Almeida Law Group is investigating a data breach at MasTec, Inc. The breach occurred on August 9, 2025 and was discovered on April 23, 2026. If you were affected, contact Almeida Law Group.
About MasTec, Inc.
MasTec, Inc. is an infrastructure engineering and construction company headquartered in Coral Gables, Florida. It provides engineering, building, installation, maintenance, and upgrade services across communications, energy, utility, and other infrastructure sectors, primarily in the United States and Canada. The company is publicly traded on the NYSE under the ticker MTZ and employs more than 20,000 people. The specific types of personal information involved in this breach were not specified in available sources.
What Happened?
MasTec, Inc. was listed in a Maine Attorney General filing reporting an external system breach caused by hacking. According to the company’s notice, MasTec received reports of suspicious activity in a small portion of its computer network in early October 2025. An investigation determined that an unauthorized third party had accessed a limited section of the network for a few days in August 2025. MasTec engaged a data-review firm to analyze the affected files, received results in early February 2026, and then worked to obtain accurate contact information before notifying affected individuals. Consumer notification was sent on June 5, 2026, approximately ten months after the breach occurred. A total of 25,220 individuals were affected. MasTec is offering complimentary identity theft protection through CyEx Financial Shield, a financial account and personal information monitoring service.
The Clop (CL0P) ransomware group publicly claimed responsibility for a cyberattack on MasTec on October 28, 2025, with a posting on its leak site timestamped October 31, 2025. That timing aligns with MasTec’s disclosure that it received reports of suspicious activity in early October 2025. This is MasTec’s second significant cybersecurity incident in two years. In May 2023, MasTec was affected through a third-party vendor by the widespread MOVEit ransomware attack, which impacted approximately 22,000 current and former employees. A class action lawsuit was filed in November 2023 (Liptock v. MasTec, Inc., 2:23-cv-05753) alleging inadequate cybersecurity protections and a 153-day notification delay related to that prior incident. No class action lawsuit specifically connected to this August 2025 breach has been identified at this time.
Key Facts at a Glance
- Company or Organization: MasTec, Inc.
- Industry: Infrastructure Engineering and Construction
- Location: Coral Gables, Florida
- Incident type: External system breach (hacking)
- Date of breach: August 9, 2025
- Date breach discovered: April 23, 2026
- Date of consumer notification: June 5, 2026
- Total persons affected: 25,220
- Identity theft protection offered: Yes — CyEx Financial Shield (financial account and personal information monitoring)
- Prior breach: Yes — May 2023 MOVEit ransomware breach affecting approximately 22,000 employees; class action filed November 2023
- Litigation status: No lawsuit identified for this incident; prior class action (Liptock v. MasTec, Inc., 2:23-cv-05753) related to the separate 2023 breach
- Source: Maine AG Filing; Clop claim — DeXpose; Clop leak site posting — RedPacket Security; Prior MOVEit breach and litigation — ClassAction.org
What Should You Do?
If you received a notice from MasTec, enroll in the complimentary CyEx Financial Shield identity protection service by visiting https://app.financialshield.com/enrollment/activate/MasTec using your activation code, and contact CyEx directly at (844) 953-0840 if you need assistance or prefer to enroll by phone. Be sure to enroll before the deadline stated in your notice. Beyond that, review your financial account statements regularly and check your credit reports for any activity you do not recognize. You can request free credit reports at AnnualCreditReport.com or by calling (877) 322-8228. Consider placing a fraud alert or credit freeze with Equifax, Experian, and TransUnion to make it harder for anyone to open new accounts in your name. For additional guidance on protecting yourself from identity theft, visit IdentityTheft.gov.
Your Legal Rights
If your personal information was involved in this breach, you may have legal rights depending on the facts of the incident and the law in your state. Almeida Law Group represents consumers in data breach and privacy litigation and can help you evaluate whether you may have a claim. Contact us at (708) 529-5418 or through our contact page for a free case evaluation.
