Japanese company ITOCHU Cyber & Intelligence has identified an updated version of the LODEINFO backdoor, a tool associated with the Chinese nation-state actor Stone Panda. The malware, distributed through spear-phishing attacks, has been enhanced with new features and anti-analysis techniques. LODEINFO, first documented by Kaspersky in November 2022, is capable of executing arbitrary shellcode, taking screenshots, and exfiltrating files to a server controlled by the actor. Recent observations show changes in infection paths, including the use of remote template injection methods and the introduction of an intermediate stage in the attack delivery process.
The LODEINFO backdoor is attributed to Stone Panda, also known as APT10, Bronze Riverside, Cicada, Earth Tengshe, MirrorFace, and Potassium. This threat actor has a history of targeting Japan since 2021. The attack begins with phishing emails containing malicious Microsoft Word documents. Upon opening, VBA macros execute downloader shellcode, ultimately leading to the deployment of the LODEINFO implant. Notable changes include the addition of an intermediate stage involving a shellcode downloader fetching a file masquerading as a Privacy-Enhanced Mail (PEM) from a C2 server, loading the backdoor directly into memory.
Additionally, the LODEINFO version 0.7.1 includes checks for Microsoft Office language settings, indicating a preference for Japanese environments, though later removed in version 0.7.1 attacks. Changes in the filename language from Japanese to English suggest that version 0.7.1 was likely used to target environments in languages other than Japanese. The latest observed version is 0.7.3, highlighting the backdoor’s fileless nature and the need for memory-scanning malware detection to effectively counter its deployment.
