Federal authorities are offering a reward of up to $10 million for information leading to the identification or location of a Russian state cyber group that has compromised thousands of Signal and WhatsApp accounts belonging to investigative reporters and US government employees.
The operation has been active since at least March, when the FBI published an advisory warning of ongoing phishing campaigns targeting high-value targets by attackers associated with Russian intelligence services. Messages masquerading as automated support communications ask that users click a link or provide verification codes or account passcodes. In the event the user complies, they unknowingly link the attacker’s device to their account or have their account completely taken over and are locked out.
Thousands of accounts already compromised
With that, the attackers can read any new messages sent to the compromised account. A safety feature built into Signal, however, prevents the attackers from reading any previous conversations. The messages are sent to “individuals of high intelligence value, such as current and former US government officials, military personnel, political figures, and journalists.”
Last week, the FBI published an update that said the campaign had evolved. In addition to trying to post as support bots trying to trick recipients into linking their account to an attacker device, the messages also urge users to create a backup of all previous communications following the directions here. A follow-up message then instructs the targets to send the long passcode that’s used to encrypt backups stored on Signal servers. With that, the attackers have access to past Signal conversations. The update said two Russian government groups responsible were tracked as UNC5792 and UNC4221.
