MasTec Data Breach Class Action Lawsuit Investigation
Abington Cole + Ellery is investigating potential legal claims related to the MasTec data breach, which reportedly affected about 25,000 individuals and may have exposed personal information.
MasTec
Data Potentially Breached:
NAME / PERSONAL INFORMATION
Number Affected:
APPROXIMATELY 25,000
Published June 6, 2026 | Last updated June 6, 2026
Reviewed by Cornelius P. Dukelow -- licensed lawyer and registered patent attorney.
What happened in the MasTec data breach?
According to MasTec’s data breach notice, the incident began when the company received reports of suspicious activity in a small portion of its computer network in early October 2025. MasTec says it brought in third-party cybersecurity experts to investigate and remediate the activity, and later that month determined that an unauthorized third party had accessed a limited part of the network for several days in August 2025. The notice does not describe the exact intrusion method, such as phishing, malware, stolen credentials, or exploitation of a vulnerability. After identifying affected files, MasTec hired a data-review firm to analyze their contents, received the review results in early February 2026, and then worked to confirm contact information for impacted individuals before sending notices. MasTec says it also further secured its systems and notified law enforcement.
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How did the breach happen?
At the time of this posting, the details about how the MasTec data breach happened have not been released publicly, but several outlets are reporting that MasTec was the victim of a ransomware attack.
When did the breach occur?
The MasTec data breach reportedly took place on or around August of 2025.
How many people were affected by the breach?
Approximately 25,000 individuals were affected by the MasTec data breach.
What information was exposed in the breach?
- Breached data reportedly may include, but is not necessarily limited to:
- name
- personal information
Has MasTec offered free credit monitoring and/or identity theft protection services?
Yes. MasTec is offering affected individuals complimentary identity-theft-protection services through Financial Shield.
MasTec data breach timeline:
| Date | Event |
|---|---|
| August of 2025 | Unauthorized activity began. |
| October of 2025 | MasTec discovered the incident. |
| August of 2025 | Unauthorized activity ended. |
| February of 2026 | Data breach investigation concluded. |
| June of 2026 | MasTec began notifying affected individuals. |
Who is MasTec?
MasTec, Inc. is a North American infrastructure engineering and construction company based in Coral Gables, Florida. The company designs, builds, installs, maintains, and upgrades infrastructure for communications, energy, utilities, and related markets. Its main business areas include wireless and fiber communications networks, electric power delivery, pipeline infrastructure, renewable energy projects, heavy civil work, and industrial infrastructure. Publicly traded on the New York Stock Exchange under the symbol MTZ, MasTec reported about $14.3 billion in revenue for 2025, reflecting its role as a large contractor serving utilities, energy companies, telecommunications providers, and other infrastructure customers.
What should affected individuals do?
MasTec is advising victims to monitor account statements and credit reports, consider fraud alerts or credit freezes, and report suspicious activity.
MasTec Data Breach Notice
The notice describes the MasTec data breach, including the type of information that may have been involved and the steps offered to affected individuals.
Open the MasTec Data Breach Notice in a new tab.
Additional information about the breach:
MasTec Data Breach Notice (Attorney General of Maine)
Board Cybersecurity: MASTEC INC Cybersecurity Incident
DeXpose: Clop Ransomware Targets Engineering Giant MasTec Inc.
For more information about steps you can take to possibly reduce the chances harm arising from a data breach, please review the following article: What are some steps you can take if you've been the victim of a data breach?
This website is not associated with nor authorized by MasTec or any affiliated companies. If you have received any other data breach notifications, you may to review Abington Cole + Ellery's current list of data breach investigations.