Steel Mills

Nucor reports IT systems breach

Written by Stephanie Ritenbaugh

May 14, 2025

Nucor Corp. reported a cybersecurity breach of its IT systems.

In a filing with the US Securities and Exchange Commission, Nucor said it identified an incident “involving unauthorized third-party access to certain information technology systems used by the company.”

The Charlotte, N.C.-based steelmaker said it took the affected systems offline and implemented other containment, remediation, or recovery measures.

“The company is actively investigating the incident with the assistance of leading external cybersecurity experts and has notified federal law enforcement authorities,” Nucor said in the May 13 filing.

The steelmaker said it temporarily and proactively halted some production operations at various locations.

A spokeswoman declined to specify which locations were affected.

“Despite this interruption, we are taking care of our customers and are in the process of restarting the affected operations,” the spokeswoman said.

Nucor is the largest steelmaker in North America with 26 US-based mills and more capacity coming online.

Stephanie Ritenbaugh

Stephanie Ritenbaugh is a reporter for Steel Market Update. She is an experienced business journalist, holding a variety of positions for trade publications and newspapers, including covering shale development for Gas Business Briefing/Platts and for the Pittsburgh Post-Gazette. She can be reached at stephanie.ritenbaugh@crugroup.com or +1 724-759-7868

Read more from Stephanie Ritenbaugh

Latest in Steel Mills