A backdoor is a type of cybersecurity threat that allows attackers to secretly compromise a system and conduct malicious activities, such as stealing data and modifying files. Backdoors can be difficult to detect, as they often use legitimate system applications to evade defense mechanisms. Threat actors often utilize special malware, such as PlugX, to establish backdoors on target devices.

Remote access trojans (RATs) are a type of malware that enables attackers to establish complete to partial control over infected computers. Such malicious programs often have a modular design, offering a wide range of functionalities for conducting illicit activities on compromised systems. Some of the most common features of RATs include access to the users’ data, webcam, and keystrokes. This malware is often distributed through phishing emails and links.

ValleyRAT is a classic remote access trojan first documented in 2023, targeting mainly Windows systems. It is used by threat actors to gain persistent access to infected devices, steal data, and control compromised machines. ValleyRAT is notable for its relatively advanced evasion techniques and its connections to a prominent Chinese APT group.