Threats Tagged 'phantomgraph'

The Head Mare APT group exploited two vulnerabilities in TrueConf video conferencing servers to deliver PhantomCore malware to conference participants. Attackers used these vulnerabilities to execute arbitrary code, replace legitimate client installers with malicious versions, and deploy web shells. When participants downloaded the TrueConf client from compromised servers, they received infected installers that deployed PhantomCore backdoor, granting attackers full control over infected systems. On Linux servers, additional backdoors were installed using GitHub as a command and control channel. The vulnerabilities affected TrueConf server versions released since 2022 and were patched in versions 5.3.9, 5.4.9, and 5.5.5 released in June 2026. Organizations whose employees participated in video conferences using TrueConf may have been affected, even if they don't operate their own TrueConf servers.

The Head Mare APT group exploited a chain of vulnerabilities in TrueConf video conferencing servers to deploy PhantomCore and PhantomGraph backdoors. Attackers connected to unpatched TrueConf servers via port 4307/TCP without authorization, using vulnerabilities KLCERT-26-057 and KLCERT-26-058 to execute arbitrary code with NT AUTHORITY\SYSTEM privileges. They replaced legitimate TrueConf client installers with infected versions containing PhantomCore, and deployed a web shell for persistent access. The PhantomGraph backdoor utilized Microsoft OneDrive as command-and-control infrastructure. Affected TrueConf versions included 5.3.X through 5.3.9, 5.4.X through 5.4.9, and 5.5.X through 5.5.5. Multiple Russian organizations across various industries were targeted, including instrument manufacturing, electronics, transportation, energy, IT, and software development. The vulnerabilities were patched in June 2026.

MediumMalwareBelarusRussia#arcbridge#bridgehead#supply chain attack