A Signal Update Fends Off a Phishing Technique Used in Russian Espionage

Google's threat intelligence revealed that Russia-linked groups UNC5792 and UNC4221 have been using spoofed Signal group-invite QR codes to phish users; when scanned these QR codes linked victims' phones to attacker-controlled devices, allowing real-time interception of end-to-end encrypted messages. Signal released updates to warn users about newly linked devices and require additional authentication to mitigate this social-engineering technique aimed particularly at Ukrainians.