Russian APTs Gamaredon and Turla Join Forces: Kazuar Backdoor Attack on Ukraine (2025)
Executive Summary
In February 2025, cybersecurity researchers observed a coordinated attack on Ukrainian organizations involving collaboration between Russian APT groups Gamaredon and Turla. Utilizing tools such as PteroGraphin and PteroOdd, Gamaredon gained initial access and facilitated the deployment of Turla’s advanced Kazuar backdoor onto a compromised Ukrainian endpoint. This multi-stage intrusion enabled persistent remote access and potential data exfiltration, underscoring a notable escalation in Russian state-sponsored cyber tactics, as adversaries actively combined resources and malware capabilities to maximize operational impact. The attack targeted sensitive Ukrainian infrastructure, heightening concerns over the defense of critical systems.
This incident exemplifies the increasing integration and sophistication among nation-state threat actors, specifically through sharing or chaining malware tools for greater effect. The cooperative tactics and advanced persistence mechanisms highlight the evolving threat landscape and emphasize the urgency for enhanced east-west traffic security, zero trust segmentation, and anomaly detection across critical sectors.
Why This Matters Now
The Gamaredon-Turla collaboration shows state-backed attackers are evolving rapidly, blending tools and resources to overcome siloed cyber defenses. With cross-group cooperation rising, traditional controls may be bypassed, putting organizations—especially those in conflict zones or critical infrastructure—at heightened risk. Immediate focus on visibility, policy enforcement, and segmentation is essential.
Attack Path Analysis
The attack began with Gamaredon leveraging spear-phishing or custom malware (PteroGraphin/PteroOdd) to compromise a Ukrainian endpoint. Attackers then escalated privileges using malicious tools to execute Turla's Kazuar backdoor, likely gaining elevated access. With foothold established, the adversaries performed lateral movement across systems and cloud workloads, searching for high-value assets. Next, they established robust command and control via Kazuar’s encrypted communications, enabling ongoing remote control. Sensitive data was prepared for and potentially exfiltrated through covert or encrypted channels. Finally, by maintaining persistence with backdoors, attackers posed ongoing risks to operational integrity and data confidentiality.
Kill Chain Progression
Initial Compromise
Description
Gamaredon initiated access via spear-phishing or custom malware (PteroGraphin/PteroOdd) targeting Ukrainian endpoints in the cloud or hybrid network.
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Affected Products:
Microsoft Exchange Server – 2013, 2016, 2019
Exploit Status:
exploited in the wild
MITRE ATT&CK® Techniques
Phishing
Command and Scripting Interpreter
Application Layer Protocol
Ingress Tool Transfer
Boot or Logon Autostart Execution
Obfuscated Files or Information
Valid Accounts
Potential Compliance Exposure
Mapping incident impact across multiple compliance frameworks.
PCI DSS 4.0 – Strong Authentication for Remote Access
Control ID: 8.3.1
NYDFS 23 NYCRR 500 – Cybersecurity Policy
Control ID: 500.03
DORA (Digital Operational Resilience Act) – ICT Risk Management Requirements
Control ID: Art. 9(2)
NIS2 Directive – Technical and Organizational Measures
Control ID: Art. 21(2)
CISA Zero Trust Maturity Model 2.0 – Identity and Access Management — Validate All Identities
Control ID: ZE-IA-2
Sector Implications
Industry-specific impact of the vulnerabilities, including operational, regulatory, and cloud security risks.
Government Administration
Ukrainian government entities face direct targeting by Russian APT groups Gamaredon and Turla using Kazuar backdoor, requiring enhanced east-west traffic security and zero trust segmentation.
Defense/Space
Defense infrastructure vulnerable to state-sponsored APT collaboration deploying advanced backdoors, necessitating encrypted traffic protection, threat detection capabilities, and multicloud visibility controls.
Utilities
Critical infrastructure sectors at risk from Russian APT operations targeting Ukraine, requiring robust egress security, anomaly detection, and secure hybrid connectivity to prevent lateral movement.
Telecommunications
Communication networks face compromise from sophisticated APT collaboration using PteroGraphin and PteroOdd tools, demanding inline IPS protection and cloud native security fabric implementation.
Sources
- Russian Hackers Gamaredon and Turla Collaborate to Deploy Kazuar Backdoor in Ukrainehttps://thehackernews.com/2025/09/russian-hackers-gamaredon-and-turla.htmlVerified
- ESET Research: Russian FSB-linked Gamaredon and Turla team up to target high-profile Ukrainian entitieshttps://www.eset.com/us/about/newsroom/research/eset-research-gamaredon-and-turla-target-high-profile-ukrainian-entities/Verified
- Two of the Kremlin’s most active hack groups are collaborating, ESET sayshttps://arstechnica.com/security/2025/09/two-of-the-kremlins-most-active-hack-groups-are-collaborating-eset-says/Verified
- Russian Hacking Groups Gamaredon and Turla Target Organizations to Deliver Kazuar Backdoorhttps://gbhackers.com/russian-hacking-groups/Verified
Frequently Asked Questions
Cloud Native Security Fabric Mitigations and ControlsCNSF
Rigorous application of network segmentation, policy enforcement, and continuous visibility through CNSF-aligned controls would have restricted lateral movement, contained C2 activity, and prevented data exfiltration—substantially constraining the attack's progression and operational impact.
Control: Threat Detection & Anomaly Response
Mitigation: Rapid detection and alerting on anomalous access or malware deployment.
Control: Multicloud Visibility & Control
Mitigation: Centralized visibility exposes privilege abuse events across hybrid and cloud workloads.
Control: Zero Trust Segmentation
Mitigation: Strict microsegmentation blocks unauthorized inter-service movement.
Control: Egress Security & Policy Enforcement
Mitigation: Outbound filtering disrupts C2 establishment to unapproved destinations.
Control: Encrypted Traffic (HPE) & Egress Security
Mitigation: Monitored and controlled egress channels halt unsanctioned data export.
Automated detection of ongoing threats enables remediation before destructive impact.
Impact at a Glance
Affected Business Functions
- Government Operations
- Military Communications
- Critical Infrastructure Management
Estimated downtime: 7 days
Estimated loss: $5,000,000
Potential exposure of sensitive government and military communications, including classified documents and strategic plans.
Recommended Actions
Key Takeaways & Next Steps
- • Enforce zero trust segmentation and microsegmentation to restrict lateral movement between workloads.
- • Implement granular egress controls and centralized policy enforcement to block unauthorized outbound traffic.
- • Deploy continuous threat detection and anomaly response to rapidly identify and contain suspicious behaviors.
- • Ensure all sensitive data in transit is encrypted using high-performance, line-rate encryption.
- • Maintain unified, real-time visibility and control across hybrid, multi-cloud environments for incident readiness.
