Russian hackers exploit weak router security to breach critical infrastructure, Western allies warn

Russian state-backed hackers from FSB’s Center 16 are conducting ongoing global intrusions against critical infrastructure by exploiting weakly configured routers, Cisco Smart Install, web management portals and known Cisco vulnerabilities; a joint advisory from the US and 12 partners warns of impacts across communications, energy, defense, finance, government and healthcare and references a December 2025 attempt against Poland’s energy grid that could have affected ~500,000 people, while urging mitigation steps like removing default credentials, restricting management interfaces, and patching/monitoring routers.