SANDWORM 3 MythicRatatoskr An Yggdrasil-enabled Backdoor Deployed in a UAC-0099-Sandworm Collaboration Oct 23, 2026 ESET Research - Sandworm behind cyberattack on Poland’s power grid in late 2025 Jan 24, 2026 Russian hackers, likely linked to Sandworm, exploit legitimate tools against Ukrainian targets Oct 29, 2025