Like the mythical Greek trap, Trojan horse infections lure you in with a false sense of security before releasing a deluge onto your operating system. The worst part is it can be wrapped up in working software, so the damage is done long before you know what hit you. Using the right tools can help you remove a Trojan and any malware it happens to release, but preventative tools and a little information can save you the headache in the first place.

If you learn how to identify possible Trojan infections, or at least where they usually come from, you can reduce your chances of being hit. A little bit of knowledge of how they work will help you identify them early. Education and prevention are your best tools, but good cybersecurity software could be your saving grace.

What is a Trojan?

A Trojan is malware that you have to download physically. They can come from pirated software, email attachments, torrenting, file sharing, and any other method of transferring data from one device to another.

Once a Trojan is on your device, it releases viruses or other malicious software. This can encrypt and lock your data to request a ransom, delete data, use your machine as a soldier in a DDoS attack, and so much more. Like the Trojan horse in the ancient fable, you let it in, and then, bam, you’re hit with a ton of Greek soldiers. Well, not really — you’re hit with malware, but it wreaks just as much havoc.

Trojans are often lumped together with viruses because they can contain viruses, but a Trojan and a virus are different. A virus can appear on your computer by opening a file, stumbling across the wrong website, or using an infected flash drive.

To install a Trojan, you have to perform an action like a download or even just say “yes” to a pop-up that then installs the Trojan. No matter if you want to remove malware, a Trojan horse virus, or just tighten up vulnerabilities, a good antivirus program will help you figure out what’s going on.

Types of Trojans

There are quite a few different types of Trojans out in the wild, like Backdoor Trojans, DDoS, and Downloader Trojans. Oftentimes, they’re hidden in a tool you download that’s supposed to be helpful. The tool might even work, but you’ve also released a Trojan onto your hard drive without knowing.

No matter where they come from, Trojans all have the same kinds of end goals. The main functions of Trojans are to:

• Delete data
• Change data
• Encrypt data
• Copy data
• Send and/or receive files
• Slow devices
• Slow networks

How Trojans infections spread

Since Trojans have to be downloaded, they can be spread in a variety of ways.

You may download something you think is helpful software that also contains a Trojan. It can come in the form of an email attachment you open. Trojans also exist on websites that download something to your device after you visit and arbitrarily click “yes,” not knowing why the site is sending you something.

You can be hacked through a fake chat, infected network like public Wi-Fi, or downloaded games, music, AirDrops, and much more. We once accepted a flash drive from a creepy guy our friend knew who said he got us a movie we wanted to see. It didn’t contain a Trojan (we checked), but it absolutely could have.

For gamers, torrenting and P2P downloads from unrecognized user profiles may also contain Trojans, viruses, malware, ransomware, or keylogger programs that watch what you type online. There’s no limit to what can be installed on your device from a Trojan. If someone you don’t know is offering to send you a program for free or low cost, be wary.

Recognizing Trojan infections

Your Trojan could go a long while without being discovered. Since it can hide in working software, you might not even know you’ve downloaded it until weird things happen. Indicators of Trojan infection include:

• New programs installed/visible in the start menu
• Fake pop-up alerts
• Screenshots you aren’t taking
• Sounds or photos popping up
• Computer reboots on its own
• Slow startup
• Programs running on their own

Most of these warning signs are actions taken on your computer that you didn’t take yourself. If you share your device with other household members, don’t just assume they changed something. Communicate with each other to determine if you really are the victim of a Trojan attack. If you’re suspicious it may be an attack, it’s best to run tests with reputable software to check for an infection.

We say reputable software because there is plenty of free antivirus software available that may actually be a hiding space for Trojans. Free software that doesn’t come from a reliable source is always a dicey choice, so making sure you use a reputable tool will help you identify and remove the issue. Once you’ve chosen a good antivirus that recognizes and removes Trojans, you should perform a full scan.

Preparing to remove a Trojan

Once you’ve identified that you do indeed have a Trojan on your computer, you’ll need to remove it. Before you remove Trojans, back up your data, preferably to a cloud storage service or external hard drive. Be careful to scan the external hard drive so the malware can’t sneak onto it and reinstall itself on your computer. You’ll want to make sure your software and operating system are up-to-date.

Delete any programs you think may be suspicious, but be careful not to delete anything necessary to actually use your computer. Geek Squad has seen many a tear from a panicked customer who just deleted core components of their operating system. Finally, disconnect from the internet.

Most antivirus software will still run without an internet. You won’t have the most updated version if you leave your computer offline too long, but for the purpose of removing a Trojan, you should be fine.

Then, if you’re comfortable, reboot your computer in safe mode. This will help keep the virus from blocking your attempts to remove it. If you aren’t comfortable with safe mode, you can still try to remove the virus with your antivirus software. We would suggest running this process repeatedly until you get a clean scan.

How to remove a Trojan with antivirus software

A good antivirus software should do all the work for you. It should also remove all remnants of the Trojan, so you don’t have to worry about becoming reinfected. While removing a Trojan on your own is possible, we seriously recommend using a professional antivirus. If you don’t, you could potentially delete an important process in your computer’s operating system and render your device inoperable.

First, you’ll want to run a scan on your entire system; no quick scans here. Do the whole thing. Depending on your software, it could take as little as five minutes or well over an hour. Make some tea, pop on a show you like, and it’ll likely be done before you know it.

Once your scan is complete, follow the instructions to quarantine and remove any nasties your program finds. When you’re done, reboot your computer and run the scan again. Repeat until you get a clean scan.

Best antivirus software for Trojans

Including antivirus software is just a must in this age of hackers and ransomware. You’ll want to make sure you have a comprehensive antivirus that protects against viruses, Trojans, and all forms of malware, including ransomware, spyware, and adware. This way, if you do accidentally pick up a Trojan, you have a line of defense protecting you. We’ve listed some of the best antivirus software:

• Norton 360: Norton 360 has been around a long time and is ready to fight against the Trojans, viruses, and malware floating around the internet. It includes a variety of plans to fit your needs and budget. For complete protection, go for the Select plan with LifeLock to enjoy a VPN, cloud backup, and identity theft protection.
  
  Get Norton 360 | Read Norton 360 Review
• CleanMyMac X: It’s a myth that Macs are completely safe. While macOS has a lot of protections, CleanMyMac X offers even more, including defense against Trojans. You’ll also enjoy performance enhancements and the ability to delete data. If a data-stealing Trojan does get through, CleanMyMac X offers tools to remove it. Now Windows users aren’t the only ones protected against malicious programs.
  
  CleanMyMac X | Read CleanMyMac X Review
• Bitdefender: If you’re looking for a free antivirus, Bitdefender has that. If you’re looking for a more robust, paid antivirus, Bitdefender has that too. It protects against viruses, malware, Trojans, and, depending on the plan you choose, so much more.
  
  Get Bitdefender | Read Bitdefender Review

Tips to prevent Trojan infections

Now that you’ve removed the Trojan, make sure you can protect yourself from getting another one. Preventative steps are fairly easy to institute and take minimal effort. This will save you a headache in the future if you add to your battle armor now.

• Use a VPN on public Wi-Fi networks
• Only download software from reputable sources
• Reject downloads from websites if prompted
• Verify email attachments before opening
• Keep your software updated to patch any security issues
• Use antivirus software with real-time protection to warn against shady downloads
• Setup a firewall
• Configure your AirDrop settings to only allow contacts

Trojan FAQ

Bottom line

Cybercriminals are becoming increasingly sophisticated in their attack methods, and even the most savvy of techies can get hit. The most important thing is to stay vigilant and know the warning signs of infection. Once you can recognize something may be wrong, you can deploy your army of verified tools to fight the invasion.

Make sure you’re using as many preventative measures as possible to stay safe. By employing good antivirus software, a VPN, and a firewall, you’ll increase your chances of avoiding infection. Also, make sure only to download verified software. Not only will you avoid Trojans and malware, but you’ll also get the support you need in case something goes wrong.

No matter what you do, it’s important to stay aware of what’s going on with your devices. Even the most protected computer can get an infection. If you know something looks off, don’t be afraid to scan, clean, and repeat.

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Author Details

Mary James

About the Author

Mary lives in Los Angeles and has been a cybersecurity writer for over five years. With a B.S. in Liberal Arts from Clarion University and an M.F.A. in Creative Writing from Point Park University in Pittsburgh, her career in online security began in sales and content creation for a private cybersecurity firm.