MAR-10135536-21 – North Korean Tunneling Tool: ELECTRICFISH
NotificationThis report is provided "as is" for informational purposes only. The Department of Homeland Security (DHS) does not provide any warranties of any kind regarding any information contained herein. The DHS does not endorse any commercial product or service referenced in this bulletin or otherwise. This document is marked 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. For more information on the Traffic Light Protocol (TLP), see http://www.us-cert.gov/tlp. SummaryDescriptionThis Malware Analysis Report (MAR) is the result of analytic efforts between DHS and the Federal Bureau of Investigation (FBI). Working with U.S. Government partners, DHS and FBI identified a malware variant used by the North Korean government. This malware has been identified as ELECTRICFISH. The U.S. Government refers to malicious cyber activity by the North Korean government as HIDDEN COBRA. For more information on HIDDEN COBRA activity, visit https://www.us-cert.gov/hiddencobra. For a downloadable copy of IOCs, see: Submitted Files (1)a1260fd3e9221d1bc5b9ece6e7a5a98669c79e124453f2ac58625085759ed3bb (a1260fd3e9221d1bc5b9ece6e7a5a9...) Findingsa1260fd3e9221d1bc5b9ece6e7a5a98669c79e124453f2ac58625085759ed3bbDetails
Antivirus
Yara RulesNo matches found. ssdeep MatchesNo matches found. PE Metadata
PE Sections
Packers/Compilers/Cryptors
Process List
DescriptionThis file is a malicious Windows 32-bit executable. The application is a command-line utility and its primary purpose is to tunnel traffic between two IP addresses. The application accepts command-line arguments allowing it to be configured with a destination IP address and port, a source IP address and port, a proxy IP address and port, and a user name and password, which can be utilized to authenticate with a proxy server. It will attempt to establish TCP sessions with the source IP address and the destination IP address. If a connection is made to both the source and destination IPs, this malicious utility will implement a custom protocol, which will allow traffic to rapidly and efficiently be tunneled between two machines. If necessary, the malware can authenticate with a proxy to be able to reach the destination IP address. A configured proxy server is not required for this utility. Screenshots
Figure 1 - Screenshot of the malware authenticating with the proxy server configured at command prompt. Figure 2 - Screenshot of the malware building the authentication packet that will be sent to the destination system. It must begin with the static value "aaaa" for it to be accepted by the utility. Figure 3 - Screenshot of the malware evaluating a received authentication packet. Figure 4 - Screenshot of the malware system authentication packet to the source/destination system. Figure 5 - Screenshot of the authentication packet sent to the source/destination system during analysis. The malware will attempt to tunnel traffic between the source and destination systems specified in the command prompt. Figure 6 - Screenshot of the malware generating two-bytes of random data which will be included in the authentication packet sent to the source/destination systems. Figure 7 - Screenshot of the authentication packet sent to "source" system with lab environment. Malware will attempt to tunnel traffic between the source and destination systems specified at command prompt. RecommendationsCISA recommends that users and administrators consider using the following best practices to strengthen the security posture of their organization's systems. Any configuration changes should be reviewed by system owners and administrators prior to implementation to avoid unwanted impacts.
Additional information on malware incident prevention and handling can be found in National Institute of Standards and Technology (NIST) Special Publication 800-83, "Guide to Malware Incident Prevention & Handling for Desktops and Laptops". Contact Information
CISA continuously strives to improve its products and services. You can help by answering a very short series of questions about this product at the following URL: https://us-cert.gov/forms/feedback/ Document FAQWhat is a MIFR? A Malware Initial Findings Report (MIFR) is intended to provide organizations with malware analysis in a timely manner. In most instances this report will provide initial indicators for computer and network defense. To request additional analysis, please contact CISA and provide information regarding the level of desired analysis. What is a MAR? A Malware Analysis Report (MAR) is intended to provide organizations with more detailed malware analysis acquired via manual reverse engineering. To request additional analysis, please contact CISA and provide information regarding the level of desired analysis. Can I edit this document? This document is not to be edited in any way by recipients. All comments or questions related to this document should be directed to the CISA at 1-888-282-0870 or soc@us-cert.gov. Can I submit malware to CISA? Malware samples can be submitted via three methods:
CISA encourages you to report any suspicious activity, including cybersecurity incidents, possible malicious code, software vulnerabilities, and phishing-related scams. Reporting forms can be found on CISA's homepage at www.us-cert.gov. |
Revisions
May 9, 2019: Initial version|May 14, 2019: Updated IOCs
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