what is a trojan computer virus?

I ran my anti-virus software and i always seem to have those i just want to what it is and if it poses a threat to my computer

9 Answers

  • Anonymous
    1 decade ago
    Favorite Answer

    What is trojan?

    Trojan is a program installed on computers usually without the owners permission or knowledge and are used to gain access by unauthorised people to the computer.

    Trojans appear to be safe, but they often hide malicious computer code that can spread a virus or worm.

    Trojans can sit harmlessly on a computer until the hacker activates it and gains access.The term comes from the a Greek story of the Trojan War, in which the Greeks give a giant wooden horse to their foes, the Trojans, ostensibly as a peace offering. But after the Trojans drag the horse inside their city walls, Greek soldiers sneak out of the horse's hollow belly and open the city gates, allowing their compatriots to pour in and capture Troy.

    How do trojans work?

    Trojans typically consist of two parts, a client part and a server part. When a victim (unknowingly) runs a Trojan server on his machine, the attacker then uses the client part of that Trojan to connect to the server module and start using the Trojan. The protocol usually used for communications is TCP, but some Trojans' functions use other protocols, such as UDP, as well. When a Trojan server runs on a victim’s computer, it (usually) tries to hide somewhere on the computer; it then starts listening for incoming connections from the attacker on one or more ports, and attempts to modify the registry and/or use some other auto-starting method.

    It is necessary for the attacker to know the victim’s IP address to connect to his/her machine. Many Trojans include the ability to mail the victim’s IP and/or message the attacker via ICQ or IRC. This system is used when the victim has a dynamic IP, that is, every time he connects to the Internet, he is assigned a different IP (most dial-up users have this). ADSL users have static IPs, meaning that in this case, the infected IP is always known to the attacker; this makes it considerably easier for an attacker to connect to your machine.

    Most Trojans use an auto-starting method that allows them to restart and grant an attacker access to your machine even when you shut down your computer. Trojan writers are constantly on the hunt for new auto-starting methods and other such tricks, making it hard to keep up with their new discoveries in this area. As a rule, attackers start by “joining” the Trojan to some executable file that you use very often, such as explorer.exe, and then proceed to use known methods to modify system files or the Windows Registry.

    Categories of trojans

    Trojans are broken down in classification based on how they breach systems and the damage they cause. The seven main types of Trojan horses are:

    * Remote Access Trojans

    * Data Sending Trojans

    * Destructive Trojans

    * Proxy Trojans

    * FTP Trojans

    * security software disabler Trojans

    * denial-of-service attack (DoS) Trojans

    How to secure your PC from trojans?

    * Never open files which you are offered by an unknown party. This applies to all types of files received through all possible channels.

    * Ensure that programs such as Microsoft Word and Excel do not automatically run macros.

    * Ensure that your e-mail program does not automatically open attachments for you.

    * Never accept files which are offered via MSN Messenger or similar chat programs.

    * Do not accept files which you have to install in order to view a web page.

    * Use a specialist trojan scanner to detect passive trojans.

    * Make sure you always download the latest updates for these programs. Trojan scanners are not effective without updates.

    * Ensure that your operating system automatically receives new updates and patches.

    * The producer of your operating system will use these updates in order to close any security holes. Special trojan scanners are available to help you detect trojans. Like your virus scanner, a trojan scanner requires updates in order to recognise the latest trojans. You can use a trojan scanner to remove trojans. It will not protect you against trojans, but can be used to remove trojans from your computer.


    try manual removal instructions

  • 5 years ago


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  • 1 decade ago

    a virus is like a worm a bit of bad code that copies it's self on other files and computers a Trojan is nothing more then a program you can't see running it normally has a server running on it that allows others to access your computer.

  • Anonymous
    1 decade ago

    Its a virus that hides in another file,

    named after the trojan horse


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  • 1 decade ago

    yes indeed this torjan is a kind of viruses that will send some kind of information aobout your computer so if you have some billions in your account you should start thinking seriosly about it because some good hacker might get your account details and steel you or did some thing bad about you so you hav e to be afraid about your self and your computer....

  • Anonymous
    1 decade ago

    it sneaks into your computer disguised as something else just like the Trojan Horse from Helen of Troy fame.

    they are dangerous and they can wreak havoc to your computer.

  • 1 decade ago

    its a virus that can multiply if it isnt stop fast it was invented by some lil hacker brat and named it after the romans

    if it isnt stop it will spread throught ur hole pc and then u will have to format ur pc and start from scratch

  • 1 decade ago

    its a virus which slows down the speed of your computer.

  • 1 decade ago

    it is really hard to get off and it screws with everything

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