FBI and CISA Warn Russian Intelligence Hijacking Signal and WhatsApp Accounts of High-Value US Targets

FBI and CISA issued a joint advisory warning that Russian Intelligence Services are conducting phishing campaigns to compromise Signal and WhatsApp accounts belonging to current and former US government officials, military personnel, political figures, and journalists. Thousands of accounts have been compromised globally. The attack method does not break end-to-end encryption; instead, operators trick targets into clicking links or sharing verification codes via fake 'Signal Support' accounts. Once access is gained, attackers can view messages and contacts, send messages as the victim, and conduct additional phishing from the trusted identity. The advisory follows heightened Russian intelligence collection against US targets during the Iran conflict.