Interlock Ransomware is a sophisticated ransomware threat actor that has recently targeted entities within the defense industrial base (DIB), specifically focusing on National Defense Corporation and its subsidiaries such as AMTEC, a manufacturer of ammunition and explosives. The attack methodology involves encrypting critical operational data and simultaneously exfiltrating sensitive information related to defense contractors, including contract details, logistics, and distribution networks. This double extortion tactic not only disrupts the availability of essential systems but also threatens confidentiality by threatening to leak intellectual property and sensitive supply chain data. The ransomware campaign appears to leverage a combination of tactics including lateral movement (T1133), service stop (T1489), exploitation of public-facing applications (T1190), data from local system (T1567), remote services (T1021), data destruction (T1491), data manipulation (T1565), valid accounts (T1078), data encrypted for impact (T1486), and data exfiltration (T1490). The absence of known affected software versions or publicly known exploits suggests the adversary may be exploiting zero-day vulnerabilities, supply chain weaknesses, or social engineering vectors to gain initial access. The use of multiple IP addresses and a Tor-based leak site for publishing stolen data indicates a high level of operational security and sophistication, possibly pointing to state-sponsored involvement. The attack has cascading effects on military operations and national security by compromising the integrity and confidentiality of defense supply chains, potentially delaying or degrading defense readiness and exposing strategic defense capabilities to adversaries. This threat highlights the critical need for enhanced cybersecurity frameworks such as CMMC compliance within the defense sector to mitigate risks associated with ransomware and data leaks.

For European organizations involved in defense manufacturing, logistics, or supply chain management supporting national or NATO defense initiatives, Interlock Ransomware poses significant risks. The compromise of sensitive contract and logistics information can lead to operational delays, loss of intellectual property, and exposure of strategic defense capabilities. This undermines national security postures and erodes trust between European defense contractors and governmental clients. The double extortion tactic increases financial and reputational damage, as organizations face ransom demands alongside public data leaks. Disruption of supply chains can ripple across allied military operations, especially given Europe's integrated defense infrastructure. The geopolitical context elevates the threat, as state-sponsored actors may use stolen data for espionage or influence operations. The impact extends beyond immediate operational disruption to long-term strategic vulnerabilities in defense readiness and industrial competitiveness, potentially weakening Europe's defense industrial base and its ability to respond to emerging threats.

European defense organizations should adopt a multi-layered defense strategy tailored to the unique risks posed by Interlock Ransomware: 1) Enforce strict network segmentation separating corporate IT from operational technology (OT) environments to limit lateral movement of ransomware. 2) Conduct comprehensive supply chain risk assessments and mandate cybersecurity requirements, including CMMC or equivalent certification, for all subcontractors and suppliers. 3) Deploy advanced endpoint detection and response (EDR) solutions with behavioral analytics to detect early ransomware indicators such as unusual file encryption or data exfiltration attempts. 4) Implement robust, immutable, and offline backup strategies to enable rapid recovery without paying ransom. 5) Monitor and block known indicators of compromise, including the listed IP addresses and Tor-based domains, at network perimeter and DNS levels. 6) Conduct regular phishing awareness training and simulated social engineering exercises to reduce initial compromise risk. 7) Develop and regularly update incident response plans that include coordination with national cybersecurity agencies and law enforcement, especially to address potential state-sponsored threats. 8) Participate actively in threat intelligence sharing platforms within the European defense community to stay informed on emerging tactics, techniques, and indicators related to Interlock Ransomware. 9) Regularly audit and patch systems, focusing on public-facing applications and remote services to reduce attack surface. 10) Employ multi-factor authentication and strict access controls to reduce risk from compromised credentials.