RemoteAccessTrojaner

RemoteAccessTrojaner, commonly abbreviated as RAT, is a type of malicious software designed to provide remote access and control over an infected computer or device. The term is the German equivalent of Remote Access Trojan and is used in threat reports to describe a covert backdoor installed by an attacker. RATs are typically delivered through phishing emails, drive-by downloads, or software bundled with seemingly legitimate programs, and they often masquerade as a normal application to avoid suspicion. After execution, the RAT establishes a communication channel with a command-and-control server or a peer network, granting the attacker persistent access.

Capabilities of RATs include remote desktop and file system access, keystroke capture, screen and webcam capture, clipboard monitoring, process and service control, command execution, and data exfiltration. Some RATs can alter system settings, install additional components, or pivot within a network. Many are designed to stay hidden, using stealth techniques, minimal user interface footprints, masquerading processes, and persistence mechanisms such as registry keys, scheduled tasks, or services.

Operational models vary; most RATs use a client component on the infected host that communicates with a C2 infrastructure, sometimes over encrypted channels or using secure tunneling to evade detection. They may implement beaconing intervals, domain fallback, or fast-flux techniques. Delivery and propagation methods include phishing, malicious downloads, and software bundling, while persistence mechanisms help maintain access even after reboots.

Prevention and defense include keeping software patched, using endpoint protection and network monitoring for unusual outbound traffic, disabling unnecessary remote access services, applying least privilege, and user education to recognize phishing attempts. If detected, RAT infections are typically mitigated with malware removal tools, system restores or reimaging as needed, and a post-incident investigation for lateral movement. In contrast to legitimate remote administration tools, RATs operate covertly and without user consent, and are a common tool in cyber intrusions.