ShieldBreak: New Windows Zero-Day Bypasses Microsoft’s RoguePlanet Patch
Researcher Chaotic Eclipse published a PoC bypassing Microsoft's CVE-2026-50656 Defender patch, enabling SYSTEM-level code execution on fully patched Windows systems.
Security researcher Chaotic Eclipse released a proof-of-concept for ShieldBreak, a Microsoft Defender zero-day that fully bypasses the patch for CVE-2026-50656 (RoguePlanet), a race condition in the Malware Protection Engine (mpengine.dll) allowing SYSTEM-level code execution. The PoC was tested on Windows 11 25H2 and Windows Server 2025 with a 100% success rate, and Windows 10 is also vulnerable though not supported by the PoC; the flaw may also leak 8 bytes of memory. Microsoft's MSRC had criticized the researcher's repeated uncoordinated disclosures, including YellowKey (BitLocker bypass), GreenPlasma, and LegacyHive (User Profile Service LPE).
Russian State-Sponsored Hackers Use Claude to Rebuild Malware After Detection
Anthropic disrupted APT29-linked GTG-20006, which used Claude to autonomously rebuild malware, hijack hotel Wi-Fi DNS, and target 20-plus Ukrainian, European, and US-linked organizations.
Anthropic attributed the campaign to GTG-20006, aligned with Midnight Blizzard (APT29/Cozy Bear), which developed an AI-driven process that monitors its implants against security products and autonomously rebuilds and redeploys detected malware. Targets included military intelligence, diplomatic, and defense organizations in Ukraine and Europe, plus Middle East and Asian maritime agencies; the actor compromised at least three hotel Wi-Fi vendors via DNS hijacking and served ClickFix lures delivering Windows, Android, and iOS malware such as PowerChrome, GiftDrop, and DarkSword. Operations also included a North African breach exfiltrating over 300,000 national identity records and 500,000-plus company registry entries, an Embassy Kit device-code phishing campaign stealing Microsoft 365 tokens from at least eight organizations, and WhatsApp account takeover using headless browsers. The campaign overlaps with CaptiveCrunch reporting from ReliaQuest, Microsoft, Google, and Lumen Black Lotus Labs.