Malware developers write their software for a specific purpose, but gaining remote control of a user's device is the ultimate benefit for an attacker who wants to steal data or take over a user's computer. A Remote Access Trojan (RAT) is a tool that malware developers use to gain full access and remote control of a user's system, including their keyboard and mouse, access to their files, and their network resources. Instead of destroying files or stealing data, a RAT gives attackers full control of a desktop or mobile device so they can sneakily explore apps and files; and bypass normal security measures such as firewalls, intrusion detection systems, and authentication controls.
What are remote access trojans used for hackers?
A 2015 incident in the Ukraine illustrates how widespread RAT programs are, and how nefarious they can be. A group of attackers, using remote control malware, shut down power to 80,000 people by remotely accessing a computer with authenticated access to a SCADA (supervisory control and data acquisition) program on the computers that controlled the city's utility infrastructure. country. The RAT software made it possible for attackers to access sensitive resources by circumventing the elevated privileges of an authenticated user on the network. Gaining access to critical machinery that controls the city's resources and infrastructure is one of the biggest dangers of RAT malware.
There are legitimate remote control software, which allows an administrator to control a device remotely. For example, administrators use Remote Desktop Protocols (RDP) configured on a Windows server to remotely manage a system physically located in another location, such as a data center. Physical access to the data center is not available to administrators, so RDP gives them access to configure the server and manage it for increased corporate productivity.
RATs have the same remote control functionality as RDPs, but are used for malicious purposes. Attackers always program software to avoid detection, but attackers using a RAT risk being caught when the user is in front of the device and the mouse moves across the screen. Therefore, RAT programmers must create a hidden program and use it when the user is not in front of the device. To avoid detection, the author of a RAT hides the program in Task Manager, the Windows tool that lists programs and processes running in memory. Attackers try to avoid detection because it gives them more time to mine data and explore network resources for key components that they can use in subsequent attacks.
In addition to accessing network resources and files, any local hardware installed on the device is accessible to the attacker. An attacker using RAT software can access attached cameras, microphones, and USB devices, and an attacker can exploit these hardware resources to their advantage. For example, an attacker can use the camera to take photos of the user or their surroundings. These photos can be used to discover more about the target user or organization. They can also be used to blackmail the targeted user into sending the attacker a payment.
Launching Distributed Denial of Service (DDoS) attacks is another use for RATs. By controlling potentially thousands of devices, an attacker can command the devices to flood a targeted server with requests. What makes these attacks hard to prevent is that there are no warning signs of an attack, and the flood of traffic comes from hundreds or thousands of devices around the world. Users with devices controlled by a RAT are unaware of installed malware and are unaware that their devices are being used for malicious purposes. Network performance is often affected when a user's device is used for DDoS, but users are often unaware that performance degradation is a red flag of potential malware infection.
As Bitcoin and cryptocurrencies in general become more popular, attackers use RATs to configure infected devices to mine digital currencies. Digital currencies require great computing power to perform calculations. The cost of the electricity consumed by the computer arrays is usually higher than the price of the cryptocurrencies obtained. By hijacking computing power from outside parties, attackers can generate cryptocurrency without having to pay a dime for electricity.
Lastly, using a remote device to store files is a common technique for attackers who want to host illegal content. Instead of storing content on their own cloud-based servers and devices, attackers use stolen devices to avoid having accounts and servers shut down for illegal content.
How does a remote access trojan work?
To discover how RATs work, users can remotely access a device at home or on a work network. RATs work exactly like remote control software, but a RAT is programmed to remain hidden to avoid detection, either by anti-malware software or the device owner.
RATs often include other malware to help attackers achieve their goals. For example, it is not uncommon for a RAT program to include a keylogger. A keylogger runs stealthily in the background, recording the user's keystrokes. With a keylogger, an attacker can obtain credentials for a user's personal accounts or for business productivity tools. With the right credentials, an attacker can obtain financial data, intellectual property, or elevate your network privileges to remotely control other devices on a corporate network.
An attacker must convince the user to install a RAT, either by downloading malicious software from the Internet or by launching executable programs from a malicious email attachment or message. RATs can also be installed using macros in Microsoft Word or Excel documents. When a user allows the macro to run on a device, the macro stealthily downloads the RAT software and installs it. With the RAT installed, an attacker can remotely control the desktop, including mouse movements, clicks, camera controls, keyboard actions, and any configured peripherals.
As an attacker accesses the computer remotely, authenticated accounts (such as email) are at risk. Attackers can use email, for example, to send malicious messages to other potential victims using the authenticated email account on the remotely controlled device. Using a trusted email account gives attackers a better chance of tricking an email recipient into installing malware or executing a malicious attachment.
