Trojan Horse virus: what it is, how to detect it and remove it

ALL ABOUT COMPUTER SCIENCE AND TECHNOLOGY

Release your testosterone and observe the extreme increase in muscle mass.

Publish perfectly-optimized content in 1-click




Trojan Horse virus: what it is, how to detect it and remove it


Among the most dangerous computer threats we can run into, the trojan virus certainly stands out , an advanced level malware designed to overcome the defenses of any PC and ensure total control of the device by computer pirates.






What is a Trojan horse: meaning trojan horses


Trojan horse or (simply trojan ) is a special type of malware designed to take complete control of the device.
These malware are capable of affecting both PCs and mobile devices (smartphones and tablets) and, once launched, they can damage the system in various ways:

.Deactivate any type of antivirus and firewall
.After destroying the device's defenses it can execute other malware
.Exploit bugs in the system to make changes as an administrator
.Install unwanted software or software capable of spying on the device
.Steal personal data, transfer files and folders, and copy credit card numbers
.Take total control of the device.


All these characteristics make the malware in question extremely dangerous , given the damage it is capable of bringing to any modern device.


Types of Trojan Horses

As can be easily understood, there is not a single variant of this dangerous malware that can specialize in a specific task (to be completed by deception).

The main types of trojans are:


backdoor
This category of malware allows remote access to systems, exploiting bugs or doors left open by previous infections or by the operating system. Backdoors are used by hackers to control devices, steal information, and download other malware;

spyware
This category of malicious software spies on user activity by copying and sending hackers access data to their online accounts, as well as passwords and other identification data (such as credit card numbers);

zombie trojans
These are probably the most insidious, as they operate by taking control of the computer (often leaving no trace of the infection) and secretly connecting the device to the hacker's control network (also called a botnet). In this way, the PC or mobile device can be woken up at any time and carry out DDoS attacks against a network or website.

trojan downloaders
These malware download and execute other malicious malware after damaging the defenses of the operating system or installed antivirus. Newly downloaded malware is often even more dangerous than the trojan itself (ransomware or keyloggers are often downloaded);

send messages and SMS automatically
on mobile devices they operate by sending messages and SMS continuously, draining the credit or spreading the infection via messaging apps.
If we are dealing with any of these malware, it is advisable to act as soon as possible to avoid damage to the operating system but also identity theft, money theft and totally compromised devices .


How a Trojan works


This type of malware acts in a sneaky way, as the origin of the name suggests (inspired by the famous Trojan horse narrated in Virgil's Aeneid); in fact, the trojan hides inside legitimate files or inside copies of famous applications (in most cases in a modified version to avoid license costs), so as to go unnoticed at a first check by the user .

After starting the installation of the program or app, the malware immediately begins its malicious action , damaging files and starting up automatically together with the system: the infection is now in progress and only with the right tools is it possible to stop it before it it's too late.

Famous Trojans
To understand the extent of the damage caused by this malware we can rely on computer history , recounting the exploits of the most famous trojans since the birth of modern computers:

ANIMAL : released in 1975, considered by all as the first trojan. It was a simple game in which the user had to answer twenty questions. In reality, this program copied computer files to shared folders, allowing all users on the network to see the content without a password;
Beast : a powerful backdoor trojan appeared in 2002, capable of infecting almost all versions of Windows and making them unusable after a short time;
Zlob : another backdoor trojan appeared in 2005 which spread via fake ActiveX codec for Internet Explorer, causing massive damage to all affected workstations;
Zeus : one of the most famous keylogger trojans appeared in 2007, able to easily steal credit card data and login credentials of any account or from any browser;
Torpig (also called Sinowal and Mebroot) : powerful trojan appeared in 2008 that deactivated the antivirus and allowed total access to the PC by the bad guys;
Cryptolocker : the most famous of modern trojans, which appeared in 2013 and is still in circulation (in various forms and under various names). This malware uses trojan techniques to infect your computer and once it "opens the way", it uses its own ransomware component to encrypt your personal files and folders.

These are just some of the malware that have made the history of computing, causing huge damage both from a financial point of view and from a productivity point of view (since the affected systems became totally unusable).


How Trojans are delivered: methods of infection

The malware we are analyzing is extremely difficult to identify, given that in most cases the trojan presents itself as an apparently useful file.

The trojan virus can hide in:

a free program , modified to carry the trojan component during installation or when starting the program itself;
an email attachment : this is the most used method in the past, with apparently legitimate emails hiding infected attachments or links to infected pages;
in a video game : even video games can carry malware, especially pirated versions. The trojan hides in the pirated game installer or bootable crack components needed to pass license checks;
in a modified paid application : just like in video games it is possible to run into this infection by starting a crack for a paid program or directly downloading the modified program to bypass licenses and subscriptions;
while watching illegal streaming : another very common method involves watching illegal streaming content on sites modified to carry a trojan or full of misleading advertising.
There are also other methods (propagation on the same LAN and infected USB sticks) but they are much less common than those seen above.


How to prevent infections


All antiviruses on the market provide security modules designed to stop trojans before they can do any kind of damage to your PC. Below you can find a table with the best antivirus that we recommend you try on your computer.

The recommended antiviruses protect in real time from any type of trojan threat , blocking the replication, start-up and modification of the system by the malware, as well as blocking all the ways used by the threat to spread (web site analysis, email control and check for new files).



Preventing infection is the best strategy

We always use an antivirus and an updated operating system, we prefer paid antiviruses over free ones and we always pay the utmost attention when downloading installers from unknown sites or downloading applications outside the official channels (in especially on mobile).