An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Search
Note: This Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and various ransomware threat actors. These #StopRansomware advisories detail historically and recently observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn about other ransomware threats and no-cost resources.
The United States National Security Agency (NSA), the U.S. Federal Bureau of Investigation (FBI), the U.S. Cybersecurity and Infrastructure Security Agency (CISA), the U.S. Department of Health and Human Services (HHS), the Republic of Korea (ROK) National Intelligence Service (NIS), and the ROK Defense Security Agency (DSA) (hereafter referred to as the “authoring agencies”) are issuing this joint Cybersecurity Advisory (CSA) to highlight ongoing ransomware activity against Healthcare and Public Health Sector organizations and other critical infrastructure sector entities.
This CSA provides an overview of Democratic People’s Republic of Korea (DPRK) state-sponsored ransomware and updates the July 6, 2022, joint CSA North Korean State-Sponsored Cyber Actors Use Maui Ransomware to Target the Healthcare and Public Health Sector. This advisory highlights TTPs and IOCs DPRK cyber actors used to gain access to and conduct ransomware attacks against Healthcare and Public Health (HPH) Sector organizations and other critical infrastructure sector entities, as well as DPRK cyber actors’ use of cryptocurrency to demand ransoms.
The authoring agencies assess that an unspecified amount of revenue from these cryptocurrency operations supports DPRK national-level priorities and objectives, including cyber operations targeting the United States and South Korea governments—specific targets include Department of Defense Information Networks and Defense Industrial Base member networks. The IOCs in this product should be useful to sectors previously targeted by DPRK cyber operations (e.g., U.S. government, Department of Defense, and Defense Industrial Base). The authoring agencies highly discourage paying ransoms as doing so does not guarantee files and records will be recovered and may pose sanctions risks.
For additional information on state-sponsored DPRK malicious cyber activity, see CISA’s North Korea Cyber Threat Overview and Advisories webpage.
Download the PDF version of this report: pdf, 661 kb.
For a downloadable copy of IOCs, see
TECHNICAL DETAILS
Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 12. See MITRE ATT&CK for Enterprise for all referenced tactics and techniques.
This CSA is supplementary to previous reports on malicious cyber actor activities involving DPRK ransomware campaigns—namely Maui and H0lyGh0st ransomware. The authoring agencies are issuing this advisory to highlight additional observed TTPs DPRK cyber actors are using to conduct ransomware attacks targeting South Korean and U.S. healthcare systems.
The TTPs associated with DPRK ransomware attacks include those traditionally observed in ransomware operations. Additionally, these TTPs span phases from acquiring and purchasing infrastructure to concealing DPRK affiliation:
Actors also likely spread malicious code through Trojanized files for “X-Popup,” an open source messenger commonly used by employees of small and medium hospitals in South Korea [T1195].
The actors spread malware by leveraging two domains: xpopup.pe[.]kr and xpopup.com. xpopup.pe[.]kr is registered to IP address 115.68.95[.]128 and xpopup[.]com is registered to IP address 119.205.197[.]111. Related file names and hashes are listed in table 1.
Note: These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the U.S. National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. For more information on the CPGs, including additional recommended baseline protections, see cisa.gov/cpg.
The authoring agencies urge HPH organizations to:
In addition, the authoring agencies urge all organizations, including HPH Sector organizations, to apply the following recommendations to prepare for and mitigate ransomware incidents:
If a ransomware incident occurs at your organization:
Stairwell provided a YARA rule to identify Maui ransomware, and a Proof of Concept public RSA key extractor at the following link:
https://www.stairwell.com/news/threat-research-report-maui-ransomware/
The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, bitcoin wallet information, the decryptor file, and/or benign samples of encrypted files. As stated above, the authoring agencies discourage paying ransoms. Payment does not guarantee files will be recovered and may embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. However, the agencies understand that when victims are faced with an inability to function, all options are evaluated to protect shareholders, employees, and customers.
Regardless of whether you or your organization decide to pay a ransom, the authoring agencies urge you to promptly report ransomware incidents using the contact information above.
NSA, FBI, CISA, and HHS would like to thank ROK NIS and DSA for their contributions to this CSA.
The information and opinions contained in this document are provided “as is” and without any warranties or guarantees. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by the United States Government, and this guidance shall not be used for advertising or product endorsement purposes.
Microsoft Threat Intelligence Center is a registered trademark of Microsoft Corporation. Apache®, Sonicwall, and Apache Log4j are trademarks of Apache Software Foundation. TerraMaster Operating System is a registered trademark of Octagon Systems.
This document was developed in furtherance of the authors’ cybersecurity missions, including their responsibilities to identify and disseminate threats, and to develop and issue cybersecurity specifications and mitigations. This information may be shared broadly to reach all appropriate stakeholders.
System administrators should refer to the SonicWall Security Advisories in the reference section to determine affected applications/systems and appropriate fix actions.
Support for 9.0.0 firmware ended on 10/31/2021. Customers still using that firmware are requested to upgrade to the latest 10.2.x versions.
The IOC section includes hashes and IP addresses for the Maui and H0lyGh0st ransomware variants—as well as custom malware implants assumedly developed by DPRK cyber actors, such as remote access trojans (RATs), loaders, and other tools—that enable subsequent deployment of ransomware. For additional Maui IOCs, see joint CSA North Korean State-Sponsored Cyber Actors Use Maui Ransomware to Target the Healthcare and Public Health Sector.
Table 2 lists MD5 and SHA256 hashes associated with malware implants, RATs, and other tools used by DPRK cyber actors, including tools that drop Maui ransomware files.
Table 3 lists MD5 and SHA256 hashes are associated with Maui Ransomware files.
Table 4 lists MD5 and SHA256 hashes associated with H0lyGh0st Ransomware files.
Df0c7bb88e3c67d849d78d13cee30671b39b300e0cda5550280350775d5762d8
* from Microsoft blog post on h0lygh0st
NSA Client Requirements / General Cybersecurity Inquiries: CybersecurityReports@nsa.gov
Defense Industrial Base Inquiries and Cybersecurity Services: DIB_Defense@cyber.nsa.gov
To report incidents and anomalous activity related to information found in this Joint Cybersecurity Advisory, contact CISA’s 24/7 Operations Center at Report@cisa.gov or (888) 282-0870 or your local FBI field office at www.fbi.gov/contact-us/field. When available, please include the following information regarding the incident: date, time, and location of the incident; type of activity; number of people affected; type of equipment used for the activity; the name of the submitting company or organization; and a designated point of contact.
Media Inquiries / Press Desk:
Leave a Reply