Nucor Steel Manufacturer Halts Production After Cyberattack

Nucor Corporation, one of North America’s largest steel producers, has temporarily halted production at multiple facilities following a cybersecurity breach that compromised critical operational systems.

The incident, disclosed in a May 15, 2025, SEC filing, marks one of the most significant cyberattacks on heavy industry infrastructure in recent years.

While the Charlotte-based company has begun restarting affected operations, the ongoing investigation underscores vulnerabilities in industrial supply chains and raises concerns about long-term operational and financial repercussions.

Nucor detected unauthorized access to its information technology systems in early May 2025, prompting an immediate response to contain the threat.

Though the company has not disclosed specifics about the attack vector or perpetrators, the breach disrupted systems integral to manufacturing processes, forcing a precautionary shutdown of production lines at several U.S. plants.

The decision to halt operations reflects the escalating risks of cyber threats to industrial control systems, which increasingly rely ...