UK and Allies urge critical sectors to improve defences against Russian intelligence targeting

**Executive summary:** The NCSC and 18 international partners published an advisory attributing opportunistic global router and network-device compromises to Russia's FSB Centre 16 (aka Berserk Bear), which uses SNMP scans, default/weak community strings and known Cisco vulnerabilities to target critical infrastructure; the advisory provides mitigations (use SNMPv3, disable legacy SNMP, enforce strong unique passwords, and restrict management protocol access) and notes coordinated sanctions and formal attribution of a December 2025 attack on Poland's energy grid.