Microsoft Threat Intelligence has disclosed a detailed architectural analysis of Kazuar, an advanced espionage implant operated by Secret Blizzard, a Russian GRU-affiliated threat group. Kazuar has evolved into a modular peer-to-peer botnet with a three-tier node architecture designed to minimize network visibility and outlast traditional detection methods. Organizations operating government, diplomatic, or critical infrastructure environments in Europe, Central Asia, and Ukraine face the highest exposure; the implant’s abuse of Microsoft Exchange as a C2 channel means compromise may already exist in environments without behavioral monitoring.