Threat Signal Report

Joint CyberSecurity Advisory on a U.S. Federal Agency Breached by Iranian Threat Actors

Description

FortiGuard Labs is aware of a joint advisory (AA22-320A) issued by Cybersecurity and Infrastructure security Agency (CISA) and the Federal Bureau of Investigation (FBI) on November 16, 2022. The advisory is related to an Iranian government-sponsored campaign where threat actors breached an unnamed U.S. federal agency and deployed a crypto miner and a hacktool to the compromised network.

Why is this Significant?

This is significant because threat actors backed by the Iranian government compromised a U.S. federal agency and deployed XMRig (crypto miner) and Mimikatz (a post-exploit tool used for credential harvesting).

In February 2022, Iranian threat actors reportedly compromised a federal government agency by exploiting CVE-2021-44228, also known as Log4Shell, in an unpatched VMware Horizon server. This signifies the importance of timely patching of vulnerable systems.

How did the Attack Occur?

The initial infection vector was exploitation of CVE-2021-44228 (Log4Shell) in a vulnerable VMware Horizon server. Once the attacker got a foot in the door to the victim's network, the attacker downloaded and installed XMRig (mining software for Monero cyrptocurrency) after excluding the victim's C:\ drive from scanning by Windows Defender. The attacker leveraged RDP to move laterally to other systems on the victim's network, deployed PsExec (a free Microsoft tool execute processes on other systems) and Mimikatz (an open-source tool for credential harvesting) and implanted Ngrok (a dual use tunneling tool). Also, the attacker accessed the domain controller and retrieved a list of machines that belong to the domain furthering compromise.

What is CVE-2021-44228 (Log4Shell)?

CVE-2021-44228 is a remote code execution vulnerability in the popular Java-based logging utility Log4j2. The vulnerability was disclosed to the public by Apache in early December, however Proof-of-Concept (PoC) code for CVE-2021-44228 was believed to be available earlier.

FortiGuard Labs previously released Outbreak Alert and Threat Signal for CVE-2022-44228. See the Appendix for a link to "Outbreak Alert: Apache Log4j2 Vulnerability" and "Apache Log4J Remote Code Execution Vulnerability (CVE-2021-44228)".

What is the Status of Coverage?

FortiGuard Labs detects the malicious files in the advisory that are available with the following AV signatures: