Has a technician has likely accessed your machine from a remote location. This remote access is a hacker’s dream and can be done using Remote Access Trojan (RAT). 

They can take control of the PC using software created for this specific function. 

From downloading software, opening documents, moving the cursor around the screen in real-time, being able to collect information from anyone without their knowledge. 

Here we will explain what a remote access Trojan is, how it works, and how we can avoid it.

What is a Remote Access Trojan and How it Works, Exactly?

A remote access Trojan, more popularly known as RAT, is a type of malware that can carry out covert surveillance on a victim’s computer. 

Its behavior is very similar to that of keyloggers. However, RATs can do much more than collect data on keystrokes, usernames, and passwords. 

You can gain remote access to the victim’s computer through specially configured communication protocols that allow malware to go unnoticed. 

Backdoor access provides virtually complete access to the machine, allows you to change settings, control user behavior, use the computer’s Internet connection, and even access other computers on the victim’s network. 

A hacker with a RAT can erase your hard drive, download illegal content from the Internet through your computer, or introduce additional malware onto it. 

Hackers can also control your computer remotely to perform illegal actions online on your behalf or use your home network as a proxy server to commit crimes anonymously. 

A hacker can also use a Trojan to take control of a home network and create a botnet. 

Essentially, a botnet allows a hacker to use a computer’s resources for tasks like DDOS attacks, Bitcoin mining, file hosting, and torrenting. 

Like most malicious programs, RATs are supplemented with files that appear legal.

 Hackers include a Trojan inside a document in an email or inside a large software package, such as a video game. Ads and unsafe web pages can also contain Trojans. 

Knowing when we have downloaded a Trojan is quite difficult, unlike other types of malware. 

This will not affect the functioning of the computer, and hackers will not always give themselves away by deleting your files or moving the cursor around the screen. In some cases, it can take years for infected users to notice anything.

5 Types of RATs (Remote Access Trojans)

There are several remote access systems that may have legitimate applications, but they are known as tools that hackers use primarily as part of a Trojan; these are classified as remote access Trojans. 

The main ones are the following:

  1. Back Orifice – Also known as BO, this is the granddaddy of RATs and has been refined and adapted by other hacker groups to produce newer RAT systems. The original system exploited a weakness in Windows 98. Later versions that ran on the newer Windows operating systems were Back Orifice 2000 and Deep Back Orifice.

  2. Bifrost – This Trojan begins its infection with the installation of a server generator program. Initially, this program only contacts a Command and Control server and waits for instructions. Once activated, the server builder will configure a server program on the target computer.

  3. Blackshades -The toolkit is very easy to use and allows those who lack technical skills to become hackers. It includes infection methods, such as malicious code to embed in websites that trigger installation routines. Other elements spread the RAT by sending links to infected web pages. These are sent to the social network contacts of an infected user.

  4. DarkComet – The software allows spying by keylogging, screen capture, and password collection. The controlling hacker can also operate the power functions of a remote computer, allowing it to be turned on or off remotely.

  5. Mirage – It is the key RAT used by the Chinese state-sponsored hacking group known as APT15. They access the target systems through spear-phishing campaigns. These are generally aimed at the executives of a victim company.

    The Trojan is delivered embedded in a PDF. When you open the PDF, the scripts run and install the Trojan.

Antivirus systems don’t work very well against Trojans. 

Sometimes a computer or network infection goes undetected for years. 

The obfuscation methods used by parallel programs to hide RAT procedures make them very difficult to detect.

How to Avoid RATs (Remote Access Trojans) At All Cost

Sometimes the only solution to remove a Trojan from your computer is to remove all software and reinstall the operating system. 

RAT prevention systems are rare because Trojan software can only be identified once it is running on the system. 

The best way to handle the problem is to use an intrusion detection system.

Next, we will show the main tools to detect Trojan software.

RAT Detection Tool #1 – OSSEC (Open Source HIDS Security): Is the current leader in HIDS and can be installed on Unix, Linux, and Mac OS operating systems. Examine the event logs for RAT activities. This software is an open-source project owned by the cybersecurity company, Trend Micro.

RAT Detection Tool #2 – Bro: This is a free NIDS that can be installed on Unix, Linux, and Mac OS. It is highly analytical because it applies cross-packet analysis and uses signature-based analysis and anomaly-based detection.

RAT Detection Tool #3 – Suricata: This is a rate-based system that applies application layer analysis, so it will detect the signatures that are distributed between the packages. It monitors the activity of the IP, TLS, TCP, and UDP protocols and targets key network applications such as FTP, HTTP, ICMP, and SMB.

RAT Detection Tool #4 – Sagan: is a free host-based intrusion detection system that can be installed on Unix, Linux, and Mac OS. Sagan cannot run on Windows, but you can feed Windows event logs into it. It should be used in conjunction with other data collection systems to create a complete intrusion detection system.

RAT Detection Tool #5 – Security Onion: It was developed by joining the code for Snort, Suricata, OSSEC, and Bro, which are open source projects. Host-based scan checks for file changes and network scan is done by the packet sniffer, which can display pass data on a screen and also write to file.

RAT Detection Tool #6 – AIDE: It focuses on rootkit detection and file signature comparisons. The data collection module populates a database of characteristics obtained from the log files. System checks are performed on demand and not on a continuous basis, but can be scheduled as chronological jobs.

RAT Detection Tool #7 – OpenWIPS-NG: Runs on Linux. This is a free utility that includes three elements: Sensor (the packet sniffer), Server (data storage and analysis database, and Interface (front-end user-oriented).