An unpatched VMware Horizon server allowed an Iranian government-sponsored APT group to use the Log4Shell vulnerability to not only breach the US Federal Civilian Executive Branch (FCEB) systems, but also deploy XMRing cryptominer malware for good measure.
FCEB is the arm of the federal government that includes the Executive Office of the President, Cabinet Secretaries, and other executive branch departments.
A new update from the Cybersecurity and Infrastructure Security Agency (CISA) said that along with the FBI, the agencies determined the Iranian-backed threat group was able to move laterally to the domain controller, steal credentials, and deploy Ngrok reverse proxies to maintain persistence in the FCEB systems. The attack occurred from mid-June through mid-July, CISA said.
"CISA and FBI encourage all organizations with affected VMware systems that did not immediately apply available patches or workarounds to assume compromise and initiate threat hunting activities," CISA's breach alert explained. "If suspected initial access or compromise is detected based on IOCs or TTPs described in this CSA, CISA and FBI encourage organizations to assume lateral movement by threat actors, investigate connected systems (including the DC), and audit privileged accounts."