What is a Remote Access Trojan (RAT)?

Trojan attacks are some of the most nefarious cybersecurity threats, and remote access Trojans (RATs) that give hackers total control over your device are especially dangerous. But knowing how a remote access Trojan works — and how to detect one — can help protect you from an attack.

What is a Remote Access Trojan (RAT)?

A Remote Access Trojan (RAT) is malware an attacker uses to gain full administrative privileges and remote control of a target computer. RATs are often downloaded along with seemingly legitimate user-requested programs – such as video games – or are sent to their target as an email attachment via a phishing email.

Once the host system is compromised, intruders use a backdoor to control the host, or they may distribute RATs to other vulnerable computers and establish a botnet.

Belonging to the family of Trojan horse viruses, RATs are specifically designed to disguise themselves as legitimate content.

How does it work?

Remote access trojan malware works just like non-malicious remote access tools. The difference is that RATs are designed to stay hidden and carry out tasks without the device owner’s consent or knowledge.

To install a RAT on a machine, the hacker must first fool the owner into downloading the software. The bad actor might send an email attachment or a link to a seemingly legitimate website where the user can download the software.

The downloaded application imitates a trustworthy remote access app, but once installed, it does not show up on any list of active software or running processes. This means a RAT may reside inside a poorly protected computer or server for a long time without detection.

Remote access trojans are particularly dangerous because they give the hacker complete administrative control. As a result, attackers can use the infected machine or network as a proxy server to commit crimes anonymously. RATs are sometimes paired with a keylogger to increase the hacker’s chances of obtaining sensitive information or login details. Because the hacker has access to the unsuspecting user’s camera and microphone, the victim’s privacy is also completely compromised.

Why are Remote Access Trojans Dangerous?

Cybersecurity teams often have difficulty detecting RATs because they generally don’t appear in running tasks or program lists. RATs commonly perform actions similar to those of valid programs. Also, an attacker will manage the level of resource use so that there is no drop in performance, making it more difficult to notice the threat.

Here are several ways a Remote access trojan attack can endanger individual users, organizations, or even entire populations:

• Spying and blackmail – an attacker who deploys RAT on a user’s device gains access to its cameras and microphones. They can take photos of the user and their environment, and use them to conduct more sophisticated attacks or to blackmail the user.
• Launching distributed denial of service (DDoS) attacks – when attackers have RATs deployed on a large number of user devices, they can use these devices to flood a target server with fake traffic. Users are commonly unaware that their devices are used for DDoS, although an attack can result in network performance degradation.
• Cryptomining – attackers can use a RAT to mine Bitcoin or other cryptocurrency on a user’s computer. By scaling their operation across a large number of devices, they can generate significant earnings.
• Remote file storage – attackers can leverage RAT to store illegitimate content on the devices of unsuspecting victims. This way, authorities cannot shut down the attacker’s account or storage server, because their data is stored on devices belonging to legitimate users.
• Compromising industrial systems – attackers can use RAT to take control of large-scale industrial systems, including public utilities like water and electricity. The attacker can sabotage these systems, causing widespread damage to industrial machinery, and potentially disrupting critical services to entire areas.

How to protect yourself from Remote Access trojans?

Remote access trojans (RATs) operate silently and often invisibly, so you must take security measures to prevent malware from entering your device and spreading further. Here are some safety measures you can take:

• Keep your software updated. Ensure your software is up to date to avoid hackers exploiting software vulnerabilities and infecting your devices.
• Use an antivirus program and other cybersecurity tools. Update your antivirus and firewall system regularly and run system scans from time to time. This way, you will detect unwanted and harmful viruses in time before they do irreversible damage.
• Beware of phishing emails. Phishing emails are one of the primary methods attackers use to distribute RATs. They send out emails often containing malicious attachments or links to infected web pages, opening the back door for the malware. Be wary of suspicious emails from unknown senders.
• Use a VPN. VPN services encrypt your browsing traffic and can help protect your online activities from being monitored or intercepted by attackers.
• Pay attention to your system’s behavior. Remote access trojans often enter devices without the user noticing, so keep an eye out for suspicious activity. If you see any unusual activity or unexpected changes on your system, there is a chance that your computer has been infected with malware.
• Get an attachment filter. An additional security solution is designed to protect you from downloading malware onto your device. It’s a security feature that keeps you safe when browsing and protects you from malware. This tool scans your downloads and blocks malicious content before it infects your device.
• Use multi-factor authentication. This is an additional security solution that requires more than one authentication method. Besides a password, the system requires authentication of different categories, such as a fingerprint, security token, or SMS code. The idea is that multi-factor authentication makes it more difficult for an attacker to get into a system.
• Use intrusion detection systems. A type of security software designed to detect unauthorized access or malicious activity on a device or system. Intrusion detection systems monitor network traffic, logs, and system activities and indicate an intrusion or attack.

Final thoughts

Cyber threats are always on the rise, and the threat posed by remote access trojans is significant. Understanding what they are, how they work, and why they are dangerous is the first step towards protection. Implementing protective measures and maintaining vigilance in digital activities can go a long way in safeguarding valuable information and systems from the devastating effects of a RAT attack.