Chinese Government-linked Cyber Threat Actors Combine Automated and Hands-on ...
Chinese Government-linked Cyber Threat Actors Combine Automated and Hands-on Hacking Tools to Steal Sensitive Data
Chinese government-linked cyber threat actors, enabled by the Integrity Technology Group, are combining automated scanning tools, large-scale botnets, and hands-on exploitation techniques to target and steal sensitive data from organizations worldwide, including US critical infrastructure sectors. These actors exploit vulnerabilities by using scanning tools, cross-site scripting attacks, and password spraying on Microsoft Exchange servers, while establishing persistence through VPN software and exfiltrating emails and credentials using scripts. To help mitigate against this activity, organizations should prioritize disabling unused services and ports, sanitizing web application inputs to prevent injection attacks, implementing multifactor authentication for all services, and applying timely patches to reduce risks of compromise.
Disable unused services and ports , such as automatic configuration, remote access, or file sharing protocols.
Sanitize user input in web applications to prevent possible cross-site scripting (XSS) payload injection.
Implement identity, credential, and access management (ICAM) policies , and then require multifactor authentication (MFA) for services (to the extent possible).
Indicators of Compromise
For a downloadable copy of indicators of compromise, see:
Organizations: Government; Federal Civilian Executive Branch (FCEB); State, Local, Tribal, and Territorial (SLTT); Critical Infrastructure.
Sectors: Government Services and Facilities , Critical Manufacturing , Healthcare and Public Health , and Information Technology .
Roles: Defensive Cybersecurity Analysts , Vulnerability Analysts , Security Systems Managers , Incident Response Analysts
Integrity Technology Group, a China-based company with links to the Chinese government, enables China-linked threat actors to exploit US and foreign organization networks across multiple sectors using various tools and techniques. This advisory provides an analysis of tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) from Integrity Technology Group and the threat actors they enable (hereafter referred to as “the threat actors”). The analysis in this advisory provides network defenders with detection and mitigation guidance to reduce the risk of threat actors compromising critical data.
The threat actors use a unique combination of large-scale botnets, virtual private network (VPN) infrastructure, living-off-the-land (LOTL) techniques, and repositories of computer network exploitation (CNE) tools. Although these techniques are not unique to Chinese threat actors, this advisory details how the threat actors use them to support CNE activity.
The threat actors targeted victims across multiple US critical infrastructure sectors, including: Government Services and Facilities , Critical Manufacturing , Healthcare and Public Health , and Information Technology . The actors also targeted victims in US law enforcement, education, and religious organizations, as well as organizations across Southeast Asia, Africa, and North America.
The information in this advisory originates from technical evidence recovered from, and observed during, multiple Federal Bureau of Investigation (FBI) investigations related to Integrity Technology Group.
The FBI, Cybersecurity and Infrastructure Security Agency (CISA), National Security Agency (NSA), United Kingdom National Cyber Security Centre (NCSC-UK), Australian Signals Directorate’s Australian Cyber Security Centre (ASD’s ACSC), the Canadian Centre for Cyber Security (Cyber Centre), Japan’s National Police Agency (NPA) and National Cybersecurity Office (NCO), New Zealand’s National Cyber Security Centre (NCSC-NZ), and Spain’s Centro Nacional de Inteligencia (CNI), hereafter referred to as “the authoring organizations”—are releasing this joint cybersecurity advisory to urge network defenders from government and relevant organizations to:
Hunt for potential compromises from this activity.
Better protect against this threat activity and other Chinese government-linked cyber targeting.
This advisory also provides our US federal, state, local, territorial, and tribal (FSLTT) government agencies, and international and industry partners, with the indicators and details necessary to proactively defend their networks against this threat and protect critical data.
For more information on People’s Republic of China (PRC) state- malicious cyber activity in general, see the FBI’s Cyber Threat Overview: China webpage. For more information on China-linked malicious cyber activity, see CISA’s People’s Republic of China Threat Overview and Advisories webpage.
The authoring organizations encourage network defenders to implement the recommendations in the Mitigations section of this advisory to reduce the likelihood and impact of these incidents.
Download the PDF version of this report:
For a downloadable copy of IOCs, see:
Threat Actor Background
Integrity Technology Group (Integrity Tech) is a China-based for-profit company with links to the Chinese government. Integrity Tech employs individuals who support malicious cyber activity in different ways, including acquiring or building cyber tools for use and sale, acquiring and hosting infrastructure, and compromising networks across global victims, which the authoring organizations track as China-based malicious cyber activity. The services provided by Integrity Tech also contribute to the larger Chinese cyber ecosystem, which aims to exfiltrate sensitive data from victims around the world.
Notably, the threat actors enabled by Integrity Tech use TTPs consistent with the cyber activity publicly known as Flax Typhoon, Ethereal Panda, and Red Juliett, among others. However, these threat actors may also perform activity not associated with Integrity Tech.
Note: Cybersecurity companies have different methods of tracking and attributing cyber actors and these may not be a 1:1 correlation to the US Government's methodology and understanding for all activity related to these groupings.
Note: This advisory uses the MITRE ATT&CK ® Matrix for Enterprise framework, version 19. See Appendix A: Indicators of Compromise and the MITRE ATT&CK Tactics and Techniques section of this advisory for a table of the threat actors’ activity mapped to MITRE ATT&CK tactics and techniques.
The threat actors use a variety of open source scanning tools to find vulnerabilities in networks and web-based applications, including: BBScan, dirsearch, Fscan, ksubdomain, masscan, NMAP, OneForAll, ShuiZe, and wpscan [ T1595.002 ]. See Appendix A: Indicators of Compromise for a complete list of scanning tools.
Some of these tools contain features useful for fingerprinting remote applications, testing remote authentication protocols, or enumerating the pages of a website. The use of open source tools typically found on GitHub suggests the threat actors tend to look for more vulnerable targets. In general, the threat actors focus on scanning ports 21 (file transfer protocol [FTP]), 22 (SSH), 53 (domain name system [DNS]), 80 (HTTP), 443 (HTTPS), and 1080 (SOCKS). When scanning websites with dirsearch, the threat actors attempt to enumerate PHP and ASP ( .NET ) pages.
As early as 2017, these threat actors have also used a malicious application known as “MicroScan.” This Python-based web application contains over 1,300 penetration testing scripts written to scan websites for specific vulnerabilities. The threat actors used these scripts to target services including OpenSSL, Oracle WebLogic, Rejetto, WordPress, Juniper ScreenOS, Jenkins, and Apache Struts. See Appendix B: Observed Common Vulnerabilities and Exposures for a list of successfully exploited common vulnerabilities and exposures (CVEs) recovered from penetration testing scripts. Figure 1 shows a MicroScan account dashboard displaying detected vulnerabilities.
Initial Access and Execution
Since at least mid-January 2021, the threat actors have gained access to victim networks and cloud-based services primarily through command line utilities built on exploit codes written in popular programming languages, such as Python and Go [ T1059.006 ]. Additionally, the threat actors have used JavaScript [ T1059.007 ] and HTML code to execute cross-site scripting (XSS) attacks. XSS vulnerabilities allow malicious actors to use unwitting third-party applications vulnerable to XSS to modify content on a webpage [ T1189 ] and target other victims.
During the investigations, the FBI recovered an XSS payload used by the threat actors. When executed on a vulnerable website running JavaScript, this payload modifies webpage content to display username and password fields, facilitating user credential harvesting (see Figure 2 ).
After a user enters any username and password, the executed XSS payload page generates a link to download a password-protected .zip file. The .zip file’s contents originate from encoded bytes within the XSS payload and contain the executable file live700_v1.exe .
Analysis of live700_v1.exe demonstrated the executable begins a process named DiagTrack.exe , which shares its name with legitimate Windows software [ T1036.003 ]. DiagTrack.exe then establishes encrypted communications over the HTTP protocol with the domain dns.studiocloud.xyz , which the FBI attributes to Integrity Tech. Given that the executable also contains functions designed to query data from user mailboxes, the FBI assesses the malware likely targets user email data for exfiltration.
The threat actors use EBurst, an open source Python-based tool, to target accounts in the Microsoft Office365 Cloud environment. The tool compromises email accounts on Microsoft Exchange servers using multiple interfaces for password spraying [ T1110.003 ] and password guessing [ T1110.001 ] against each supplied email address. Based on the open source EBurst ReadMe file, these interfaces include:
Exchange Control Panel (ECP);
Exchange Web Services (EWS);
Offline Address Book (OAB);
Outlook Web Access (OWA);
Remote Procedure Call (RPC);
Application Programming Interface (API);
Messaging Application Programming Interface (MAPI);
Microsoft-Server-ActiveSync.
Network defenders should include these interfaces when defending against EBurst.
To establish persistence, the threat actors install virtual private network (VPN) software clients on victim devices [ T1133 ] to obfuscate command and control (C2) communications or other actions, further preventing victims from attributing malicious network activity.
The threat actors typically download SoftEther installers onto victim devices from threat actor-controlled infrastructure using PowerShell or LOTL binaries for Windows Systems [ T1059.001 ]. For Linux/Unix distributions, the threat actors download SoftEther installers via curl or wget . For either operating system, the actors configure the SoftEther client to automatically reconnect on startup. They often name the installers conhost.exe or dllhost.exe to appear as common Windows executables [ T1036.003 ]. Additionally, endpoint detection software is less likely to flag SoftEther because it is a legitimate VPN software.
In some observed cases, the threat actors stored the SoftEther program directly on the server. Analysis of these servers revealed victim domains and subdomains that hosted the SoftEther connections:
javacheck.ooguy[.]com;
javaupdate.giize[.]com;
The threat actors use SoftEther to maintain persistent remote access to victim devices to enable data exfiltration. The FBI observed the threat actors installing the client on the end-user’s system, which connected to the C2 server using one of the identified domains, subdomains, or the server’s IP address. The threat actors also accessed other targets, including cybersecurity websites, connected to these hubs.
Collection and Exfiltration
The FBI observed the threat actors downloading databases or manually pulling data from the victim emails and staging the exfiltration data with discreet file names to minimize detection of the MySQL email dump. Some of these names include:
All_scanner_vXX.pl.gz (XX represents either a one- or two-digit number);
The FBI observed that the threat actors created a bot using the PHP script Curlc4.txt to obtain emails from victims. The script is specifically designed to interface with the Microsoft EWS API, which allows the threat actors to access email and content items, such as calendars and contacts [ T1114.002 ].
Based on observations, the script appears to be stand-alone rather than installed on a compromised device. The script uploaded emails to a remote server [ T1020 ], obfuscating many of the directories and files it created, and changed the name of the child process to crypto .
The script downloaded the original file from using IP address 149.28.132[.]137 . The main C2 domain for the bot was natcloudservice[.]com, and the domain communicated with and upl.natcloudservice[.]com/ews. Before exfiltration, the bot compressed emails. In some instances, the threat actor also used a password to encrypt emails using RC4 or AES-128-CBC [ T1560.003 ].
The PHP script took up to two command-line arguments. The first argument appeared to be the root directory where the scripts execute. If the first argument was not supplied, then the script searched for a writeable directory [ T1074.001 ] to use as its directory. The script searched the directories listed in Table 1 until it found a writeable one. The script stored the second command-line argument in a variable saved to the targeted system.
Subdirectories to Skip
/bin, /boot, /dev, /etc, /run, /proc, /sys, /var, /tmp, /usr
The following is a list of unique strings found in the script:
$dir/storage/fm/.run;
public $password='jh4jnryw76ikmh';
public $file='/var/tmp/.sess.zip';
public $key='rhnr5m54pk65wertc';
$this->enc="r";this->cipher="rc4";this->iv="";
$this->enc="a";this->cipher="aes-128-cbc";this->iv="1111111111111111";
; and
curl_setopt($this->ch, CURLOPT_HTTPHEADER,array("X-Id: $clientid")).
Other directories and files that indicate this script may be executed on a system include:
RUNNING_DIRECTORY/storage/fm ;
RUNNING_DIRECTORY /storage/fm.run (file);
RUNNING_DIRECTORY /.run ;
RUNNING_DIRECTORY/clientid (file); and
RUNNING_DIRECTORY/cp (file).
The threat actors used DC.exe to execute the DCSync replication technique [ T1003.006 ] to copy sensitive information from the Active Directory (AD), including account credentials, group membership details, and trust relationships. DC.exe used a Remote Procedure Call (RPC) binding to the victim’s domain controller. The file then used the Directory Replication Service to retrieve data from the victim’s AD. Specifically, it retrieved a handle to the local security policy object, which is used to query the domain controller for the DNS domain name, domain security identifier (SID), and domain replication epoch. The file also used the following object IDs to retrieve information Active Directory attributes and configurations:
1.2.840.113556.1.2.48;
1.2.840.113556.1.4.1;
1.2.840.113556.1.4.125;
1.2.840.113556.1.4.129;
1.2.840.113556.1.4.133;
1.2.840.113556.1.4.135;
1.2.840.113556.1.4.146;
1.2.840.113556.1.4.159;
1.2.840.113556.1.4.160;
1.2.840.113556.1.4.221;
1.2.840.113556.1.4.27;
1.2.840.113556.1.4.302;
1.2.840.113556.1.4.55;
1.2.840.113556.1.4.609;
1.2.840.113556.1.4.656;
1.2.840.113556.1.4.8;
1.2.840.113556.1.4.90;
1.2.840.113556.1.4.94; and
1.2.840.113556.1.4.96.
The FBI recovered an archived email database the threat actors used to target email accounts of victim organizations. The threat actors collect account credentials and exfiltrate victim email data from on-premise systems and cloud-based services. Observed victims of email data theft included government organizations, law enforcement agencies, healthcare systems, and religious institutions located in Southeast Asia. In some instances, the threat actors restricted access to the exfiltrated data to only IP addresses from Xiamen, China.
The threat actors use a command-line utility office-cli [ T1059.004 ] to continuously target and access Microsoft Outlook 365 email accounts to exfiltrate emails across different time periods. The threat actors occasionally update these accounts and swap them for the most recent accounts. The threat actors use office-cli to automate access and exfiltration of mail content using configuration files, such as client_id , tenant_id , and secret .
The FBI observed the threat actors executing office-cli from the command line or by running it from a Bash script. In both instances, the threat actors place the JSON files required to access the mailboxes in the config directory. Additionally, office-cli saves data gathered from the victims in a subdirectory of the dump directory. The threat actors evade detection when using this program by using legitimate access methods.
The threat actors maintain a custom web application that provides third-party access to stolen email content. Users of this application can pass specific arguments in URLs to see email content for specific accounts.
Indicators of Compromise
See Appendix A: Indicators of Compromise for a list of all observed indicators.
MITRE ATT&CK Tactics and Techniques
See Table 2 to Table 9 for all referenced threat actor tactics and techniques in this advisory. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool .
Active Scanning: Vulnerability Scanning
The threat actors leverage several scanning tools to find vulnerabilities in networks and web-based applications.
The threat actors execute XSS attacks to leverage an unwitting third-party application to modify content on a webpage.
Command and Scripting Interpreter: PowerShell
The threat actors typically download SoftEther installers onto victim devices from threat actor controlled infrastructure using PowerShell.
Command and Scripting Interpreter: Unix Shell
The threat actors use office-cli , a Linux-based binary, to continuously target and access Microsoft Outlook 365 accounts. Office-cli automates exfiltration of mail content using configuration files, including account credentials.
Command and Scripting Interpreter: Python
The threat actors gain access to victim networks and cloud-based services primary through command-line utility tools based on exploit codes written in Python.
Command and Scripting Interpreter: JavaScript
The threat actors use JavaScript to execute XSS attacks.
External Remote Services
The threat actors install VPN software clients on victim devices to establish persistence and obfuscate C2 communications.
Masquerading: Rename Legitimate Utilities
The threat actors run executables with the same name of a known, legitimate Windows software and installers to evade detection.
OS Credential Dumping: DCSync
The threat actors use DC.exe to execute the DCSync replication technique to copy sensitive information from the Active Directory.
Brute Force: Password Guessing
The threat actors use eburst.py to conduct password guessing to compromise email accounts on Microsoft Exchange servers.
Brute Force: Password Spraying
The threat actors use eburst.py to conduct password spraying to compromise email accounts on Microsoft Exchange servers.
Email Collection: Remote Email
The threat actors use the PHP script to interface with the Microsoft EWS API, enabling them to access email and content items.
Archive Collection Data: Archive via Custom Method
The threat actors use a custom bot to compress, and in some cases encrypt, files prior to exfiltration.
Data Staged: Local Data Staging
The PHP script searches for a writeable directory to use as its directory.
Automated Exfiltration
The threat actors leverage the PHP script to automatically upload emails to a remote server.
If a potential compromise is detected, organizations should take the following actions:
Determine which hosts were compromised and isolate them by quarantining or taking them offline.
Initiate threat hunting activities to scope the intrusion. Collect and review relevant artifacts, logs, and other data to identify threat actor TTPs, compromised devices and accounts, a timeline of activity, etc.
Collect and review relevant artifacts, logs, and other data to identify threat actor TTPs, compromised devices and accounts, a timeline of activity, etc.
Follow national guidelines and requirements in your country on reporting cyber incidents (see Information ).
Apply eviction countermeasures to contain the incident and eradicate the threat actor from the network. Start applying countermeasures after collecting enough threat hunting data to inform effective countermeasure selection; this will likely overlap with threat hunting activities): Use CISA’s Eviction Strategies Tool to assemble countermeasures for a systematic eviction plan—the tool comprises Playbook-NG (a web application) and COUN7ER (a database of post-compromise countermeasures mapped to adversary TTPs). Use Playbook-NG and COUN7ER together to assemble a systematic eviction plan, or playbook, that leverages distinct countermeasures to contain and evict cyber threat actors. The playbook features a list of recommended response actions based on threat actor TTPs and includes each action’s intended outcome, preparatory steps, and associated risks. For more information, see CISA’s Eviction Strategies Tool Fact Sheet .
Start applying countermeasures after collecting enough threat hunting data to inform effective countermeasure selection; this will likely overlap with threat hunting activities):
Use CISA’s Eviction Strategies Tool to assemble countermeasures for a systematic eviction plan—the tool comprises Playbook-NG (a web application) and COUN7ER (a database of post-compromise countermeasures mapped to adversary TTPs). Use Playbook-NG and COUN7ER together to assemble a systematic eviction plan, or playbook, that leverages distinct countermeasures to contain and evict cyber threat actors. The playbook features a list of recommended response actions based on threat actor TTPs and includes each action’s intended outcome, preparatory steps, and associated risks. For more information, see CISA’s Eviction Strategies Tool Fact Sheet .
Use Playbook-NG and COUN7ER together to assemble a systematic eviction plan, or playbook, that leverages distinct countermeasures to contain and evict cyber threat actors.
The playbook features a list of recommended response actions based on threat actor TTPs and includes each action’s intended outcome, preparatory steps, and associated risks. For more information, see CISA’s Eviction Strategies Tool Fact Sheet .
Harden the network to prevent additional malicious activity (see Mitigations for guidance).
The authoring organizations recommend network defenders and organizations implement the mitigations below to improve your organization’s cybersecurity posture on the basis of the threat actors’ activity. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the 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 and TTPs. Visit CISA’s CPGs webpage for more information on the CPGs, including additional recommended baseline protections.
The authoring organizations recommend network defenders and organizations implement these mitigations:
Disable unused services and ports , such as automatic configuration, remote access, or file sharing protocols. Configure applications to reveal as little information as possible when serving login pages or banner information in response to external requests. Consider using an attack surface management service or web-based platforms that the internet to identify exposed services or ports [ CPG 3.S ]. For additional support, follow CISA’s Internet Exposure Reduction Guidance and NSA’s Attack Surface Management .
Configure applications to reveal as little information as possible when serving login pages or banner information in response to external requests.
Consider using an attack surface management service or web-based platforms that the internet to identify exposed services or ports [ CPG 3.S ]. For additional support, follow CISA’s Internet Exposure Reduction Guidance and NSA’s Attack Surface Management .
Sanitize user input in web applications to prevent possible XSS payload injection.
Implement identity, credential, and access management (ICAM) policies across the organization and then require multifactor authentication (MFA) [ CPG 3.F ] for all services (to the extent possible), particularly for webmail, VPNs, and accounts that access critical systems.
Replace default passwords with strong passwords [ CPG 3.A ]. Limit and audit user accounts with administrative privileges and configure access controls with least privilege in mind. Ensure only users that need administrator privileges are granted these privileges, and regularly review access to assess whether it is still required [ CPG 3.G ].
Limit and audit user accounts with administrative privileges and configure access controls with least privilege in mind.
Ensure only users that need administrator privileges are granted these privileges, and regularly review access to assess whether it is still required [ CPG 3.G ].
Enable download and domain reputation screening in web browsers, along with protective DNS resolution, to block downloads of known malware and connections to websites and domains with unsafe reputations.
Monitor for signs of unauthorized use of LOTL tools and unexpected Active Directory replication [ CPG 4.B ].
Implement network segmentation to ensure a compromised device has no access to sensitive resources of another organizational unit [ CPG 3.I ]. Use the principle of least privilege to provide just enough connectivity for devices to perform their intended functions [ CPG 3.H ]. For a less resource constrictive mitigation, organizations may segment edge devices internally.
Use the principle of least privilege to provide just enough connectivity for devices to perform their intended functions [ CPG 3.H ].
For a less resource constrictive mitigation, organizations may segment edge devices internally.
Monitor cloud accounts for connected applications that can access sensitive data in file systems and email data.
Review web application access logs for signs of exploitation attempts , such as malicious directory traversal attempts, command injection attempts, or enumeration attempts [ CPG 3.Q ].
Apply patches and updates , including software and firmware updates (regular patching mitigates many high-risk security vulnerabilities) [ CPG 2.B ]. If available, use automatic update channels from trusted network locations. Do not trust email messages claiming to provide software updates as attachments or via links to untrusted websites.
If available, use automatic update channels from trusted network locations.
Do not trust email messages claiming to provide software updates as attachments or via links to untrusted websites.
Install and regularly update antivirus software on all hosts and enable real time detection.
Monitor for abnormal and high volumes of unexpected traffic (scanning) using firewalls and/or intrusion detection systems [ CPG 4.B ]. Since an attempted compromise using a distributed denial of service (DDoS) technique may appear as normal traffic, it is critical for organizations to define, monitor, and prepare for abnormal traffic volumes.
Since an attempted compromise using a distributed denial of service (DDoS) technique may appear as normal traffic, it is critical for organizations to define, monitor, and prepare for abnormal traffic volumes.
Monitor for high volumes of outbound or upload traffic from workstations or other devices that usually have low volumes of uploads compared to downloads.
Monitor logs and investigate unusual IP addresses and ports in command lines, registry entries, and firewall logs to identify other hosts that are potentially involved in actor actions [ CPG 3.Q ]. Review perimeter firewall configurations for unauthorized changes and/or entries that may permit external connections to internal hosts.
Review perimeter firewall configurations for unauthorized changes and/or entries that may permit external connections to internal hosts.
Monitor for abnormal account activity , such as logons outside of normal working hours and impossible time and distance logons (e.g., a user logging on from two geographically separated locations at the same time) [ CPG 4.B ].
Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (i.e., hard drive, storage device, or the cloud) [ CPG 1.C ].
Regularly back up data and password protect backup copies offline [ CPG 3.O ]. Ensure copies of critical data are not accessible for modification or deletion from the system where data resides.
Ensure copies of critical data are not accessible for modification or deletion from the system where data resides.
Replace end-of-life products with supported alternatives that are included in vendor support plans.
Ensure systems use the strongest feasible form of authentication [ CPG 3.B ; CPG 3.F ].
Harden authentication protocols and access lists [ CPG 3.H ]. Regularly rotate keys for your service accounts, use strong key lengths to enhance security and minimize the risk of key compromise, and implement role-based access control (RBAC) to avoid granting excess privileges.
Regularly rotate keys for your service accounts, use strong key lengths to enhance security and minimize the risk of key compromise, and implement role-based access control (RBAC) to avoid granting excess privileges.
Provide cyber security awareness and training [ CPG 3.J ]. Regularly train users on information security principles and techniques, as well as overall emerging cybersecurity risks and vulnerabilities (e.g., ransomware and phishing scams).
Regularly train users on information security principles and techniques, as well as overall emerging cybersecurity risks and vulnerabilities (e.g., ransomware and phishing scams).
Regularly engage reputable and skilled penetration testing services to evaluate your public attack surface and remediate the most commonly exploited vulnerabilities used by these actors.
Validate Security Controls
In addition to applying mitigations, the authoring organizations recommend exercising, testing, and validating your organization's security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. The authoring organizations recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.
Select an ATT&CK technique described in this advisory (see Table 2 to Table 9 ).
Align your security technologies against the technique.
Test your technologies against the technique.
Analyze your detection and prevention technologies’ performance.
Repeat the process for all security technologies to obtain a set of comprehensive performance data.
Tune your security program, including people, processes, and technologies, based on the data generated by this process.
The authoring organizations recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.
For more information on attack surface management, see: CISA’s Internet Exposure Reduction Guidance ; CISA’s Cyber Hygiene Services for US critical infrastructure; and NSA’s Attack Surface Management for the US Defense Industrial Base (DIB).
CISA’s Internet Exposure Reduction Guidance ;
CISA’s Cyber Hygiene Services for US critical infrastructure; and
NSA’s Attack Surface Management for the US Defense Industrial Base (DIB).
For additional information on the UK’s National Cyber Security Centre’s (NCSC-UK’s) resources see: Network Security Fundamentals ; Protective DNS Service ; Guidance Selecting Right Methods to Authenticate Customers ; Guidance Ransomware-Resistant Backups ; and Penetration testing guidance, see Penetration Testing .
Network Security Fundamentals ;
Protective DNS Service ;
Guidance Selecting Right Methods to Authenticate Customers ;
Guidance Ransomware-Resistant Backups ; and
Penetration testing guidance, see Penetration Testing .
For more information on sanitizing user input, see: CISA’s Secure by Design Alert: Eliminating Cross Site Scripting Vulnerabilities ; The Open Worldwide Application Security Project’s (OWASP) Input Validation Cheat Sheet ; and OWASP’s Cross-Site Scripting Prevention Cheat Sheet .
CISA’s Secure by Design Alert: Eliminating Cross Site Scripting Vulnerabilities ;
The Open Worldwide Application Security Project’s (OWASP) Input Validation Cheat Sheet ; and
OWASP’s Cross-Site Scripting Prevention Cheat Sheet .
For more information on protective DNS (PDNS), see: NSA and CISA’s guidance Selecting a Protective DNS Service ; and NSA’s Protective DNS Service offerings for the US Defense Industrial Base.
NSA and CISA’s guidance Selecting a Protective DNS Service ; and
NSA’s Protective DNS Service offerings for the US Defense Industrial Base.
For more information on LOTL, see ASD’s ACSC and CISA’s joint guidance Identifying and Mitigating Living Off the Land Techniques .
For more information on defending Active Directory, see ASD’s ACSC’s joint guidance Detecting and Mitigating Active Directory Compromises .
For more information on Canadian Cyber Centre resources, see: Phishing-resistant MFA ; Top 10 security actions on network segmentation ; Top 10 security actions for patching OS and applications ; Obsolete products (end-of-life); Preventative security tools ; and Best practices with passphrases and passwords .
Phishing-resistant MFA ;
Top 10 security actions on network segmentation ;
Top 10 security actions for patching OS and applications ;
Obsolete products (end-of-life);
Preventative security tools ; and
Best practices with passphrases and passwords .
US organizations are encouraged to report suspicious or criminal activity related to information in this advisory to the FBI, CISA, and/or NSA:
File a claim with FBI’s Internet Crime Complaint Center (IC3) or your local FBI field office , or CISA via CISA’s 24/7 Operations Center at @cisa.dhs.gov or 1-844-Say-CISA (1-844-729-2472). 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; and Name of the submitting company or organization, and a designated point of .
Date, time, and location of the incident;
Number of people affected;
Type of equipment used for the activity; and
Name of the submitting company or organization, and a designated point of .
For NSA cybersecurity guidance inquiries, [email protected] .
United Kingdom organizations: Report a significant cyber security incident at ncsc.gov.uk/report-an-incident (monitored 24 hours) or, for urgent assistance, call 03000 200 973.
Australian organizations: Visit cyber.gov.au or call 1300 292 371 (1300 CYBER 1) to report cybersecurity incidents and access alerts and advisories.
Canadian organizations: Report incidents by emailing the Canadian Centre for Cyber Security (Cyber Centre) at @cyber.gc.ca , (613) 949-7048, or 1-833-CYBER-88.
Japan organizations: Report an incident to the National Cybersecurity Office (NCO) via email at [email protected] or the National Police Agency’s (NPAs) web portal at .
New Zealand organizations: Visit ncsc.govt.nz or call 0800 114 115 to report cyber security incidents.
The information in this report is being provided “as is” for informational purposes only. The authoring organizations do not endorse any commercial entity, product, company, or service, including any entities, products, or services linked within this document. Any reference to specific commercial entities, products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by the authoring organizations.
October 8, 2026 : Initial version.
Appendix A: Indicators of Compromise
See Table 10 to Table 15 for a list of observed IOCs. The IOCs listed in the appendices may or may not be addressed in detail in the body of this document; however, endpoint detection systems can ingest all of these IOCs to help mitigate threat activity.
Disclaimer: Several of the observed IOCs date back to as early as 2016. The authoring organizations recommend investigating or vetting these IOCs prior to taking action, such as blocking.
Note: The first and last dates are included in this table, with an asterisk (*) denoting the WHOIS registry expiration date specified within.
_msdcs.cktime.ooguy[.]com
1421.client.96html[.]com
1421.cloud.96html[.]com
1421.support.96html[.]com
154-119-131-252-103-58-216-162-36.m.secshow[.]net
2-12-44-140-78-81-211-109-241.h.secshow[.]net
22852.careers.96html[.]com
22852.careers.trendmicro.96html[.]com
22852.trendmicro.96html[.]com
23175.careers.96html[.]com
23175.careers.trendmicro.96html[.]com
2637596418.softether[.]net
28394.careers.96html[.]com
28394.careers.trendmicro.96html[.]com
28394.trendmicro.96html[.]com
28733.careers.trendmicro.96html[.]com
28733.trendmicro.96html[.]com
35584.careers.96html[.]com
35584.careers.trendmicro.96html[.]com
35584.trendmicro.96html[.]com
39583.b.alitagotest[.]cf
44673.careers.96html[.]com
44673.trendmicro.96html[.]com
47298.client.96html[.]com
47298.cloud.96html[.]com
47298.support.96html[.]com
50669.careers.trendmicro.96html[.]com
51640.careers.trendmicro.96html[.]com
54-2-32-236-208-2-40-107-38.h.secshow[.]net
66-37-178-96-110-2-40-107-38.h.secshow[.]net
74788.careers.96html[.]com
74788.trendmicro.96html[.]com
77692.careers.96html[.]com
77692.careers.trendmicro.96html[.]com
77692.trendmicro.96html[.]com
82262.careers.96html[.]com
82262.careers.trendmicro.96html[.]com
85005.careers.96html[.]com
85005.careers.trendmicro.96html[.]com
85005.trendmicro.96html[.]com
90174.careers.96html[.]com
90174.careers.trendmicro.96html[.]com
96976.careers.96html[.]com
96976.trendmicro.96html[.]com
bbs.sunmoon[.]website
careers.trendmicro.96html[.]com
csrfproxy.studiocloud[.]xyz
dc-29465b27aa45.96html[.]com
dc-4fe9871cb224.96html[.]com
dc-582fc0f46da9.96html[.]com
dc-843d98722400.96html[.]com
dc-bb503834b7dc.96html[.]com
dc-c11a983d7f83.96html[.]com
dns.studiocloud[.]xyz
etechhosting.twimg.co[.]uk
gate.sinica.edu.tw.checkapi[.]cf
halloween.checkapi[.]cf
hook.studiocloud[.]xyz
imap.sunmoon[.]website
iplc-hk.hmbcloud[.]com
javacheck.ooguy[.]com
javaupdate.giize[.]com
live.studiocloud[.]xyz
mail.bailbonding[.]info
mail.sunmoon[.]website
natcloudservice[.]com
ns1.honey1314520[.]com
pdc._msdcs.cktime.ooguy[.]com
random.cktime.ooguy[.]com
s3crts.softether[.]net
smtp.sunmoon[.]website
szxcm-hkg01.iepl.node[.]cm
trendmicro.96html[.]com
txt.studiocloud[.]xyz
upgrate.checkapi[.]cf
upl.natcloudservice[.]com
vpn328433596.softether[.]net
vpn614174689.softether[.]net
vpn677190427.softether[.]net
vpn718535264.softether[.]net
vpn823494147.softether[.]net
wanfang.accesscam[.]org
webdisk.bailbonding[.]info
webmail.studiocloud[.]xyz
wss.studiocloud[.]xyz
xassxxdns.alitagotest[.]cf
ximmd.sexytube0[.]com
zerogravity1986.softether[.]net
Table 12 shows observed domain names attributed to this threat activity and obfuscation network hosts.
dns.studiocloud[.]xyz
etechhosting.twimg.co[.]uk
iplc-hk.hmbcloud[.]com
javacheck.ooguy[.]com
javaupdate.giize[.]com
szxcm-hkg01.iepl.node[.]cm
ximmd.sexytube0[.]com
Table 13 contains known webshells from the threat actor’s repository of CNE tooling, which may appear on a compromised system. The threat actors have used these webshell files for unauthorized access to victim environments.
MD5: 48ca18a25424a0f52276290b619a7a83
SHA-256: 72c6af6a4be99e31c4a7a0aa4f01750792788e7f6f9749243a9f2c47c14a708f
MD5: 38f5ff8169423e2c756848c02e8cac3b
SHA-256: 456586ababa08f70216c4459f4d6375676166ebfddd98a33b447ceb5099e8dc5
MD5: d61326c4e6d24aa9b67e2b7a3ef7cedf
SHA-256: 2f5c406eb64ad8902c8e30610d43fd3efc05a14cdb8fb158818953eaf3dc6a81
MD5: f8de2e99dc7523d2c83d1a48e844c5ff
SHA-256: 5782ff2c835c88cc1ee521d2e8c523cfad73db3f9a29c93b40c4223f0338ade9
MD5: 5b5a2c7fa705d8b1eb04da5db900b0d7
SHA-256: 0e6fecb2d369b0eae63731616a3daada52036634885ab1b85b115af6bc5bcb86
MD5: 655cd134976d3e80c521708aa8be418b
SHA-256: 36f3b7645609ef40444dbc68f01d26c543d67689eda4937272ea5cfa4df1b522
Table 14 contains known binaries and scripts from the threat actor’s repository of CNE tooling. The threat actors used these utilities to perform various scanning or computer intrusion tasks.
MD5: dae8f50ea44225fae3ba1f160b42bfdc
SHA-256: 670fa10a2ddde21fd594c4fef86b554d864089ed2de7153b472e921c623403ae
MD5: fdece34bc084f1e252aeae274650eb8d
SHA-256: 645f6f2667af01a94d04a9d7a71916a13d9426835d636b4ceee2e25ccb34e525
MD5: 596b990b0b389d906a8f4384837c1878
SHA-256: 4d488f21269b18e37aaca93ac2a61707c9b611e506cdb3b287277746e94636b5
MD5: a73eca669fe80628dbbd2c7d9bb14c8f
SHA-256: a14844e982f172d0f23910558c3f390a9d4c45dc32db825c2af7cf0ed8631db2
MD5: be121e707f817aa9392c55af1e7ec2aa
SHA-256: add7dd142e4f7e2873bc8f7b7fb6308063608e0b49a773dea93abad4047f1489
MD5: 7ce68f0dd85355ba2897a68521167e56
SHA-256: e7e727458f573dded05537baddac2867d2801db1c3c74410398d063dfd6f6575
MD5: f82694de2f19e1bff333c27bb7eb7a56
SHA-256: 8e1b56ef51ba70aa4c4cfd4430820f20875b354588d5d723ba4d3940ea6c924b
MD5: 1933c314041415939331fce183939547
SHA-256: 46e59172c40c95d83c3a6f24f801fc2265653c8b575b66a726463e2a4eebd7f2
MD5: 8829f6f1cc5fc0aab2f6e71bfd7dc53d
SHA-256: 752b14c6e6936991d51fcd5ebf40d303e657c2372893604f96044848ad9a5f24
MD5: cf903e4a1629aa0582fd0363b5786676
SHA-256: 7b9efc7ef8957411cdd22582ce4bfb3a5f76d9c91cdb7e36bf85c9785a2480e9
MD5: f01a9a2d1e31332ed36c1a4d2839f412
SHA-256: c9d5dc956841e000bfd8762e2f0b48b66c79b79500e894b4efa7fb9ba17e4e9e
MD5: ef713447f18f5b7ee16af4ac37ec4133
SHA-256: 2fbcb1995c458e5affd5fb8f1f979a08ddce21714a2e413aa3d5dc44f9f245fe
MD5: 8dcc4f9ccc6b6adf7eeeb3f51c95afad
SHA-256: 33790218d5871af646feef5be29e0596d4703a45ce675c1eb2ca00140b3a1bde
MD5: b04375cca637f0702bf27feaff22a92d
SHA-256: c7f86a4623db5c90273cea041d43207849c5c6b0060c370b2095f13871b1366d
MD5: bcacc7ca999980d26c186ef791242fb5
SHA-256: 2ecb51d7fa3bc3fa7ad7df64c6d0cd1f4ff2b37ed6839d3cff529fb08af49fb0
MD5: 1b8e29b6b7972fb124425aaa257f8f6d
SHA-256: efb0437e6a6a0f07169952f1a8b734299ec9a8b1faadbed811fe017f2cf54976
Table 15 contains known files that the threat actors dropped onto victim systems and used to install unauthorized software, dump sensitive information, or enable other follow-on activity from within a victim’s network.
MD5: 4f61b9ab907f351bb40b37b10f4974d0
SHA-256: 8b869a5edaff74ff18bca3658a519a19771e66d00ff7849af7a142dd6fc8da85
MD5: 6d57c42dee8bd7789969e2dd28671162
SHA-256: 804a53be802378a8ec4c94602fd3d6584e0d472d83148e8a42c731950fec415d
MD5: 776807750280daad05348f931a33e4ef
SHA-256: c4503db6ece93eddf4511e787607cb14606a1df9f526f1e39992497119437cec
MD5: a973c0ab904c1b74655a906b99b76850
SHA-256: b1552703ff0035f197c22cdb3a514bb6aa45ec98de3ef5409faab0978f18c35e
MD5: f62cbbbdf35c7790909c26c7c5fbce05
SHA-256: 8a592e22c51311d482272ec5aba0103c9cd0cfd78e5b5ba75dfa8f1c56926672
MD5: a05cdf6afcbb107961307f59cbab5e4f
SHA-256: 86f1cfa6a2e0a8cb6fc1fbee28472308e6467932f8658a6a4885e29ed8c34a67
MD5: 7d5a182f70bed0e4fa2f8615aba070de
SHA-256: e93244080a749b521f63476343ce3c81cc8c1b672fa0d9e67359aee37544c784
MD5: 1bcaef76b2063f1b80b0fa0d277ec9c5
SHA-256: 9dc85f9569a15eaf51c7d34254767ea30dd67b2178cec4cc7125288b9544fe00
MD5: 4d33bfb75e27fefaa72526899604d557
SHA-256: 644decbc6ce8c52382f4755fa6fc2cb4d89a0e7ec0e574c11b398a6f2eed04b1
MD5: fc6e8ca41cf4f6100177352660e520b4
SHA-256: 67db57a1f957031b78f29aa91e2e87780eae3835290259eff846d8f14afb794b
Appendix B: Observed Common Vulnerabilities and Exposures
Table 16 displays successfully exploited common vulnerabilities and exposures (CVEs). The asterisk (*) indicates CVEs that were newly added to CISA’s Known Exploited Vulnerabilities (KEV) Catalog .
CVE-2014-6278 [ Common Weakness Enumeration (CWE)-78: Improper Neutralization of Special Elements used in an OS Command (‘OS Command Injection’ )]
Through 4.3 bash43-026
Remote code execution
CVE-2015-3306 * [ CWE-284: Improper Access Control ]
CVE-2015-5477 * [ CWE-19: Data Processing Errors ]
Before 9.9.7-P2 and 9.10.x before 9.10.2-P3
CVE-2016-3081 * [ CWE-77: Improper Neutralization of Special Elements used in a Command (‘Command Injection’) ]
2.3.19 to 2.3.20.2, 2.3.21 to 2.3.24.1, and 2.3.25 to 2.3.28
Remote code execution
CVE-2019-11510 [ CWE-22: Improper Limitation of a Pathname to a Restricted Directory (‘Path Traversal’) ]
8.2 before 8.2R12.1, 8.3 before 8.3R7.1, and 9.0 before 9.0R3.4
CVE-2021-22205 [ CWE-94: Improper Control of Generation of Code (‘Code Injection’) ]
All versions starting from 11.9
Remote code execution
CVE-2021-3199 * [ CWE-22: Improper Limitation of a Pathname to a Restricted Directory (‘Path Traversal’) ]
CVE-2023-22894 * [ CWE-312: Cleartext Storage of Sensitive Information ]
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