Largest US steel manufacturer puts production on the backburner after cyber attack
The company confirmed the breach to the SEC

- Nucor confirmed suffering a cyberattack
- It was forced to shut down parts of its operations to contain the incident
- No threat actors claimed responsibility yet
Nucor, one of the biggest steel manufacturers in the United States, was forced to shut down parts of its operations to address an ongoing cyberattack. The company confirmed the news in a new 8-K form filed with the US Securities and Exchange Commission (SEC).
In the filing, Nucor said it recently observed an “unauthorized third party” accessing “certain information technology systems.” When it spotted the intrusion, it activated its incident response plan, brought in a third-party cybersecurity company to assist, and notified relevant law enforcement agencies.
However, it also took “potentially affected systems offline” to implement “other containment, remediation, or recovery measures”.
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Was it ransomware?
Nucor told the SEC that it “temporarily and proactively” stopped certain production operations at various locations “in an abundance of caution”. It is now restarting those operations, it added.
Usually, when a company shuts down its operations to contain a cyberattack, it usually ends up being a ransomware attack. While the company did not explicitly say so, the fact that it halted operations could suggest this is the case.
Furthermore, The Register tried reaching out to the company’s facilities around the US, but found many phone numbers “either shut down or unobtainable.” Sometimes, a ransomware attack also results in inaccessible phone lines.
The importance Nucor plays in supporting the US critical infrastructure would also make it a prime target for ransomware attackers. No threat actors have claimed responsibility just yet, and we don’t know if any sensitive data was taken in the breach.
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Nucor is headquartered in Charlotte, North Carolina, and is widely considered as the largest US steel producer, and one of the top recyclers. It operates more than 300 facilities across the US, Canada, and Mexico, and manufactures a wide range of steel products. Last year, it reported annual net sales of $30.73 billion.
Via The Register
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Sead is a seasoned freelance journalist based in Sarajevo, Bosnia and Herzegovina. He writes about IT (cloud, IoT, 5G, VPN) and cybersecurity (ransomware, data breaches, laws and regulations). In his career, spanning more than a decade, he’s written for numerous media outlets, including Al Jazeera Balkans. He’s also held several modules on content writing for Represent Communications.
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