NCSC’s High-Stakes Warning on State-Sponsored Hijacking of Your Messaging Apps

The National Cyber Security Centre warns that state-sponsored actors, including APT31, IRGC-linked actors, and the FSB-affiliated Star Blizzard, are increasingly abusing consumer messaging apps (WhatsApp, Signal, Messenger) to target high-risk individuals through credential theft, account hijacking, silent device persistence, covert group-chat infiltration, malicious QR codes, and social engineering. The advisory urges stricter hygiene for high-risk users: avoid sharing verification codes, enable two-step verification or registration locks, use corporate messaging for work, audit linked devices and group memberships, and consider disappearing messages while respecting recordkeeping requirements.