SOCRadar® Cyber Intelligence Inc. | Dark Web Profile: APT31


May 09, 2024
9 Mins Read

Dark Web Profile: APT31

Advanced Persistent Threat Group 31 (APT31), also known by aliases like ZIRCONIUM or Judgment Panda, represents a sophisticated cybersecurity threat with ties to state-sponsored activities.

Threat Actor Card of APT31

Threat Actor Card of APT31

This group is believed to operate primarily on behalf of the Chinese government, engaging in cyber espionage and targeted attacks to gather intelligence and support strategic objectives aligned with China’s national interests.

APT31 Depiction, Image created by BING AI

APT31 Depiction, Image created by BING AI

APT31’s activities are characterized by advanced tactics, including the use of malwarespear-phishing campaigns, and exploitation of zero-day vulnerabilities, making them a significant concern for global cybersecurity efforts. Understanding APT31’s modus operandi and the implications of its actions is crucial in combating cyber threats posed by state-sponsored actors.

Indictment and Charges

In recent developments, the United States Department of Justice unsealed an indictment charging seven individuals associated with APT31, a Chinese state-sponsored hacking group, with conspiracy to commit computer intrusions and wire fraud. The indictment, announced on March 25, 2024, sheds light on APT31’s extensive cyber operations targeting perceived critics of China, U.S. businesses, and political officials over a span of approximately 14 years.

The defendants, identified as Ni Gaobin, Weng Ming, Cheng Feng, Peng Yaowen, Sun Xiaohui, Xiong Wang, and Zhao Guangzong, are believed to reside in China and have allegedly operated as part of the APT31 hacking group in support of China’s Ministry of State Security’s objectives related to transnational repression, economic espionage, and foreign intelligence.

The U.S. Department of State’s Rewards for Justice (RFJ) program, individuals associated with APT31 (rewardsforjustice)

The U.S. Department of State’s Rewards for Justice (RFJ) program, individuals associated with APT31 (rewardsforjustice)

The indictment outlines APT31’s tactics, including the use of more than 10,000 malicious emails to target individuals worldwide. These emails, often disguised as legitimate news articles from prominent sources, contained hidden tracking links that transmitted sensitive information about the recipients back to the hackers. APT31 then used this information to conduct more sophisticated targeted attacks, compromising victims’ networks, email accounts, cloud storage, and telephone call records.

The indictment also highlights APT31’s targeting of U.S. government officials, political figures, election campaign staff, and U.S. companies across various industries. The group’s activities included attempts to gather economic plans, intellectual property, and trade secrets, contributing to significant financial losses for American businesses.

Moreover, APT31 targeted dissidents and individuals supporting dissident causes globally, including surveillance and intrusions into the networks of activists and organizations critical of the Chinese government.

For further details about the indictment and charges you may refer to court’s statement.

APT31 Techniques and Modus Operandi

According to the indictment APT31 has ties to the Hubei State Security Department in Wuhan. Around 2010, APT31 established a front company named “Wuhan XRZ” to conceal its cyber operations, leveraging another local entity called “Wuhan Liuhe” for support, although the latter was not directly implicated as an MSS front.

Associated Malware with APT31

Associated Malware with APT31

APT31 was observed employing a dual-phase approach, initiating emails purportedly from prominent US journalists sent to potential victims. These emails included snippets from genuine news articles along with tracking links, presumably leading to the full article. Clicking these links provided attackers with initial data, such as the device type used to open the email and the recipient’s public IP address. Notably, between June and September 2018 alone, over 10,000 tracking emails were dispatched.

Subsequently, armed with this gleaned information (T1598.003), APT31 proceeded to launch direct hacking endeavors against the victims’ devices. The indictment specifically highlights APT31’s targeting of victims’ family members, allowing them to exploit less secure home routers rather than more fortified corporate networks. This strategic shift towards targeting Small Office/Home Office (SOHO) devices aligns with findings from ANSSI’s report in December 2021.

Initially, APT31 employed various malware families like RAWDOORTrochilusEvilOSXDropDoor/DropCat, employing DLL side-loading for staging. However, they later transitioned to utilizing cracked versions of Cobalt Strike, a legitimate software testing tool. A notable strategy of APT31 involves a two-pronged approach to hacking, targeting subsidiaries, managed service providers or even spouses of their primary targets to gain initial access.

An instance cited by the U.S. DoJ involves APT31 compromising a victim’s subsidiary, a defense contractor manufacturing military flight simulators, as a stepping stone to infiltrate the core network. This operation involved leveraging a local privilege escalation 0-day exploit followed by an SQL injection.

Related CVEs for APT31

Related CVEs for APT31

While APT31 leans towards server-side exploitation to minimize interactions with victims in these campaigns, the indictment reveals a broader spectrum of activities. For instance, their involvement in targeting Hong Kong’s Umbrella Movement activists in 2019 showcases reliance on spear phishing emails containing malicious attachments or links. Moreover, the defendants are accused of crafting counterfeit Adobe Flash update pages to deploy the EvilOSX malware (T1036).

Targeted countries by APT31

Targeted countries by APT31

A noteworthy detail in the indictment is APT31’s use of double infections for some victims, enabling them to re-access the network if the initial malware implant was detected, underscoring their sophisticated and persistent tactics.


APT31, a Chinese cyber-espionage group, has posed a persistent and evolving threat since its emergence. The tactics employed by APT31 are multifaceted and sophisticated. They encompass a wide range of techniques, from spear phishing emails and exploiting software vulnerabilities to custom-built malware. This adaptability and evolution in tactics render APT31 a highly dangerous threat actor.

The global scope and dynamic nature of APT31’s operations underscore the critical need for vigilance and robust cybersecurity measures. As APT31 continues to refine its tactics and strategies, organizations must also enhance their defenses to effectively counter these threats.

Security Recommendations Against APT31

Educate and Train Staff: Conduct regular training sessions to help staff recognize and mitigate phishing attempts and malicious attachments, especially spear-phishing emails.

Keep Software Updated: Ensure all software is regularly updated to patch known vulnerabilities, reducing potential avenues for unauthorized access by APT31.

Implement Multi-Factor Authentication (MFA): Utilize MFA, particularly for critical systems and data, to add an extra layer of security even if passwords are compromised.

Monitor for Suspicious Activity: Regularly monitor networks and systems for any unusual or suspicious activity that may indicate a breach or intrusion.

Use Security Software: Employ robust security software capable of detecting and blocking malware and other malicious activities associated with APT31.

Collaborate and Share Information: Foster collaboration with other organizations and government agencies to share threat intelligence and best practices for defense against APT31.

Develop an Incident Response Plan: Establish a comprehensive incident response plan to swiftly and effectively respond to security incidents, including breaches attributed to APT31.

By implementing these proactive measures, organizations can significantly reduce their risk of falling victim to APT31 and other cyber-espionage groups. Cyber Threat Intelligence plays a crucial role in staying ahead of specific threats like APT31 by identifying vulnerabilities and enabling preemptive actions to mitigate potential risks.


MITRE ATT&CK Techniques

Below are the techniques used by ZIRCONIUM or APT31 in MITRE.

ID Name Use
T1583.001 Acquire Infrastructure: Domains ZIRCONIUM purchased domains for targeted campaigns.
T1583.006 Acquire Infrastructure: Web Services ZIRCONIUM used GitHub to host malware linked in spearphishing emails.
T1547.001 Boot or Logon Autostart Execution ZIRCONIUM created a Registry Run key for persistence with a malicious binary.
T1059.003 Command and Scripting Interpreter: Cmd ZIRCONIUM opened a Windows Command Shell on a remote host.
T1059.006 Command and Scripting Interpreter: Python ZIRCONIUM used Python-based implants for interaction with compromised hosts.
T1555.003 Credentials from Password Stores ZIRCONIUM stole credentials from web browsers.
T1140 Deobfuscate/Decode Files or Information ZIRCONIUM used AES256 decryption for exploit code.
T1573.001 Encrypted Channel: Symmetric Cryptography ZIRCONIUM utilized AES encrypted communications in C2.
T1041 Exfiltration Over C2 Channel ZIRCONIUM exfiltrated files via the Dropbox API C2.
T1567.002 Exfiltration Over Web Service ZIRCONIUM exfiltrated data to Dropbox.
T1068 Exploitation for Privilege Escalation ZIRCONIUM exploited CVE-2017-0005 for local escalation.
T1105 Ingress Tool Transfer ZIRCONIUM downloaded malicious files to compromised hosts.
T1036.004 Masquerading: Masquerade Task or Service ZIRCONIUM used a run key for masking a persistence mechanism.
T1027.002 Obfuscated Files or Information: Packing ZIRCONIUM used multi-stage packers for exploit code.
T1566.002 Phishing: Spearphishing Link ZIRCONIUM used malicious links in emails for malware delivery.
T1598.003 Phishing for Information ZIRCONIUM targeted presidential campaign staffers with credential phishing emails.
T1012 Query Registry ZIRCONIUM queried the Registry for proxy settings.
T1218.007 System Binary Proxy Execution: Msiexec ZIRCONIUM used msiexec.exe for downloading and executing malicious MSI files.
T1082 System Information Discovery ZIRCONIUM captured processor architecture for C2 registration.
T1016 System Network Configuration Discovery ZIRCONIUM enumerated proxy settings.
T1033 System Owner/User Discovery ZIRCONIUM captured usernames for C2 registration.
T1124 System Time Discovery ZIRCONIUM captured system time for C2 registration.
T1204.001 User Execution: Malicious Link ZIRCONIUM used malicious links for malware downloads.
T1102.002 Web Service: Bidirectional Communication ZIRCONIUM used Dropbox for bidirectional C2 communication and execution of commands.

Latest IoCs for APT31

Below are the latest IoCs for APT31 in SOCRadar Platform

SHA-256 Hashes:












For more detailed information about Chinese and Russian threat actors and their threat landscape, please see our relevant report.