The TIDRONE espionage group, a previously undocumented cyber threat actor, has surfaced in 2024 with a focused campaign targeting drone manufacturers in Taiwan. Trend Micro researchers have identified this group, which is likely linked to Chinese-speaking entities, as carrying out espionage-driven attacks aimed at compromising military-related industry chains. The campaign appears to prioritize gathering sensitive information from drone makers, with a particular focus on organizations involved in Taiwan’s defense sector. This activity aligns with broader Chinese cyber-espionage interests, although the exact motivations behind the attacks remain under investigation.
The attack vector used by TIDRONE to initially breach targets is currently unknown. However, Trend Micro’s analysis has identified a consistent deployment of custom malware—CXCLNT and CLNTEND—along with the use of remote desktop tools like UltraVNC. One notable observation across multiple victims is the presence of the same enterprise resource planning (ERP) software, hinting at the possibility of a supply chain attack. The attackers may have exploited vulnerabilities in this shared software to gain access to their targets’ systems, though this theory is yet to be confirmed.
Once inside the targeted systems, TIDRONE’s attack unfolds in three stages designed to escalate privileges, extract sensitive information, and evade detection. The group leverages a User Access Control (UAC) bypass for privilege escalation, along with credential dumping techniques to access further data. To ensure persistence and stealth, the attackers disable antivirus software installed on the infected machines. The backdoors, CXCLNT and CLNTEND, are delivered through a rogue DLL sideloaded via Microsoft Word, which provides the threat actors with a foothold to steal a wide range of sensitive information, including file listings and computer names.
CXCLNT, a key tool in this operation, has basic functionality such as uploading and downloading files, clearing traces, and collecting victim information. CLNTEND, first detected in April 2024, acts as a more advanced remote access tool (RAT) supporting multiple network protocols, including TCP, HTTP, HTTPS, TLS, and SMB. The consistency in file compilation times and the operation patterns of the threat actor suggest that this campaign is part of a broader espionage effort by a Chinese-speaking group, though their specific identity remains undetermined. Security researchers continue to track the group’s activities as they unfold.
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