Ember Bear is a Russian state-sponsored cyber espionage group that has been active since at least 2020, linked to Russia's General Staff Main Intelligence Directorate (GRU) 161st Specialist Training Center (Unit 29155). Ember Bear has primarily focused operations against Ukrainian government and telecommunication entities, but has also operated against critical infrastructure entities in Europe and the Americas. Ember Bear conducted the WhisperGate destructive wiper attacks against Ukraine in early 2022. There is some confusion as to whether Ember Bear overlaps with another Russian-linked entity referred to as Saint Bear. At present available evidence strongly suggests these are distinct activities with different behavioral profiles.

Saint Bear is a Russian-nexus threat actor active since early 2021, primarily targeting entities in Ukraine and Georgia. The group is notable for a specific remote access tool, Saint Bot, and information stealer, OutSteel in campaigns. Saint Bear typically relies on phishing or web staging of malicious documents and related file types for initial access, spoofing government or related entities. Saint Bear has previously been confused with Ember Bear operations, but analysis of behaviors, tools, and targeting indicates these are distinct clusters.