A RAT (Remote Access Trojan) is a type of malicious software that allows cybercriminals to secretly control an infected computer or device over the internet. Once installed, a RAT gives attackers remote access to files, cameras, microphones, and system settings, often without the victim’s knowledge. This enables them to steal sensitive data, monitor user activity, install additional malware, or use the device for other criminal purposes. RATs are typically spread through phishing emails, malicious downloads, or infected attachments, and are designed to operate stealthily to avoid detection by security software.