National Defense Corporation reports ransomware attack, data breach
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National Defense Corporation (NDC), a fully owned subsidiary of National Presto Industries, Inc. headquartered in Janesville, Wisconsin, is reporting a significant cybersecurity incident. The company, through its AMTEC division, is a major manufacturer of lethal and non-lethal ammunition, explosives, and cartridges for military and law enforcement use.
The parent corporation, National Presto Industries, reports that experienced a system outage caused by a cybersecurity incident on March 1, 2025. A threat actor group known as InterLock has claimed responsibility for the attack on their darkweb leak site. SInterLock claims to have:
- Exfiltrated 4,200 GB of data
- Obtained 2,900,205 files and 449,989 folders
- Provided screenshots as proof of their claims
- Fully encrypted "all AMTEC, Tech Ord, and PRESTO systems" in the attack
According to the SEC filing, the incident:
- Temporarily impacted the company's operations
- Affected shipping and receiving capabilities
- Disrupted some manufacturing processes
- Impacted various back office functions
The types of compromised data and number of affected individuals have not been disclosed.
The company has implemented temporary measures to maintain critical functions while systems are being restored. NDC reportedly engaged in negotiations with InterLock, which the threat actors characterized as unsuccessful.
