NSA funded MITRE’s research for D3FEND to improve the cybersecurity of National Security Systems, the Department of Defense, and the Defense Industrial Base. MITRE has released a framework for cybersecurity professionals to tailor defenses against specific cyber threats. The framework illustrates the complex interplay between computer network architectures, threats, and cyber countermeasures. MITre released D3fEND as a complement to its existing ATT&CK framework, a free, globally-accessible knowledge base of cyber adversary tactics and techniques based on real-world observations.
Source: https://www.helpnetsecurity.com/2021/06/24/mitre-d3fend/