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Trojan Horse in Information Security

  • Last Updated : 18 Feb, 2021

The name of the Trojan Horse is taken from a classical story of the Trojan War.  It is a code that is malicious in nature and has the capacity to take control of the computer. It is designed to steal, damage, or some harmful actions in the computer. It tries to deceive the user to load and execute the files on the device. After it executes, this allows cyber criminals to perform many actions on the user’s computer like deleting data from files, modifying data from files, and more. Now like many viruses or worms, Trojan Horse does not have the ability to replicate itself.

For example: 
There was a Trojan that disguised itself as a game. Many users have downloaded this game and that secretly turned into a self-replicating virus. The game was a simple theme based game, but it started to back up all the files of the drive where the user would access them. The Trojan turned to be harmless, and it was easy for them to fix. So this was identified as Trojan because it did not disclose the virus.

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Now after this many Trojan viruses or Malware came which turned out to be a threat or the most popular malware attack. As these Trojans can be found as versatile, this is used by many Online Criminals for malware attacks. The Trojans are a bit tougher to be identified. Trojans can be found in MP3 songs that the user may have downloaded, or downloading games from an unsecured website, or the advertisement that pops up when the user is browsing the page.

Many people have been infected by Trojans without realizing it. This type of Trojans is called Direct-Action-Trojans. It can’t spread to any user because when a virus infects the system show some indications that it has been affected by the virus. 

For example:, there is a direct action Trojan name Js. ExitW. It can be downloaded from many malicious sites. The effect of the Js. ExitW is to make the computer fall in a never-ending loop of start and shutdown. The Trojan does not do any damage which could be considered dangerous. But we should be aware that there are many Trojans that are far more dangerous.

Some features of the Trojan horse are as follows :

  • It steals information like a password and more.
  • It can be used to allow remote access to a computer.
  • It can be used to delete data and more on the user’s computers.

How Trojans are used?

There are many ways that it can be used :

  1. Spy – 
    Some Trojans act as spyware. It is designed to take the data from the victim like social networking(username and the passwords), credit card details, and more.
  2. Creating backdoors –
    The Trojan makes some changes in the system or the device of the victim, So this is done to let other malware or any cyber criminals get into your device or the system.
  3. Zombie –
    There are many times that the hacker is not at all interested in the victim’s computer, but they want to use it under their control.

Now there are many Trojans which is designed to perform specific functions. Some of them are: –

  1. Trojan-Banker –
    It is designed to steal the account data for online banking, credit and debit cards, etc.
  2. Trojan_Downloader –
    It is designed to download many malicious files like the new versions of Trojan and Adware into the computer of the victims.
  3. Trojan-Dropper –
    It is designed to prevent the detection of malicious files in the system. It can be used by hackers for installing Trojans or viruses in the victim’s computers.
  4. Trojan-GameTheif –
    It is designed to steal data from Online Gamers.
  5. Trojan-I’s – 
    It is designed to steal the data of login and passwords like: -a. skype b. yahoo pager and more.

Other Trojans can be also be used like: -Trojan-notifier, Trojan-clicker, and more.

Indications that the system has been affected by the virus: 

  • First the system or the device where it has been affected will be slow.
  • The user will experience the files to be opening much slower.
  • The user can also experience a direct shutdown of the pc.

Advantage of the Trojan Horse:

  • It can be sent as an attachment in an email.
  • It can be in some pop-up ads that we find on the web page.

Disadvantages of the Trojan Horse:

  • It can’t manifest by itself. It requires the implementation of the .exe files.
  • It remains undetected and starts its execution when the user is doing any online transaction activity.

How to prevent this virus: 
The most basic prevention method: –

  1. Donot download anything like the images, audios from an unsecured website.
  2. Do not click on the ads that pop up on the page with some advertisements for online games.
  3. Do not open any attachment that has been sent from an unknown use.

The most common method: 
The user has to install the anti-virus program. This anti-virus program has the capacity to detect those files which are affected by a virus.

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