FBI Links Russian Intelligence to Mass Phishing Campaign Targeting Signal and WhatsApp; Thousands of Accounts Compromised

The FBI and CISA issued a joint alert attributing a global phishing campaign targeting Signal and WhatsApp users to Russian intelligence services. The campaign has compromised thousands of accounts belonging to current and former US government officials, military personnel, political figures, and journalists. Dutch intelligence separately confirmed government employee accounts were breached. Attackers masquerade as app support teams for Signal (harvesting verification codes and PINs) and abuse WhatsApp's linked-devices function to gain persistent access without logging victims out. After compromise, actors can read message history, access contacts, and send messages from trusted identities — enabling lateral phishing at scale.