If you work on a computer regularly, then you might be aware about Trojan horse virus and its affect on your computer. It is a virus, which gets attached to some files in your computer and programs that you download from internet. The main characteristic of this virus is that once it gets a way into your computer it starts destroying the files secretly. This is designed in the form of useful software, but it does just the opposite, as it poses many problems for your computer.
What Is Trojan?
A Trojan horse, or Trojan, is a type of malicious code or software that looks legitimate but can take control of your computer. A Trojan is designed to damage, disrupt, steal, or in general inflict some other harmful action on your data or network.
It acts like a bona fide application or file to trick you. It seeks to deceive you into loading and executing the malware on your device. Once installed, a Trojan can perform the action it was designed for.
A Trojan is sometimes called a Trojan virus or a Trojan horse virus, but that’s a misnomer. Viruses can execute and replicate themselves. A Trojan cannot. A user has to execute Trojans. Even so, Trojan malware and Trojan virus are often used interchangeably.
Whether you prefer calling it Trojan malware or a Trojan virus, it’s smart to know how this infiltrator works and what you can do to keep your devices safe.
How do Trojans work?
Here’s a Trojan malware example to show how it works.
You might think you have received an email from someone you know and click on what looks like a legitimate attachment. But you have been fooled. The email is from a cybercriminal, and the file you clicked on — and downloaded and opened — has gone on to install malware on your device.
When you execute the program, the malware can spread to other files and damage your computer.
How? It varies. Trojans are designed to do different things. But you will probably wish they weren’t doing any of them on your device.
How to recognize and detect a Trojan virus
Because Trojans are used as a delivery device for a number of different types of malware, if you suspect your device may have been breached by a Trojan, you should look for many of the same telltale signs of malicious software. These may include:
- Poor device performance: Is your computer or mobile device running slowly or crashing more frequently than normal?
- Strange device behavior: Are programs running you didn’t initiate or are other unexplained processes being executed on your device?
- Pop-up and spam interruptions: Are you noticing an uptick in the number of interruptions from browser pop-ups or email spam?
If your device is exhibiting these symptoms, it’s possible a Trojan virus has managed to sneak its payload onto your computer. Try searching your computer for any programs or applications you don’t remember installing yourself. Enter any unrecognized file names or programs into a search engine to determine if they are recognized Trojans.
Finally, if you haven’t already, scan your computer with antivirus software to see if it has uncovered a malicious file.
Examples of Trojan malware attacks
Trojan malware attacks can inflict a lot of damage. At the same time, Trojans continue to evolve. Here are three examples.
- Emotet banking Trojan. After a long hiatus, Emotet’s activity increased in the last few months of 2017, according to the Symantec 2018 Internet Security Threat Report. Detections increased by 2,000 percent in that period. Emotet steals financial information, among other things.
- Rakhni Trojan. This malware has been around since 2013. More recently, it can deliver ransomware or a cryptojacker (allowing criminals to use your device to mine for cryptocurrency) to infected computers. “The growth in coin mining in the final months of 2017 was immense,” the 2018 Internet Security Threat Report notes. “Overall coin-mining activity increased by 34,000 percent over the course of the year.”
- ZeuS/Zbot. This banking Trojan is another oldie but baddie. ZeuS/Zbot source code was first released in 2011. It uses keystroke logging — recording your keystrokes as you log into your bank account, for instance — to steal your credentials and perhaps your account balance as well.
How Trojans impact mobile devices
Trojans aren’t problems for only laptop and desktop computers. They can also impact your mobile devices, including cell phones and tablets.
In general, a Trojan comes attached to what looks like a legitimate program. In reality, it is a fake version of the app, loaded up with malware. Cybercriminals will usually place them on unofficial and pirate app markets for unsuspecting users to download.
In addition, these apps can also steal information from your device, and generate revenue by sending premium SMS texts.
One form of Trojan malware has targeted Android devices specifically. Called Switcher Trojan, it infects users’ devices to attack the routers on their wireless networks. The result? Cybercriminals could redirect traffic on the Wi-Fi-connected devices and use it to commit various crimes.
How to help protect against Trojans
Here are some dos and don’ts to help protect against Trojan malware. First, the dos:
- Computer security begins with installing and running an internet security suite. Run periodic diagnostic scans with your software. You can set it up so the program runs scans automatically during regular intervals.
- Update your operating system’s software as soon as updates are made available from the software company. Cybercriminals tend to exploit security holes in outdated software programs. In addition to operating system updates, you should also check for updates on other software that you use on your computer.
- Protect your accounts with complex, unique passwords. Create a unique password for each account using a complex combination of letters, numbers, and symbols.
- Keep your personal information safe with firewalls.
- Back up your files regularly. If a Trojan infects your computer, this will help you to restore your data.
- Be careful with email attachments. To help stay safe, scan an email attachment first.
A lot of things you should do come with a corresponding thing not to do — like, do be careful with email attachments and don’t click on suspicious email attachments. Here are some more don’ts.
- Don’t visit unsafe websites. Some internet security software will alert you that you are about to visit an unsafe site.
- Don’t open a link in an email unless you are confident it comes from a legitimate source. In general, avoid opening unsolicited emails from senders you don’t know.
- You don’t download or install programs if you don’t have complete trust in the publisher.
- Don’t click on pop-up windows that promise free programs that perform useful tasks.
- Don’t ever open a link in an email unless you know exactly what it is.
Steps to Follow for Manual Removal
There are some simple steps, which you can follow to remove Trojan horse virus manually. These include:
- Recognize the Trojan: After recognizing a file infected with Trojan horse, it becomes easy to remove it. Usually, your system will give you DLL error, which is associated with Trojan attack. You can copy the error and find out about the affected exe file online.
- Stop the function of system restore: If you forget this step, then it will restore the files you will delete.
- Restart you computer: when you restart, press F8 and then select safe mode to start your computer.
- Go to Add or Remove Programs: You will find this in the control panel, and then remove the programs affected with Trojan horse.
- Remove extensions: To delete all files of a program, you should remove them from Windows System folder.
Once you have done the following steps, you should restart your system in normal mode this time.
Other ways of removing the virus
Another Way of Removing Trojan Manually:
- Display the hidden folders from the folder options
- Then restart the system in safe mode
- Then stop the processes that are associated with Trojan virus.
However, to complete these steps, you will have to edit your system’s registry.
The Final Thought about Trojan
A final note on Trojans for history and mythology buffs.
Trojans take their name from the hollow wooden horse that the Greeks hid inside of during the Trojan War. The Trojans, thinking the horse was a gift, opened their walled city to accept it, allowing the Greeks to come out of hiding at night to attack the sleeping Trojans.
In the same way, if you are the victim of Trojan malware, you could find yourself on the losing side. It pays to stay alert, be careful, and don’t take chances. No matter what type of devices you are using to stay connected.