The campaign has targeted government personnel as well as individuals of interest to the Russian government, including journalists, the Dutch authorities said. They also emphasized that individual accounts have been compromised, not the messaging apps as a whole.
Signal is used widely by public officials as a secure and independent communications channel, and has been the recommended application for EU officials to use for external comms since 2020.
“Despite their end-to-end encryption option, messaging apps such as Signal and WhatsApp should not be used as channels for classified, confidential or sensitive information,” said the director of the Dutch military intelligence service, Peter Reesink.
United States Secretary of Defense Pete Hegseth and other top U.S. officials came under fire last year for using the app to exchange classified information in an incident known as Signalgate.
WhatsApp’s communication director, Joshua Breckman, said the company continues “to build ways to protect people from online threats ,” adding that users should never share their six-digit code with others.
Signal did not immediately respond to a request for comment. It said in a statement on X it was “aware of recent reports regarding targeted phishing attacks that have resulted in account takeovers of some Signal users.” It added that “Signal’s encryption and infrastructure have not been compromised and remain robust.”
The Russian government did not immediately respond to a request for comment.
This article has been updated to include a statement from Signal.