Rolls of steel at the Nucor Corp. plant in Ghent, Ky. (Timothy D. Easley/Associated Press)
Nucor Corp., the biggest steel manufacturer in North America, shut down production at some of its facilities after detecting an unauthorized intrusion into its computer systems.
The company took potentially affected systems offline and implemented other containment measures, Nucor said in a disclosure filed with the Securities and Exchange Commission on May 14.
Nucor said it is investigating the incident with external cybersecurity experts and has notified federal law enforcement. It is currently in the process of restarting the affected operations, according to the statement.
A company spokesperson did not immediately respond to a request for comment.
Hackers have targeted the manufacturing industry more than any other for four years in a row, according to IBM’s X-Force 2025 threat intelligence report. The sector has experienced significant disruption from incidents involving data theft and extortion, with attackers exploiting outdated legacy technology that is prevalent in the industry, the report found.
President Donald Trump has championed U.S. steelmakers, among the chief focuses of his vows to revive American manufacturing. Nucor and its domestic peers celebrated the tariffs Trump imposed on steel imports as they come off their worst year since his first term in office amid lackluster construction demand, inflation and high borrowing costs.
Nucor, headquartered in Charlotte, N.C., operates dozens of facilities across the U.S. The company’s net sales in the first quarter were $7.83 billion.
