Web Pushing Essay

Lecture: Colm Manning
Subject: Web Pulishing
Name: Jesse bumba












Web Publishing
Essay



1. Introduction
2. What are computer viruses?
3. Why computer viruses are called virus
4. Where viruses come from?
5. Who writes viruses?
6. Why they create
7. How virus can reach your computer
8. How viruses infect a computer
9. How viruses spread
10. Types of Computer Viruses
11. Recovery methods
11.1 System Restore
11.2 Operating System Reinstallation
12. Preventive Action
13. Summary




1. Introduction

Networking Technology is perhaps the most significant change agent in the world today, as it helps to create a world in which national borders, geographic distances, and physical limitations become less relevant, and present ever-diminishing obstacles. The creation of online communities for the exchange of ideas and information has the potential to increase productivity opportunities across the globe. As the Internet connects people and promotes unfettered communication, it presents the platform on which to run businesses, to address emergencies, to inform individuals, and to support education, science, and government. This growth however, has not come without a price. With the advent of the Information technology, a new methodology in crime has been created. Electronic crime has been responsible for some of the most financially devastating victimizations in society. Computer virus is the agent behind whole those scenes.

2. What are computer viruses?
A computer virus is a simple set of computer instructions or code that is written by some unscrupulous person. This code is attached to some part of the normal computer operating system or computer program. Instructions in this code tell the computer to perform some task. This task is often destructive, such as deleting important information or crashing the hard disk.

3. Why computer viruses are called virus
The word virus comes from Latin and literally means 'poison' and that is basically what it is a poison able to reproduce itself within another cell or body.
Computer viruses are called viruses because they share some of the traits of biological viruses. A computer virus passes from computer to computer like a biological virus passes from person to person.

4. Where viruses come from?
The first PC virus in the wild was a boot sector virus called Brain, created in 1986 by the Farooq Alvi Brothers, operating out of Lahore, Pakistan. The brothers reportedly created the virus to detect pirated copies of software they had written.

5. Who writes viruses?
Computer viruses are created by professional computer programmer they write the code , test it to make sure it spreads properly and then release it.
6. Why they create
This can not be answered simply, as there are many explanations and reasons for all of these. There are a number of different reasons as to why virus writers create these viruses. Some of them are research projects, pranks, vandalism, to attack the products of certain companies, to distribute political messages, for financial gain from identity theft, spyware, and cryptoviral extortion. However there are also some viruses that are intended to be good, as they help in improvement to the programs. It should also be known and remembered that a poorly-written good virus can still turn bad, as it may misidentify its target file and then result in deleting an innocent system file by mistake.

7. How virus can reach your computer
Prior to the 1980s, computers were rare and they were locked away for use by expert. During the 1980s computers started to spread to businesses and homes because of popularity personal computers were widespread in businesses, homes and college corpuses. That time most viruses were spread on removable media, particularly floppy disks. Many users regularly exchanged information and programs on floppies. Some viruses spread by infecting programs stored on these disks, while others installed themselves into the disk boot sector, ensuring that they would be run when the user booted the computer from the disk, usually inadvertently. PCs of the era would attempt to boot first from a floppy if one had been left in the drive. This was the most successful infection strategy until.
With the widespread of computer network and internet reaching cities, town, countries and continents viruses can reach your computer through e-mail, messenger and attached document.


8. How viruses infect a computer
In order to infect a computer, virus replicate itself and virus must be permitted to execute code and write to memory. For this reason, many viruses attach themselves to executable files that may be part of legitimate programs. If a user tries to start an infected program, the virus' code may be executed first. Viruses can be divided into two types, on the basis of their behavior when they are executed.
Nonresident viruses immediately search for other hosts that can be infected, infect these targets, and finally transfer control to the application program they infected.
Resident viruses do not search for hosts when they are started. Instead, a resident virus loads itself into memory on execution and transfers control to the host program. The virus stays active in the background and infects new hosts when those files are accessed by other programs or the operating system itself.
Once in memory, one of a number of things can happen. The virus may be programmed to attach to other applications, disks or folders. It may infect a network if given the opportunity.
Viruses behave in different ways. Some viruses stay active only when the application it is part of is running. Turn the computer off and the virus is inactive. Other viruses will operate every time you turn on your computer after infecting a system file or network.

9. How viruses spread
Viruses begin to work and spread when you start up the program or application of which the virus is present. For example, a word processing program that contains a virus will place the virus in memory every time the word processing program is run.
Once in memory, one of a number of things can happen. The virus may be programmed to attach to other applications, disks or folders. It may infect a network if given the opportunity.
Viruses behave in different ways. Some viruses stay active only when the application it is part of is running. Turn the computer off and the virus is inactive. Other viruses will operate every time you turn on your computer after infecting a system file or network.
The other way that Viruses can spread is by attachments in e-mail messages or instant messaging messages and also through downloads on the Internet. They can be hidden in illicit software or other files or programs you might download.


10. Types of Computer Viruses
There are different forms of viruses the most common types are;
• Viruses – is a small piece of software that piggybacks on real programs.
• E-mail viruses – it travel as an attachment to e-mail messages, and usually replicates itself by automatically mailing itself to dozens of people in the victim’s e-mail address book
• Trojan horses – is simply a computer program that claims to do one thing ex it may claim to be a game but instead does damage when you run it.
• Worms – is a small piece of software that uses computer networks and security holes to replicates itself.
• Adware- puts ads up on your screen
• Spyware – collects personal information about you like your passwords or other information.
• Hijackers-turn your computer into a zombie computer.
• Dialers- forces your computer to make phone calls.

11. Recovery methods
There are a number of recovery options that exist after a computer has a virus. These actions depend on severity of the type of virus.
11.1 System Restore
One possibility on Windows Me, Windows XP and Windows Vista is a tool known as System Restore, which restores the registry and critical system files to a previous checkpoint. Often a virus will cause a system to hang, and a subsequent hard reboot will render a system restore point from the same day corrupt. Restore points from previous days should work provided the virus is not designed to corrupt the restore files or also exists in previous restore points. Some viruses, however, disable system restore and other important tools such as Task Manager and Command Prompt. An example of a virus that does this is CiaDoor.
Administrators have the option to disable such tools from limited users for various reasons. The virus modifies the registry to do the same, except, when the Administrator is controlling the computer, it blocks all users from accessing the tools. When an infected tool activates it gives the message "Task Manager has been disabled by your administrator.", even if the user trying to open the program is the administrator.
11.2 Operating system reinstallation
Reinstalling the operating system is another approach to virus removal. It involves simply reformatting the OS partition and installing the OS from its original media, or imaging the partition with a clean backup image taken with Ghost or Acronis for example.
12. Preventive Action
1. Load only software from original disks or CD's. Pirated or copied software is always a risk for a virus.
2. Execute only programs of which you are familiar as to their origin. Programs sent by email should always be suspicious.
3. Computer uploads and "system configuration" changes should always be performed by the person who is responsible for the computer. Password protection should be employed.
4. Check all shareware and free programs downloaded from on-line services with a virus checking program.
5. Purchase a virus program that runs as you boot or work your computer. Up-date it frequently.


13. Summary
To help avoid viruses, it's essential that you keep your computer current with the latest updates and antivirus tools, stay informed about recent threats, and that you follow a few basic rules when you surf the Internet, download files, and open attachments the ones who know the source. You never open e-mail attachments unless you know who it's from and you are expecting it and Backup all your important files scan your computer time to time.