Google Threat Intelligence Group analyzed STOCKSTAY, a modular .NET backdoor developed and operated by Turla since late 2022, which uses a WebSocket-based C2 channel, RSA/AES encrypted communications, and IPC via WM_COPYDATA between its downloader, orchestrator, tunneler, and backdoor components. STOCKSTAY exhibits strong code, architectural, and obfuscation (K1MORPHER) overlaps with KAZUAR, suggesting a shared development team, and has been deployed via phishing (malicious RDP files, HTA lures) and, most recently, exploitation of CVE-2025-8088 in WinRAR to target Ukrainian military personnel. The actor leverages legitimate hosting platforms (Render, Glitch, GitHub) and compromised third-party/government infrastructure to obscure C2 infrastructure and complicate attribution.
Gamaredon, a Russia-aligned APT group attributed to the FSB, maintained high operational tempo throughout 2025 with 35 spearphishing campaigns exclusively targeting Ukrainian government and military institutions. The group introduced six new PowerShell tools, resurrected the PteroSetup VBScript weaponizer for lateral movement, and began abusing CVE-2025-8088 (WinRAR) for persistence via the Startup folder. A significant infrastructure evolution occurred: C&C servers are now hidden behind tunnel services (Cloudflare tunnels, Cloudflare workers, Microsoft devtunnels, Loophole) and dead-drop resolutions on legitimate platforms (Telegram, Telegra.ph, Rentry, GoFile, Dropbox, and others), while stolen data is exfiltrated to S3-compatible cloud storage (Wasabi, Tebi, Intercolo) rather than attacker-owned servers.
AI Attacked and Abused While Perimeter Authentication Collapses
The month's defining shift was the emergence of AI as a two-sided battlefield: organizations deployed AI tools faster than they secured them, while attackers weaponized the same technology against defenders. Critical flaws in LangGraph allowed SQL injection chained to remote code execution, M365 Copilot could be turned into a one-click data exfiltration weapon via SearchLeak, and Langflow was exploited to deploy cryptominers. Meanwhile, the ongoing Shai-Hulud campaign injected prompts to blind AI malware scanners, macOS.Gaslight turned prompt injection against human analysts, and Russia's APT28 began experimenting with LLM-integrated malware. At the same time, perimeter authentication collapsed at scale: FortiBleed exposed credentials for over 73,000 FortiGate firewalls, CVE-2026-50751 let attackers bypass Check Point VPN authentication entirely, and ShinyHunters exploited an Oracle PeopleSoft zero-day across over 100 organizations.
Supply chain attackers followed developers to their new AI tools, compromising the ecosystems where code is written and built. The Shai-Hulud/Miasma worm expanded from npm into PyPI and injected persistent backdoors into AI coding assistant configurations, while North Korea's Sapphire Sleet compromised over 140 Mastra npm packages to steal cryptocurrency wallets, and the ongoing GlassWorm campaign pivoted to WebAssembly malware in VS Code extensions using the Solana blockchain as command-and-control. Social engineering also industrialized: the ErrTraffic framework turned ClickFix deception into a Malware-as-a-Service operation with blockchain dead drops, and EvilTokens hid phishing flows inside browser-side encryption to defeat network scanners while hijacking Microsoft device-code authentication.
Organizations should treat AI deployments as untrusted perimeter assets—restrict their network access, audit third-party skills and extensions, and assume prompt-injection attacks will target both automated scanners and human analysts. Every internet-facing VPN, firewall, and edge appliance should be patched immediately, with credentials rotated and phishing-resistant MFA enforced, because perimeter authentication failures now cascade directly into internal network compromise.
Multiple Russia-aligned threat actors, including SHADOW-EARTH-066 and Earth Dahu, are actively exploiting a patched WinRAR path traversal vulnerability (CVE-2025-8088) to target Ukrainian organizations. The attackers use crafted RAR archives with NTFS Alternate Data Streams to silently drop malicious payloads, such as the evolved GIFTEDCROOK infostealer or HTA-based espionage tools, into the Windows Startup folder and ProgramData directories.
Trojanized Build Pipelines and Blind-Spot Appliances Redefine the Perimeter
Attackers are bypassing traditional network defenses by compromising the tools developers use to build software and the AI assistants they rely on to write code. Campaigns like Mini Shai-Hulud and Miasma - The Spreading Blight flooded package registries with malicious code that steals cloud credentials and CI/CD tokens, while researchers proved that public AI agent skill marketplaces are completely ineffective at catching malicious add-ons.
Nation-state actors and cybercriminals are simultaneously shifting their focus to blind spots in corporate networks and trusted platforms. The VerdantBamboo group exploited firewalls to bypass conditional access, while UNC3753 used IT impersonation to trick law firm employees into installing remote access tools, and Kali365 expanded its phishing infrastructure to steal multi-factor authentication tokens.
Defenders must shift their focus from perimeter email filtering to securing the software build pipeline and monitoring edge appliances for anomalous traffic. Hunt for unexpected connections to cloud storage APIs and review developer environments for compromised packages or AI skills.
ESET researchers presented evidence of a 2025 espionage alliance between Russian state-aligned actors Gamaredon and Turla targeting Ukraine. Gamaredon utilized its lightweight custom tooling, including PteroGraphin and PteroOdd, to deploy Turla's Kazuar backdoor and maintain persistence for Turla's advanced espionage operations.
Kazuar is a sophisticated, modular P2P botnet attributed to the Russian state-sponsored actor Secret Blizzard. It utilizes a tripartite architecture (Kernel, Bridge, Worker) and a leader election mechanism to minimize external C2 traffic, relying on Mailslots, Window Messaging, and Named Pipes for internal communication and HTTP, WSS, or EWS for external C2.
Over the next two years, Russia is expected to escalate its hybrid warfare against NATO into a coordinated New Generation Warfare (NGW) campaign. This strategy integrates cyber operations, physical sabotage, influence campaigns, and airspace/maritime incursions to degrade European critical infrastructure and political unity while remaining below the threshold of conventional armed conflict.
