The term “Trojan virus” can refer to a wide spectrum of different virus types, but they all share something in common — the shipping procedure. Like the Trojan Horse of the early Greeks, a Trojan virus hides, typically within legitimate applications. When the user installs the software, that is when Odysseus and the boys jump out, ready to cause mayhem.
Trojan viruses are most commonly obtained from downloading pirated software, but not necessarily. Sometimes reputable download sites can accidentally host malware infected files, due to a light screening procedure. We are not going to drop names, but it is entirely possible to obtain a valid copy of trial applications from a software hosting site, only to discover that the application has infected you with malware such as PUPs (potentially unwanted programs) or other small critters.
How to find and discover a Trojan virus
Okay, so here is the thing. We already discussed that “Trojan virus” really refers to the shipping method, so you are not really hunting for a Trojan virus. You are hunting for any sort of virus which was delivered via the Trojan method. Got it?
So you will need to know about the most common signs of your computer being infected with malware, any sort of malware. That’s a fairly broad selection of definitions, so we’ll list a few of the most frequent.
Significant computer lag: Some undesirable apps or apps running in the background. Could be a Cryptominer if you detect unusually high CPU use, but essentially, something undesirable is operating in the background.
Popup ads on your desktop: This is a traditional virus symptom, essentially your computer will begin displaying plenty of popup ads even on your desktop. It is sort of fallen out of popularity with cybercriminals, however, especially since its a direct indication that your computer was infected.
Programs you do not recall installing: These are classic PUPs (potentially unwanted programs), which may be bundled together with the installation of the software you really wanted. Now, most installers ask if you would like to optionally install these additional programs, but not always.
Browser homepage changed: When the homepage of your browser has been changed, it is definitely a sign of either a cookie extension or any other type of malware.
Unusual network traffic: If you start Task Manager (or the Linux and Mac equivalent) and detect unusual network traffic, including a whole lot of outgoing data even if you aren’t doing anything about the internet, that is a great indication that something fishy is happening.
Files or folders that can not be deleted: If you become aware of some new folders or files you do not remember making, and you attempt to delete them just to be advised that these documents are “already in use”, that is classic virus activity. Those files are probably linked to the very first thing on this list we mentioned.
Antivirus will not launch: Many viruses have built-in defense mechanisms to disable your antivirus, or completely prevent it from launching. If your antivirus won’t start or cancels unexpectedly in the middle of a scan, that is a classic virus symptom.
You cannot search about antivirus: Many viruses will actually prevent you from searching the internet about antivirus or other cybersecurity topics. The virus will redirect your browser when you attempt to see sites for antivirus software.
Computer design changed or erroneous letters: Viruses can delete or alter important system files, which may cause issues with your computer hardware. This is not typically desired by cybercriminals because it will alert the user to the existence of a virus, but it still occurs. If your keyboard layout suddenly changes or forms the wrong characters, it might be an issue with the computer itself. But if you swap out the keyboard and still have the problem, it is a sign of some kind of malware infection that has affected files pertinent to hardware. ‘
Removing the virus from your computer
First, you will need to think of any applications you recently installed. With a tool like CCleaner, you can arrange the applications installed on your computer by most recently installed. You should carefully scan this for whatever you do not remember installing.
Running a virus scan should care for the problem in many situations, but some viruses can be particularly stubborn. Especially those viruses which have managed to corrupt your antivirus software. In this situation you will want to roll your sleeves up and get a bit dirty.
You might have to try booting your computer into Safe Mode, and running the antivirus software from there. Also try Safe Mode with no media, to prevent the virus from communicating with its home base.
If your antivirus still will not launch in Safe Mode, then you will likely need an antivirus rescue disk. This is a bootable antivirus, meaning it runs the antivirus scan without actually launching your operating system. There are lots of available, but if your computer is already infected, it could be nearly impossible to download the application and make a bootable disk out of it. In cases like this, you’ll require another computer.