In our health-conscious society, viruses of any type are an enemy. Computer viruses are especially pernicious. They can and do strike any unprotected computer system, with results that range from merely annoying to the disastrous, time-consuming and expensive loss of software and data. And with corporations increasingly using computers for enterprise-wide, business-critical computing, the costs of virus-induced down-time are growing along with the threat from viruses themselves. Concern is justified - but unbridled paranoia is not. Just as proper diet, exercise and preventative health care can add years to your life, prudent and cost-effective anti-virus strategies can minimize your exposure to computer viruses.
· A history of computer viruses
· Who writes viruses - and how they can reach you
· The early warning symptoms of virus infection
· The real numbers behind the growth of viruses and their costs · How viruses work - and how virus protection can stop them
What, Exactly, Is A Computer Virus?
A computer virus is a program designed to replicate and spread, generally with the victim being oblivious to its existence. Computer viruses spread by attaching themselves to other programs (e.g., word processors or spreadsheets application files) or to the boot sector of a disk. When an infected file is activated - or executed - or when the computer is started from an infected disk, the virus itself is also executed. Often, it lurks in computer memory, waiting to infect the next program that is activated, or the next disk that is accessed.
What makes viruses dangerous is their ability to perform an event. While some events are harmless (e.g. displaying a message on a certain date) and others annoying (e.g., slowing performance or altering the screen display), some viruses can be catastrophic by damaging files, destroying data and crashing systems.
How Do Infections Spread?
Viruses come from a variety of sources. Because a virus is software code, it can be transmitted along with any legitimate software that enters your environment:
· In a 1991 study of major U.S. and Canadian computer users by the market research firm Dataquest for the National Computer Security Association, most users blamed an infected diskette (87 percent). Forty-three percent of the diskettes responsible for introducing a virus into a corporate computing environment were brought from home.
· Nearly three-quarters (71 percent) of infections occurred in a networked environment, making rapid spread a serious risk. With networking, enterprise computing and inter-organizational communications on the increase, infection during telecommunicating and networking is growing.
· Seven percent said they had acquired their virus while downloading software from an electronic bulletin board service.
· Other sources of infected diskettes included demo disks, diagnostic disks used by service technicians and shrink-wrapped software disks - contributing six percent of reported infections.
What Damage Can Viruses Do To My System?
As mentioned earlier, some viruses are merely annoying, others are disastrous. At the very least, viruses expand file size and slow real-time interaction, hindering performance of your machine. Many virus writers seek only to infect systems, not to damage them - so their viruses do not inflict intentional harm. However, because viruses are often flawed, even benign viruses can inadvertently interact with other software or hardware and slow or stop the system. Other viruses are more dangerous. They can continually modify or destroy data, intercept input/output devices, overwrite files and reformat hard disks.
What Are The Symptoms Of Virus Infection?
Viruses remain free to proliferate only as long as they exist undetected. Accordingly, the most common viruses give off no symptoms of their infection. Anti-virus tools are necessary to identify these infections....