FBI, CISA warn of Russian hackers hijacking Signal and WhatsApp accounts

The FBI and CISA, supported by European intelligence, warn of an active Russian-linked phishing campaign that impersonates messaging app support to hijack Signal and WhatsApp accounts by adding devices or eliciting verification codes and PINs. Targets include government officials, military personnel, journalists and other high-value individuals, with evidence suggesting thousands of compromised accounts worldwide; the advisories emphasize that end-to-end encryption is not broken, recommend treating in-app support messages as suspicious, enabling registration locks and device-change alerts, never sharing verification codes, and steps to recover if an account is hijacked.