What is a Remote Access Trojan (RAT)?

A Remote Access Trojan, or RAT, is malware that gives an attacker control over an infected computer from anywhere in the world.

Once installed, it runs quietly in the background, letting the attacker see what's on your screen, access your files, turn on your webcam or microphone, log your keystrokes, and essentially do anything you could do sitting at the keyboard.

The "trojan" part of the name comes from the Greek myth—these programs sneak onto systems disguised as legitimate software, or they slip in through security holes without the user knowing anything happened. Unlike viruses that spread themselves or ransomware that announces its presence, RATs are designed for stealth.

An attacker might maintain access for months, watching and waiting, stealing data bit by bit, or using the compromised machine as a launching point for attacks deeper into a network. They're a favorite tool of both sophisticated state-sponsored hackers and cybercriminals, since they offer such complete control with relatively low risk of detection if deployed carefully.

Remote Access Trojans emerged in the late 1990s as internet connectivity became common in homes and businesses. Early examples like Back Orifice (released in 1998) and NetBus started as hacker tools that demonstrated how vulnerable Windows systems were to remote control. Back Orifice was particularly notorious—released at the DEFCON hacker conference, it could completely compromise Windows 95 and 98 systems, and while its creators claimed it was meant to expose Microsoft's security failures, it quickly became a blueprint for malicious actors.

Through the 2000s, RATs evolved from crude proof-of-concept tools into sophisticated malware. SubSeven, Poison Ivy, and DarkComet became staples of cybercrime, offering increasingly user-friendly interfaces that let even non-technical criminals deploy them.

By the 2010s, state-sponsored groups were using custom RATs for espionage—tools like Gh0st RAT and PlugX appeared in campaigns attributed to nation-state actors. The commercialization of RATs as "remote administration tools" created a gray market where the same software could be legitimately used by IT departments or illegitimately deployed by attackers.

RATs remain one of the most dangerous categories of malware because they give attackers time and flexibility. Unlike ransomware that needs to act quickly, a well-hidden RAT can sit on a network for months or years, a problem so common that the average time between initial compromise and detection is measured in weeks or months. For businesses, this means intellectual property theft, credential harvesting, and reconnaissance that enables more damaging attacks. Attackers often use RATs to map out networks, figure out where valuable data lives, steal credentials with elevated privileges, and prepare for ransomware deployment or data exfiltration.

The tools themselves have become easier to use—some are sold as malware-as-a-service, requiring no technical expertise to deploy. Detection is challenging because modern RATs use encryption, hide in legitimate system processes, and communicate with command-and-control servers in ways that mimic normal internet traffic.

For individuals, RATs enable identity theft, financial fraud, and disturbing privacy violations including webcam and microphone surveillance. The shift to remote work has expanded the attack surface, as home networks and personal devices often lack the security controls of corporate environments.

Plurilock's approach to RAT detection and prevention combines multiple layers of defense. Our penetration testing services identify the vulnerabilities that RATs typically exploit for initial access, while our managed detection and response capabilities monitor for the subtle behavioral indicators that reveal hidden RAT activity—unusual network connections, persistence mechanisms, and privilege escalation attempts.

We help organizations implement zero-trust architectures that limit the damage even if a RAT gains a foothold, and our incident response team has deep experience extracting attackers from compromised environments and hardening systems against reinfection.

When it comes to RATs, speed matters—we mobilize in days, not weeks.