MOUSTACHEDBOUNCER
G1019
BELARUS
APT
Threat IntelligenceAPTJanuary 20, 2026

MoustachedBouncer Threat Profile

Belarusian group targeting foreign embassies in Belarus using ISP-level adversary-in-the-middle attacks for malware delivery.

Belarusian group targeting foreign embassies in Belarus using ISP-level adversary-in-the-middle attacks for malware delivery. This profile is mapped to MITRE ATT&CK G1019 and covers attribution, tooling, targeting, and defensive recommendations based on observed campaigns.

Overview & Attribution

MoustachedBouncer (also tracked as None publicly documented) is a threat group attributed to Belarus. The group primarily targets Foreign diplomats in Belarus for intelligence collection and operational objectives aligned with state interests.

MITRE ATT&CK Reference

This group is tracked as G1019 in the MITRE ATT&CK framework. All techniques referenced in this report are mapped to ATT&CK for consistent threat modeling and detection engineering.

Arsenal & Tools

Known tools and malware associated with MoustachedBouncer include:

Targeting & Operations

MoustachedBouncer operations focus on Foreign diplomats in Belarus. The group typically gains initial access through spear-phishing, exploitation of public-facing applications, or strategic web compromises before deploying custom implants for persistent access and data exfiltration.

Targeting Advisory

Organizations in the Foreign diplomats in Belarus sector should treat MoustachedBouncer as a relevant threat and validate their detection coverage against the MITRE ATT&CK techniques listed below.

MITRE ATT&CK Mapping

Key techniques observed in MoustachedBouncer operations:

Technique IDTechnique NameTactical Context
T1557T1557Observed in MoustachedBouncer campaigns
T1059.001T1059.001Observed in MoustachedBouncer campaigns
T1113T1113Observed in MoustachedBouncer campaigns
T1056.001T1056.001Observed in MoustachedBouncer campaigns

Full ATT&CK mapping: https://attack.mitre.org/groups/G1019/

Notable Campaigns

This threat group has been active in operations targeting Foreign diplomats in Belarus. Security researchers have documented campaigns involving NightClub and other tools deployed against organizations in multiple countries. Attribution confidence varies by campaign, but consistent infrastructure and TTP overlap links activity to Belarus-nexus operations.

Detection & Defense

Recommended defensive measures against MoustachedBouncer:

How Mjolnir Security Can Help

Defend Against MoustachedBouncer

Mjolnir Security provides tailored threat intelligence, detection engineering, and incident response services to help organizations defend against Belarus-nexus threat actors.

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Contact us: mjolnirsecurity.com

Written by: Mjolnir Security  |  Published: January 20, 2026