A previously unknown threat actor with possible ties to Chinese-speaking groups has primarily targeted drone makers in Taiwan as part of a cyber attack operation that started in 2024. Trend Micro is tracking the adversary under the codename TIDRONE, claiming that the activity is espionage-driven due to the emphasis on military-related company chains.
The specific initial access vector used to penetrate targets is currently unknown, although Trend Micro's study revealed the spread of unique malware such as CXCLNT and CLNTEND using remote desktop tools such as UltraVNC. An interesting feature identified across multiple victims is the use of the same enterprise resource planning (ERP) software, increasing the likelihood of a supply chain attack.
After that, the attack chains move through three distinct phases that are intended to make it easier to escalate privileges through the use of credential dumping, security evasion by turning off antivirus software that is installed on the hosts, and User Account Control (UAC) bypass.
Both backdoors are activated by sideloading a rogue DLL using the Microsoft Word application, allowing attackers to collect a wide range of confidential data. CXCLNT includes basic upload and download file capabilities, as well as facilities for removing traces, acquiring victim data such as file listings and device names, and downloading next-stage portable executable (PE) and DLL files for execution.
CLNTEND, detected in April 2024, is a remote access tool (RAT) that supports a broader range of network communication protocols, including TCP, HTTP, HTTPS, TLS, and SMB (port 445).
"The consistency in file compilation times and the threat actor's operation time with other Chinese espionage-related activities supports the assessment that this campaign is likely being carried out by an as-yet unidentified Chinese-speaking threat group," security researchers Pierre Lee and Vickie Su stated.