Russian intelligence-affiliated hackers have gained access to thousands of users’ messaging apps with a global phishing campaign, the FBI and the Cybersecurity and Infrastructure Security Agency warned in a public service announcement on Friday.
The high-value targets they’re pursuing include current and former U.S. government officials, political figures, military personnel and journalists, the two agencies said in the joint PSA about the hackers’ attempts to infiltrate commercial messaging applications (CMAs).
The U.S. alert comes on the heels of an earlier warning from Dutch authorities, who said last week that Russian hackers were “engaged in a large-scale global attempt” to take over WhatsApp and Signal accounts. The Dutch warning likewise followed a similar warning from Germany in February.
The U.S. agencies emphasized that the hackers had not been able to bypass end-to-end encryption, instead manipulating users into giving up access. The scheme involves hackers posing as Signal help personnel, then inviting them to click a link or provide verification codes or account personal identification number.
“After compromising an account, malicious actors can view the victims’ messages and contact lists, send messages, and conduct additional phishing against other CMA accounts,” the PSA explains. “(Note: reporting shows that the threat actors specifically target Signal accounts but can apply similar methods against other CMAs).”
However, “CMA users who strengthen their personal cybersecurity and defend against social engineering attempts can reduce the risk of account compromise and limit the effectiveness of the threat actors’ current tactics, techniques, and procedures,” the agencies said.
The Russian campaign is just the latest to seek to bypass the protections commercial messaging apps offer. CISA in November warned about spyware targeting of messaging apps.
There sometimes has been a Russian intelligence nexus to the recent targeting. Google Threat Intelligence Group shined a spotlight last year on Russian attempts to target Signal users in Ukraine.
‘We anticipate the tactics and methods used to target Signal will grow in prevalence in the near-term and proliferate to additional threat actors and regions outside the Ukrainian theater of war,” the company said.
