Kiewit Data Breach Exposes Social Security Numbers

Kiewit Corp., one of North America's largest construction and engineering companies, disclosed a data breach that may have exposed the personal information of current and former employees and independent contractors.

The company provides construction and engineering services in markets including transportation, power, water, mining, oil and gas and building construction, and operates through a network of subsidiaries in the United States, Canada and Mexico.

Kiewit detected unauthorized access to an employee's Microsoft 365 account.

Following detection, Kiewit conducted a comprehensive review to determine which individuals' personal information may have been involved in the incident. The review was completed on July 24, 2026.

The types of personal information that may have been exposed included names, addresses, dates of birth, Social Security numbers, driver's license numbers or other government-issued identifiers and health information received in connection with employment.

The breach was disclosed to the Massachusetts Office of Consumer Affairs and Business Regulation on Aug. 26, 2026. The company mailed notification letter to affected individuals on Aug. 21, 2026.

Kiewit's response to the breach

Kiewit is offering affected individuals complimentary identity theft protection and credit monitoring services through IDX for a period of 12 to 24 months. The monitoring services must be activated in order to take effect, according to the notification.

Affected individuals can enroll by visiting the IDX enrollment page or by calling 1-833-788-9712. The deadline to activate these services is Nov. 21, 2026.

Kiewit has established a dedicated call center to answer questions from affected individuals about the breach and the resources available to them. The call center can be reached at 1-833-788-9712 and is available Monday through Friday from 9 a.m. to 9 p.m. Eastern time, excluding holidays.