Virus, worm, trojan ........ what is the different between them?

Answer 1

All 3 are malware of one form or another. They vary in how they infect a system, and whether or not they can replicate themselves to other systems.

Viruses are "parasites" - they attach to files (executables, Word macros, etc). They self-replicate, but require some sort of user interaction to infect a system (opening a document, running a program, etc.) Typically, viruses alter the program they're attached to in order to run their commands.

Worms are standalone - they attack system vulnerabilities (such as network services). These self-replicate, and require no user interaction - which leads to them spreading quickly.

Trojans are, like the original trojan horse, not what they seem. They're the bait-and-switch model - programs that claim to do one thing while doing something else. These do not replicate, and require user intervention to infect a system.

Answer 2

A computer worm is a self-replicating computer program. It uses a network to send copies of itself to other nodes (computer terminals on the network) and it may do so without any user intervention. Unlike a virus, it does not need to attach itself to an existing program. Worms almost always cause harm to the network, if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer. Trojan horse, also known as a trojan, is malware that appears to perform a desirable function but in fact performs undisclosed malicious functions. Therefore, a computer worm or virus may be a Trojan horse.

Answer 3

Trojans are usually tracking type programs or code that "watch" wha tyou do on your pc and try to override certain settings to divert you to wherever it is it wants you to go, and could potentially cause critical system errors by doing so.
A worm is something that embeds into your system and slowly but surely can turn off or completely undo programs and operating systems.
A virus is something that "infects" your computer in a variety of ways, usually causing system crashes and program errors and eventually can cause the system to become so unstable that it is rendered unuseable.

Answer 4

Trojans are usually tracking type programs or code that "watch" wha tyou do on your pc and try to override certain settings to divert you to wherever it is it wants you to go, and could potentially cause critical system errors by doing so.
A worm is something that embeds into your system and slowly but surely can turn off or completely undo programs and operating systems.
A virus is something that "infects" your computer in a variety of ways, usually causing system crashes and program errors and eventually can cause the system to become so unstable that it is rendered unuseable.

Answer 5

While all cause harm, each slightly differentiates from others:

Virus: Self-replicating, malicious code that attaches itself to an application program or other executable system component and leaves no obvious signs of its presence.

Trojan - a program that appears desirable but actually contains something harmful - got the name from ancient Greek mythology.

Worm - a software program capable of reproducing itself that can spread from one computer to the next over a network; "worms take advantage of automatic file sending and receiving features found on many computers"

Most malicious softwares can be a combination of all of the above.

Answer 6

It's a matter of propagation.

A virus (in most cases) can not self-propagate but can self-replicate and it will require you to take an action (such as double click on an executable), and will attach copies of itself as it goes to local (or even networked under certain circumstances) executables.

A Worm is very similar but it can self-propagate and multiply by exploiting known weaknesses of the target system (such as missing updates). A worm can carry viral code or just slow down networks by it's multiplication and self-propagation techniques.

A trojan, same as a virus can not self-propagate and it depends on it's camouflage to lure a victim to execute it. Such as a fake email, or a virus hidden inside a free silly game.

All of them carry some "viral" code in them and as such commonly, nevertheless a bit erroneously, are called viruses.

Answer 7

All are viruses. You insatll a standard antivirus soft ware such as Norton, AVG , Avast ( free antivirus software and Ad-aware, Ewido ( free spyware removers). You can download free softwares at
http://fixit.in/antivirus.html and http://fixit.in/spywareremover.html

Answer 8

virus is any kind of file you get from junk email, spam and other crap people try to send you

trojans are files that disguise themselves and infects your computer

worms are the worst

not really good at explaining them, look at the other answers

Answer 9

a virus has different ways of getting in to your computer and some cause adware some open bad sites ect....bloodhounds are spyware they are worse they steel credit cards

Answer 10

They are all bad! Get a good antivirus program to get you rid of them! Here you have some free options:
http://askcomputerexpert.ws43.com/download/security.htm