National Defense Corp Ransomware Breach: How Centralized File Shares Enabled 4.2TB Data Theft

In March 2025, the Interlock ransomware group exfiltrated 4.2TB of sensitive data from National Defense Corp (NDC) before encrypting its systems. The breach was enabled by exposed file shares, persistent administrative credentials, and centralized storage architecture. This incident demonstrates how modern ransomware campaigns scale through internal reachability rather than technical sophistication, highlighting the importance of architectural risk reduction.

Why This Ransomware Attack Matters for Defense, Telecom, and Critical Infrastructure Leaders

What makes the NDC breach significant is the attackers’ ability to remove terabytes of sensitive data once inside the network.

After obtaining valid access, Interlock encountered an environment where engineering and production data were concentrated behind discoverable services. This allowed weeks of undetected exfiltration before encryption and disclosure.

For defense contractors and regulated enterprises, this incident reinforces a core lesson: breach impact is shaped by architecture. When systems are centralized and broadly reachable, one compromised credential can translate into enterprise-wide exposure.

What Happened: Timeline of the National Defense Corp Ransomware Attack (March 2025)

In March 2025, National Defense Corp, a U.S.-based ammunition manufacturer and subsidiary of National Presto Industries, suffered a ransomware attack attributed to the Interlock group.

According to DataBreaches and SEC disclosures, attackers exfiltrated approximately 4.2TB of data before encrypting systems and disrupting manufacturing operations. The company declined to pay a ransom.

Independent monitoring confirmed that stolen data appeared on Interlock’s leak site, including engineering, procurement, and customer-related files referencing defense-sector partners.

How the Attack Worked: Credential Abuse, SMB File Shares, and Data Exfiltration

The incident followed a common ransomware progression enabled by credential abuse and centralized infrastructure.

Data theft preceded encryption, indicating that information extraction was the primary objective.

Root Cause Analysis: Why Centralized File Servers Created Systemic Exposure

The breach scale was enabled by structural design choices.

These conditions optimized internal access but limited containment.

Key Risk Signals: Warning Signs of High Ransomware Exposure

Organizations face elevated risk when:

• Sensitive IP is centrally stored
• Administrative credentials are long-lived
• Internal services are easily discoverable
• Segmentation between users and production systems is weak
• Data movement is loosely governed

When multiple signals apply, breach impact is likely to be systemic.

Architectural Alternative: How Entropya D3 Reduces Ransomware and Data Theft Risk

One way to reduce ransomware impact is to remove centralized, always-on storage services.

Entropya’s Digital Dead Drop (D3) architecture distributes encrypted data fragments across multiple nodes and synchronizes them through ephemeral communication paths. Complete datasets are not exposed through fixed internal endpoints.

Each D3 node is deployed behind a Virtual Dissimulated Encrypted Server (VDES). This combined architecture hides the real server address, masks the underlying network topology, and prevents attackers from learning where data is stored. Instead of exposing a predictable storage device, each server is accessed only through an obfuscated VDES endpoint that changes over time. Adversaries cannot map nodes, cannot locate the true servers, and cannot determine which fragments reside where.

Entropya’s Data Vault stores these encrypted fragments inside a hardened, tamper-resistant environment. Each fragment is wrapped in post-quantum cryptography and isolated from identifiable metadata. Data retrieval requires authenticated, session-based access, ensuring that even with compromised credentials, attackers can’t observe, correlate, or aggregate stored data. 

This architecture limits attackers’ ability to map, aggregate, and extract large volumes of data, even if initial access occurs.

FAQs: Entropya D3 and Secure Data Architecture

How does D3 reduce ransomware risk?

• By eliminating centralized file shares and using distributed encrypted fragments, D3 limits what attackers can access after intrusion.

What does D3 provide beyond traditional security tools?

• This is an architectural mitigation, not just a monitoring or response tool. This gives organizations an architectural way to limit the amount of data an attacker can reach. Instead of relying on alerts or behavioral detection, the D3 and VDES deployment reduces what is discoverable and prevents attackers from locating or aggregating meaningful datasets.

How does VDES contribute to protection?

• The VDES ensures the real servers cannot be identified. It removes fixed server addresses, hides internal network location, and presents only temporary service endpoints. The environment is camouflaged, which blocks mapping and prevents targeting of the actual storage nodes.

Can these solutions be deployed on legacy infrastructure? 

• Yes. Entropya’s solutions are infrastructure agnostic and require little to no configuration for a plug-and-play deployment.

Sources

• Data Breaches - National defense corporation victim of ransomware attack
• Secure Frame - Recent Cyber Attacks 2025
• Security Week - Ransomware group takes credit for National Presto Industries attack
• Radar offseq - How Interlock Ransomware Affects the Defense Industrial Base Supply Chain
• Hunter Strategy - The rise of Interlock ransomware group