What is the difference between a virus and a worm?

Answer 1

A virus is a program that is designed to spread from file to file on a single PC, it does not intentionally try to move to another PC, and it must replicate, and execute itself to be defined as a virus.

A worm is designed to copy itself (intentionally move) from PC to PC, via networks, internet etc.

A worm doesnt need a host file to move from system to system, whereas a virus does.

So worms spread more rapidly then viruses.

The word 'Virus' has become a common term a lot of people use to refer to worms and trojans too. Which is not exactly correct.

Answer 2

"Virus" has become a generic term that includes all the malicious ways your computer can be attacked. Viruses are distributed by making copies of themselves or replication. Sometimes the replication itself causes damage to your hard disk. Sometimes the accumulative effect of replicating again and again disables the computer. Sometimes the energy used by replication takes over the system and there's no computer energy left. Here's a short list of different kinds of computer diseases:

A Virus is a program that piggy-backs on other programs. It can be attached to a Word or Excel file. Each time the file is run, the virus runs too. It attaches itself to other programs and continues to reproduce.

An email virus is a special type of virus sent as an attachment to an email message. It replicates by automatically mailing itself to everyone in the recipients email address book.

A Worm uses computer networks to replicate itself. It searches for servers with security holes and copies itself there. It then begins the search and replication process again.

A Trojan Horse is a computer program masquerading as a game or a "cute" program. However, when it runs it does something else - like erasing your hard drive or blocking your screen with a graphic will not go away.

Some viruses use several of these in combination to replicate themselves. It is disturbing that people actually spend large amounts of time and creative energy putting these devious things together. But they do and will continue to do so. The best protection is to get an anti-virus program and install it BEFORE you have any virus problems. Too many people find out they have a virus only after sending it off to all their friends and business associates. It's simply not worth the risk. Norton and McAfee are the most common anti-virus programs for home and small business use. Be sure to install the updates regularly. If you have an old version, get updated. New viruses are being created every day, it is important to keep your anti-virus software up to date. When your anti-virus program pops up and tells you it has detected a virus, always choose the option to fix it.

Here are some tips on recognizing viruses in email attachments:

Once you were safe from viruses if email attachments were not opened, however, this is no longer true. Make sure you have the most current updates from Microsoft for your operating system. These are patches for holes that virus creators exploit in the Windows operating system. Select "Windows Update" from your menu system and follow the directions. If you have a dial up connection, this can be very tedious, but it's worth the effort.

Most viruses come from opening an attachment that comes with an email. Basically, don't open an attachment that comes from someone you don't know. If it's from someone you know, stop and think. Does it have a reasonable introduction in the email? If the email contains nothing but the attachment or only has a brief note like "I'd like your advice on this" or "Here's something cool" it is suspect. If the attachment is an executable file (ends in .exe or .com), it is also suspect. Don't open suspect attachments.

What Is a Virus?A computer virus attaches itself to a program or file enabling it to spread from one computer to another, leaving infections as it travels. Like a human virus, a computer virus can range in severity: some may cause only mildly annoying effects while others can damage your hardware, software or files.

Almost all viruses are attached to an executable file, which means the virus may exist on your computer but it actually cannot infect your computer unless you run or open the malicious program. It is important to note that a virus cannot be spread without a human action, (such as running an infected program) to keep it going.

People continue the spread of a computer virus, mostly unknowingly, by sharing infecting files or sending e-mails with viruses as attachments in the e-mail.

What Is a Worm?A worm is similar to a virus by design and is considered to be a sub-class of a virus. Worms spread from computer to computer, but unlike a virus, it has the capability to travel without any human action. A worm takes advantage of file or information transport features on your system, which is what allows it to travel unaided.

The biggest danger with a worm is its capability to replicate itself on your system, so rather than your computer sending out a single worm, it could send out hundreds or thousands of copies of itself, creating a huge devastating effect. One example would be for a worm to send a copy of itself to everyone listed in your e-mail address book. Then, the worm replicates and sends itself out to everyone listed in each of the receiver's address book, and the manifest continues on down the line.

Due to the copying nature of a worm and its capability to travel across networks the end result in most cases is that the worm consumes too much system memory (or network bandwidth), causing Web servers, network servers and individual computers to stop responding. In recent worm attacks such as the much-talked-about Blaster Worm, the worm has been designed to tunnel into your system and allow malicious users to control your computer remotely.

Answer 3

Trojan horse- It is a program, using this program it will make the victim system to make listen on particular port, so that attacker can do anything on your system, i.e. he can tamper with, steal, and destroy the data etc...., a Trojan horse wont spread in to the system like a virus so it won't effect the system performance.

virus- It is a malicious program, using this program it will damage your system, by injecting the virus in to another programs are files, so that it will regrade your system performance. Virus will come to the system with user interaction only.

worm- It is also one type of virus, using this program it will damage your system like virus, not only system it will spread through out the network and checks for honey pot of your os, and enter into the os, it will regrade your system performance and also it will eat your network bandwidth.

Answer 4

Computer worms travel through a network and multiply by themselves.

Viruses are usually restricted to one computer.

Worms usually sneak on by exploiting holes in the software.

Viruses usually working on social deception.

Answer 5

A virus is a piece of code that attaches itself to a program or file so it can spread from computer to computer. A worm, like a virus, is designed to copy itself from one computer to another, but it does so automatically.

Answer 6

Both a virus and worm are types of malware programs that range from very annoying to extremely dangerous. Viruses attach themselves to programs or files, and count on humans to run the program or open the file in order to infect a PC. Worms, a subset of Computer Viruses, are similar to viruses but they do not require any human action to infect a PC and spread throughout a network and even beyond, say by emailing itself to everyone in your address book.

Answer 7

A worm can replicate itself and does not need a host for distribution

Answer 8

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