Pierluigi Paganini January 10, 2025

Japanese authorities attributed a cyber-espionage campaign targeting the country to the China-linked APT group MirrorFace.

The National Police Agency (NPA) and the Cabinet Cyber Security Center in Japan have linked a long-running cyber-espionage campaign targeting local entities to the China-linked group MirrorFace (aka Earth Kasha).

The campaign has been active since at least 2019, it targets Japanese technology and national security, evolving methods to steal advanced tech and intelligence.

MirrorFace was first spotted by ESET in 2022, targeting Japanese political entities ahead of elections.

The group exploited vulnerabilities in networking equipment, including CVE-2023-28461 (Array Networks), CVE-2023-27997 (Fortinet), and CVE-2023-3519 (Citrix).

Between 2019 and 2024, the MirrorFace group launched three cyber campaigns targeting Japanese think tanks, government, academia, and key industries.

• Campaign A (2019–2023): Used emails with malware attachments (LODEINFO) to target politicians, media, and government.
• Campaign B (2023): Exploited software vulnerabilities in networking devices, focusing on semiconductor, manufacturing, and aerospace sectors.
• Campaign C (2024): Delivered malware (ANEL) via email links, targeting academia and think tanks, evolving to abuse Visual Studio Code.

These campaigns highlight ongoing efforts to steal advanced technology and national security data.

“Analysis by the NPA Cyber Special Investigation Division, the Metropolitan Police Department, and prefectural police departments indicates that these campaigns are systematic cyberattacks linked to China, primarily aiming to steal information related to Japan’s national security and advanced technologies.” reads the report published by NPA. “This alert serves to publicize the attack methods employed by MirrorFace and raise awareness.”

In both campaigns A and C, attackers used spear-phishing attacks, however, the two campaigns show notable differences in their malware and infection techniques. Campaign A relied on LODEINFO, a type of malware that infected systems primarily through malicious email attachments. In contrast, Campaign C employed ANEL, with infections initiated via links embedded in the email body. Additionally, while earlier campaigns, including Campaign A, were marked by the abuse of Windows Sandbox, Campaign C showcased an evolution in tactics by also exploiting Visual Studio Code (VS Code) to compromise targeted systems.

The China-linked group used two evasion methods in its campaigns, Visual Studio Code (VSCode) tunnels and Windows Sandbox.

MirrorFace has been using Visual Studio Code (VSCode) tunnels since June 2024 to establish covert communication channels on compromised systems. These tunnels receive PowerShell command instructions. This tactic has also been observed with other China-linked APT groups.

Since June 2023, MirrorFace has used the Windows Sandbox feature to execute LOADEINFO malware within an isolated environment, evading antivirus detection. Windows Sandbox allows safe execution of commands, but since the host OS, including Microsoft Defender, does not monitor this virtualized environment, malware can run undetected, communicate with remote servers, and maintain access to the host via shared folders.

The alert issued by Japan NPA recommends System Administrators to:

• Implement centralized log management to track breaches, as logs are critical for identifying causes and scope. Use tools like SIEM or CISA’s “Logging Made Easy” for log aggregation.
• Regularly monitor network device logs for abnormal activities, like unauthorized logins or unusual VPN behavior.
• Ensure that administrative accounts are restricted, and monitor for any inactive accounts.
• Stay updated on network device vulnerabilities and apply patches promptly.

it also suggests to

• Disable unnecessary features like Windows Sandbox if not needed and monitor for unauthorized activities like the activation of development tools (e.g., VS Code).
• Track antivirus detections carefully. Even after malware is removed, continued monitoring is necessary to ensure no undetected threats remain.

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Pierluigi Paganini

(SecurityAffairs – hacking, MirrorFace)