Russia-backed hacking groups have developed techniques to compromise encrypted messaging services, including Signal, WhatsApp and Telegram, placing journalists, politicians and activists of interest to the Russian intelligence service at potential risk.

Russia-backed hackers are attempting to compromise Signal’s “linked devices” capability, which allows Signal users to link their messaging account to multiple devices, including phones and laptops, using a quick response (QR) code.

Google threat analysts report that Russia-linked threat actors have developed malicious QR codes that, when scanned, will give the threat actor real-time access to the victim’s messages without having to compromise the victim’s phone or computer.