Virus

Many people don’t understand exactly what a virus actually is.

People don’t know, and more importantly usually do not want to know what the difference is between a Trojan, a worm, a backdoor worm etc.

In short, the term virus simply means a program that replicates and propagates itself. But what does that actually mean? Well computer users are so used to ‘programs’ being these huge complicated things that are installed from a CD and copy hundreds of files the hard disk, and make numerous entries to various registry and system files, that they often do not realise that a ‘program’ can actually be just one or two tiny files. A virus is just that, a tiny ‘program’, with a few lines of code that usually take advantage of OTHER programs on the computer in order to do their dirty-work, and with some built-in feature that causes either self-replication or propagation by some other method.

What Are The Biggest Concerns?

Some viruses are relatively harmless, and can actually be quite amusing, whereas others are designed simply to destroy a system. Fortunately the most destructive types have more or less been dealt with by operating system manufacturers updating their systems and blocking the way somewhat.

But it is important to note that although some protection is in place on an up to date system, always remember that to delete all your documents only requires a single confirmation, one hasty press of the enter key, and how many time have you answered ‘yes’ to a message box without actually reading the question properly?

It is easy to see therefore how simple it is to create havoc on a less up to date system. In actual fact these days the ‘delete files’ types of attack are quite rare. More often now we are confronted with either Denial Of Service (DOS) attacks or some form of Spyware or information gathering virus. DOS attacks range vastly from the very well planned virus that spreads undetected to thousands of computers with the intention of them all performing some function at the same time. These are usually directed towards the bigger companies like Microsoft, but obviously also tie up resources on all the infected computers. Other DOS attacks work locally to prevent you from sending mail or connecting to the Internet, or maybe even from running the system at all. Information gathering viruses can record keystrokes, passwords etc, and forward them on to the virus-writer, or in some cases even publicise your private information. Some viruses can sit idly and undetected on your system until the virus writer decides to employ YOUR computer to do something, and can gain access to run programs, download files, send spam etc.

How do they infect computers?

Viruses are spread to other computers by using clever methods to trick users into downloading or opening a file that contains the virus infecting the users computer.

An example of a quite threatening email follows. This was actually sent to one of our staff:

Sub: You visit illegal website's
Date: Wed, 23 Nov 2005 09:54:04 UTC
From: Mail@cia.gov
----------------------------------------------------------------
Dear Sir/Madam, we have logged your IP-address on more than 30 illegal Website's. Important: Please answer our questions! The list of questions are attached. Yours faithfully, Steven Allison ++++ Central Intelligence Agency -CIA- ++++ Office of Public Affairs ++++ Washington, D.C. 20505 ++++ phone: (703) 482-0623 ++++ 7:00 a.m. to 5:00 p.m., US Eastern time list.zip

This email was designed to spread fear and cause panic to those who receive it. First of all the user is accused of visiting illegal website's, even if they knows this to be false they may still be worried about the nature of the email as it refers to the CIA and Washington DC. They are then prompted to answer questions and to do this they must open the file called list.zip. The virus is hidden inside the zip file to avoid virus scanners removing it from your email. One the user opens the file the virus is installed usually without the users knowledge or consent. The virus is then free to do what it was programmed for, which in most cases is to use your internet connection to mass email the virus on to other users including those stored in your email contacts thus continuing the life span of the virus.

Do not rely on virus scanning software to clean up your inbox. Although it is advised to have security software they can not stop every virus that appears and tries exploits human weakness in the system. The best prevention for infection is knowledge and a little common sense.

When you receive a dodgy email ask yourself what is it trying to get you to do, in most cases it will be to open an infected file. If this is the case them just delete it immediately. If however if it was sent by someone you know then email them back and ask them if they really sent it. Its better to be safe than sorry.

Lastly use your common sense. In the case of the example mail above the member of staff lives in the UK so why would the CIA want to ask him questions, surely it would be the UK police.

Not all viruses hide away in a dark corner

Some are blatantly attached to programs that are distributed and run by people who believe they are doing something completely different.You may receive a patch or a game from a trusted friend, install it and forget it and you may never be any the wiser.

All in all viruses do cost this country a HUGE amount in lost productivity, are annoying and frustrating and can be dangerous. People are often indifferent about them because they lack understanding, and often do not act until it’s too late and their security has already been compromised, system corrupted or data lost.

Recovery

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