With an increasing number of bad actors seeking to infect personal computers with malware, just going online can seem like a rather risky proposition these days. Malware is an ever-present threat, and one particularly nefarious type of malware is the remote access trojan (RAT).
As the name implies, a remote access trojan is a type of malware that gives the hacker remote access to your computer. In this guide, we’ll delve deeper into what a remote access trojan is, how it works, and how to remove one from your Mac or MacBook.
What is a remote access trojan, and how does it work?
Once embedded on your MacBook, a remote access trojan (also known as a RAT) will set up a secret backdoor, which a hacker can use to send commands to your device and receive data back.
The commands used by a RAT could include logging your keystrokes, transferring your files, or activating your webcam, among many others.
Why do hackers use RATs?
RATs are very popular among hackers due to their versatility and ability to give a cyberattacker complete control over your MacBook. Some of the benefits for attackers include:
- RATs can be very difficult to locate. They prioritize hiding in the depths of your machine.
- A RAT can give a hacker remote access to your computer, potentially from the other side of the world.
- RATs are extremely easy to use. A hacker needs no instruction manual, and there is no steep learning curve.
- RATs can be used to set up botnets, which are large groups of compromised computers that can be used to launch distributed denial of service (DDoS) attacks against websites.
Why are remote access trojan attacks considered dangerous?
Remote access trojan attacks are especially dangerous for the following reasons:
- It is often difficult to detect a RAT by using antivirus software.
- Once inside the computer, a RAT will quickly alter the system settings and begin setting up more malware.
- If RAT malware gets inside a network, it will quickly spread to other machines connected to that network.
- A RAT can manipulate elements of the computer, including the keyboard strokes and the webcam. This can lead to valuable and perhaps compromising data being stolen or the owner being forced to pay a ransom.
Сommon signs of a RAT trojan infection
The telltale signs of a RAT infection are no different than those associated with other forms of malware. Here are the RAT symptoms you need to look out for:
- Your system starts to slow down: Malware requires a lot of CPU power to operate in the background and is competing with your normally running apps. If your Mac or MacBook suddenly slows down, check the Activity Monitor to see which apps are hogging all the juice.
- You suddenly have unknown apps on your machine: Like any malware, a RAT needs to set up its own program to run malicious scripts, communicate with home base to receive commands, and transfer your data out. This means you’ll likely have unauthorized apps appearing on your Mac.
- Your internet usage increases: For the same reason as noted previously, your internet usage will go up as network traffic starts to heat up at all hours, day and night.
- Pop-ups and redirects: As part of its data-gathering operation, a RAT may use adware to place pop-up windows on your screen and redirect you to malicious websites.
- Your webcam is activated: One of the things a RAT can do when on your MacBook is activate your webcam. So, if you see the webcam blinking on and off, you have a problem.
- Your typing speed gets sluggish: When the RAT is logging your keystrokes, it can lead to your typing speed slowing down and your accuracy becoming rather dodgy.
How can you detect a remote access trojan?
If you’re experiencing the telltale signs outlined in the previous section, how can you detect the RAT and know for sure?
Check for suspicious processes with Activity Monitor
As mentioned earlier, a RAT will install its own program that runs in the background. To check for this, open Activity Monitor, select the CPU section, and order the running apps list by the most CPU usage.
Do you recognize the processes hogging the highest CPU percentage? If you don’t, Google their names. Then, force-quit them and see if they reappear. If they restart by themselves, you may have a problem.
Review installed applications in Finder
When a RAT installs its own program, there’s a good chance it will appear in the Applications folder in Finder. This is why it’s always good practice to check the Applications folder on a regular basis.
Go to Finder > Applications and see if there’s anything there that you don’t recognize. Run a web search for the name in case you did install it but forgot about it.
If you don’t recognize the app at all, delete it using CleanMyMac (we’ll get into this shortly).
Run CleanMyMac
The most efficient way to detect a remote access trojan is to run CleanMyMac powered by Moonlock Engine. CleanMyMac will find all kinds of threats on your MacBook, including RATs, and make it easy for you to quarantine and destroy them.
In the next section, we’ll outline how to run a CleanMyMac scan.
How to effectively remove a remote access trojan
So you’ve established that you have a remote access trojan. Now it’s time to go on the offensive and remove it. So, what do you do?
Disconnect from the internet
The first step is to disconnect from the internet. An internet connection is what the RAT needs to be able to work properly. So, by disconnecting from Wi-Fi, you’re depriving it of the fuel it needs to run.
Do a deep scan with CleanMyMac
The next step is to run CleanMyMac. Here’s how:
- Open CleanMyMac and select the Protection module on the left.
- If it’s your first time using the software, select Configure Scan first to select what you want to be scanned. Select everything, as well as Deep Scan.
- Click Scan. CleanMyMac will start methodically searching for all traces of the remote access trojan, as well as any other threats on your MacBook.
- When the remote access trojan has been found, CleanMyMac will present it to you in a comprehensive list. Select everything and click Remove.
Consider wiping and resetting your MacBook
CleanMyMac is highly thorough and will likely remove every trace of remote access trojan malware. But for extra peace of mind, you may also want to consider wiping and resetting your MacBook.
This is obviously a lot of work, as you’ll need to set up your MacBook from scratch. But to be 100% sure that the RAT is gone, it may be a good idea.
Change your passwords and enable 2FA
Assume everything is compromised. That means you should change all your passwords and enable 2-factor authentication on all of your accounts.
Also check the files on your laptop. Pay close attention to anything that contains sensitive information.
How do hackers deliver remote access trojans?
The best way to avoid getting a RAT is to understand how a hacker can deliver one to your device in the first place.
Malware-infected links
The easiest low-effort method is to send out links far and wide and then wait for someone to click on them. These links will either take the user to an infected website domain or to software that will start installing on your device.
Bundled inside legitimate software
Another method of installing software is to bundle it with legitimate software. When you install the real software, the RAT will get installed in the background.
Sending you an infected file via email
Infected email attachments are another low-effort way to spread RAT infections. Most major email platforms are now very good at detecting infected files, but they’re not infallible. Some may still slip through.
Exploiting security vulnerabilities
Operating systems like macOS are excellent at staying on top of security vulnerabilities and pushing out patches. But what if the vulnerability isn’t known yet?
The period between the vulnerability first appearing and Apple discovering it and pushing out a patch could be a big enough window for a RAT to take advantage of it.
Scanning for network misconfigurations
Another method a RAT can gain access to your computer is through your Wi-Fi network. If your network has no password and is publicly accessible, it’s child’s play for a hacker to gain access and introduce a trojan virus.
Infected USB drives
Have you ever seen a USB drive lying around and been curious about what’s on it? Well, curb that curiosity because the drive could have been left there intentionally by a cybercriminal hoping you will plug it into your MacBook and release the RAT.
How to protect your Mac from remote access malware
MacBooks are no different than any other type of personal computer when it comes to RATs and other malware. So it’s necessary to be vigilant about protecting your Mac from a RAT threat.
Be wary of links and email attachments
Obviously, we can’t tell you to never click on a link or email attachment. That would be impractical. But if someone you don’t know sends you a link or an attachment, don’t click it or open it. Even if you know them, do you trust them?
Sometimes, it’s safer to be paranoid.
Set up and run CleanMyMac
The remote access trojan solution that will protect you the most is running a strong anti-malware tool.
Download and install CleanMyMac. With real-time scanning, CleanMyMac will alert you the moment it detects any new threats — including remote access trojans. That way, you can deal with the threat before it gains a serious foothold on your device.
Avoid installing software outside of the App Store
Since RATs can be installed by being bundled software with other apps, it’s a good idea to mostly confine yourself to apps and software available inside the Apple Store.
Apple thoroughly scans and vets all apps in their store, so the chance of a RAT lurking there is slim to none. There may be times when you need to buy something from a developer outside of the App Store. Just be careful before buying and downloading. Stick to trusted names.
Install all system and app updates right away
If there is a known security vulnerability on your Mac, Apple will quickly push out a patch to fix the hole. So, when you see that there is an update waiting, you must install it as soon as possible.
It’s easy to ignore updates and say that you’ll get to them later. In the meantime, a RAT may gain access to your machine. So don’t do it later — do it now.
Make sure your network is configured correctly
To prevent a RAT from entering your network, ensure that the network is configured properly.
Since there are so many routers with different settings, it’s difficult to provide specific instructions in this regard. However, at the very least, ensure that you have encryption protocols enabled and have a very strong password set up to stop unauthorized intruders from coming in. This is also a good reason for you to avoid using public Wi-Fi.
A remote access trojan can cause a considerable amount of trouble, inconvenience, and chaos if it gets onto a targeted computer. But, as with all types of malware, the key is to educate yourself on its existence and then study the various ways to avoid it or defeat it.
Once you know what to avoid and what proactive steps to take to kill the RAT, you’ll be able to be on the offensive side and well on your way to protecting your valuable data.
This is an independent publication, and it has not been authorized, sponsored, or otherwise approved by Apple Inc. Mac and MacBook are trademarks of Apple Inc.
