In early March 2025, National Presto Industries, a Wisconsin-based manufacturer known for its home appliances and defense products, experienced a significant cyberattack that disrupted its operations. The company disclosed the incident in a regulatory filing with the Securities and Exchange Commission (SEC), stating that the attack led to a system outage affecting shipping, receiving, manufacturing processes, and various back-office functions. To address the situation, National Presto activated its incident response team, comprising internal personnel and external cybersecurity experts, and implemented temporary measures to maintain critical functions while systems were being restored. ([sec.gov](https://www.sec.gov/Archives/edgar/data/80172/000143774925006475/npk20250306_8k.htm?utm_source=openai))
On April 1, 2025, the InterLock ransomware group claimed responsibility for the attack, adding National Presto Industries’ subsidiary, National Defense Corporation, to its Tor-based leak site. The group alleged that it had stolen approximately 450,000 folders containing nearly 3 million files from the company. InterLock also claimed to have encrypted the systems of at least three National Presto Industries entities, including AMTEC, a subsidiary that manufactures ammunition and explosives.
InterLock reported that it attempted to extort the company, but negotiations were unsuccessful. According to the ransomware group, National Defense Corporation did not consider the incident significant, stating that the stolen information would be of no value to others and that the financial impact would be minimal. The company also allegedly informed InterLock that it had restored its systems and resumed normal operations.
National Presto Industries has not publicly commented on InterLock’s claims. The company continues to work with law enforcement and regulatory bodies to investigate the incident and assess its full impact. The potential ramifications on the company’s financial condition and operational performance remain under evaluation. ([sec.gov](https://www.sec.gov/Archives/edgar/data/80172/000143774925006475/npk20250306_8k.htm?utm_source=openai))
