Разработка управленческих решений в организации

A virus is a "deviant" program that attaches itself to computer systems and destroys or corrupts data.

The virus usually attaches itself to your hard disk. It might then display annoying messages ("Your PC is stoned—legalize marijuana") or cause Ping-Pong balls to bounce around your screen and knock away text. More seri­ously, it might add garbage to or erase your files or destroy your system soft­ware. It may evade your detection and create havoc elsewhere.

Viruses take several forms, the two traditional ones being boot-sector viruses and file viruses. One recent type is the macro virus. There have been many strains of viruses in recent years, some of them quite well known (Stoned, Jerusalem B, Lehigh, Pakistani Brain, Michelan­gelo). Some 6000 viruses have been identified, but only a few hundred of them have been found "in the wild," or in general circulation. Although most are benign, some are intended to be destructive. Some virus writers do it for the intellectual challenge or to relieve boredom, but others do it for revenge, typically against an employer. One virus writer calling himself Hellraiser, who in his pre-computer youth used to roam New York City streets with a can of spray paint, says that "Viruses are the electronic form of graffiti."

The fastest-growing virus in history, many experts say, is the Word Con­cept virus (or simply Concept virus), which worries people because it sneaks past security devices by hitching rides on e-mail and other common Internet files. Concept attaches itself to documents created by Microsoft's popu­lar word processing program, Word 6.0 or higher. A virus called Boza, though not easily spread, specifically s programs on the Windows 95 operating system, corrupting them so they can no longer function.

A virus is a piece of software written deliberately to enter your computer and damage your data. Typically it attaches itself to another program and replicates itself trying to ‘infect’ as many files as possible. Some viruses are polymorphic (e.g. the Tequila mutation). Others are capable of transmitting themselves across the Net.

Here are some types of viruses:

· Logic bomb – a virus which is triggered when a specific program is executed. A timer bomb is activated on a certain day. For example, the Jerusalem virus is activated on Friday 13^th, displaying a black window on the screen and deleting infected files.

· Macro virus – it infects documents run by programs that use macros (e.g. word processors). A typical macro virus is Melissa, which was passed in MS Word files sent via e-mail.

· Worm – is a special type of virus that uses computer networks and security holes to reproduce itself independently, without having to attach itself to another program. A worm called Code Red replicated itself many times in 2001 infecting thousand of Web servers.

· Trojan horse – a destructive program that disguises itself as a safe program. A Trojan horse does not reproduce itself but instead can crash the system or erase the files on your hard drive. The term comes from a Greek legend: the Greeks offered a wooden horse to the Trojans, their enemies. Once the horse was inside the city walls, thе Greek soldiers came out of the horse’s belly and captured Troy.

Viruses can enter your computer system in three different ways:

1) via a disk drive, when you insert infected disks or CDs;

2) via files downloaded from the Web;

3) via e-mail attachments.

When you open an infected file, the virus is activated and installs itself into the computer’s memory. Then it spreads to storage devices and may infect your friends’ system through thee Net. A good example is ILOveYou, an Internet worm released in 2000 as an e-mail attachment (Love-Letter-For-You). When you opened this file, the virus was sent to everyone in your address book.

But there is protection software e.g. Norton Antivirus, McAfee VirusScan) that will help you detect, diagnose and eradicate viruses. Don’t forget that new viruses are created every day, so try to update the database of your anti-virus program regularly.

It is a good idea to make a back-up copy of all your important files. It’s also advisable not to open e-mails from strangers.

 

 

Разработка управленческих решений в организации