Computer Viruses And Internet Worms Explained

Your computer is slow? Do not open programs and you can not get into something? Well, maybe you have a sick computer. Just as people get sick from the virus, so do computers. When this happens, you will need a computer technician look at the computer to format and get rid of the virus. If you know anything about computers, you may be able to do it yourself.

What is a virus?

A virus is a parasitic program written intentionally to enter a computer without your consent or knowledge. The parasite word is used, because the virus files or boot sectors and replicates itself, allowing it to spread. Though some viruses do nothing but replicate itself, others can cause serious damage or affect program and system performance. The virus should never be assumed harmless and left the system.

Viruses

Viruses are classified by how they infect computer systems:

1) Programme. As executable files that end with a COM, EXE, OVL, DRV Bin System .....

2) Boot: Boot Record, Master Boot, FAT and Partition Table.

3) Multi: Both program and boot infector.

What is the Trojan horse?

Besides being a large wooden horse used in the Trojan war 2500 years ago (and more recently by Brad Pitt), a Trojan or Trojan Horse is a computer program that seems trivial or harmless, but conceals a further additional function bad. In general, a Trojan is a part of the program on your computer from an external source - (Internet downloads, such as a diskette, CD, email infected). Trojans can sometimes be dangerous. For example, a computer program may seem a demo of a game, but at the same time enjoy the game, you may be happy to reformat your hard disk or by email to all the porn sites in your e-book addresses.

The Trojans also used the "back door", or "floor" to sneak the computer's operating system information. An example is a program that pretends to be a registry of the program (as you can see, Windows NT / XP or Linux). When the unsuspecting user tries to access a Trojan program used to store the user name and password. Then you can indicate a failed attempt to log in and log out on the actual program. The user can successfully access the system the next time, but this time a Trojan has received enough information to access the system.

Example Trojans

Notroj. This Trojan pretends to be a program that protects against the Trojans. It is actually a time bomb that erases the hard disk after more than 70 percent complete.

Pwsteal.refest A trojan that installs as a BHO (Browser Helper Object) for Internet Explorer and steals online banking information when presented in web forms.

PWSteal.Likmet.AA Trojan horse that displays a fake login window of MSN Messenger and steals the password available.

Run.me. This is a graphics program that plays the national anthem and display the U.S. flag while dragging on the hard drive and deletes the data it contains.

What worm?

Worm is a program of self-propagating that works its way through the system or network (eg the Internet), often cause damage. It does not require a host program to activate it. Someone has to add the worms directly into the network between the computers, which can be sent from one another, and the files and programs have changed. An example of a local network, where each computer has its own files, programs, operating systems and hard drives, as would be found in a university or corporate environment.

Example of Worms

Worm recovery. A worm that reaches out across the network to an output terminal (the one with a modem) and place the heels of a list of users.

vigilante worm. A special program that automatically takes measures to limit the size of a worm, on or off, it grows beyond a certain limit. The worm also has a changing of the guard ran the registry entry