentityTheft.gov to get a recovery plan.