Threat Signal Report

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

description-logo 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:

  • Riskware/CoinMiner
  • PossibleThreat


All reported network IOCs in the advisory are blocked by Webfiltering.


FortiGuard Labs has IPS coverage in place for CVE-2021-44228 (Log4Shell):

  • Apache.Log4j.Error.Log.Remote.Code.Execution


Definitions

Traffic Light Protocol

Color When Should it Be used? How may it be shared?

TLP: RED

Not for disclosure, restricted to participants only.
Sources may use TLP:RED when information cannot be effectively acted upon by additional parties, and could lead to impacts on a party's privacy, reputation, or operations if misused. Recipients may not share TLP:RED information with any parties outside of the specific exchange, meeting, or conversation in which it was originally disclosed. In the context of a meeting, for example, TLP:RED information is limited to those present at the meeting. In most circumstances, TLP:RED should be exchanged verbally or in person.

TLP: AMBER

Limited disclosure, restricted to participants’ organizations.
Sources may use TLP:AMBER when information requires support to be effectively acted upon, yet carries risks to privacy, reputation, or operations if shared outside of the organizations involved. Recipients may only share TLP:AMBER information with members of their own organization, and with clients or customers who need to know the information to protect themselves or prevent further harm. Sources are at liberty to specify additional intended limits of the sharing: these must be adhered to.

TLP: GREEN

Limited disclosure, restricted to the community.
Sources may use TLP:GREEN when information is useful for the awareness of all participating organizations as well as with peers within the broader community or sector. Recipients may share TLP:GREEN information with peers and partner organizations within their sector or community, but not via publicly accessible channels. Information in this category can be circulated widely within a particular community. TLP:GREEN information may not be released outside of the community.

TLP: WHITE

Disclosure is not limited.
Sources may use TLP:WHITE when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright rules, TLP:WHITE information may be distributed without restriction.