WASHINGTON, March 20 (Reuters) - Hackers tied to the Russian intelligence services are targeting users of consumer messaging applications such as Signal, the FBI and U.S. cyber defense agency CISA said on Friday.
In a joint advisory, the FBI and CISA said that the hackers had successfully broken into thousands of such accounts, without going into detail.
"The activity targets individuals of high intelligence value, such as current and former U.S. government officials, military personnel, political figures, and journalists," the advisory said.
The advisory noted that while the underlying programs and their encryption were not in question, the hackers managed to bypass the apps' security byimpersonating security and tricking users into divulging their security codes.
Signal and the Russian embassy in Washington did not immediately respond to requests for comment.
The U.S. alert echoes a warning issued earlier this month by Dutch intelligence officials, who said that Russian-backed hackers had launched a global cyber campaign to gain access to Signal and WhatsApp accounts used by officials and other intelligence targets.
In response to that warning, Signal said the hacks were"executed via sophisticated phishing campaigns, designed to trick users into sharing information" and that its encryption and infrastructure had not been compromised.
(Reporting by Jasper Ward; Writing by Ismail Shakil; Editing by David Ljunggren and Rosalba O'Brien)
