A virus is a piece of software code that, like a biological virus, makes copies of itself and spreads by attaching itself to a host, often damaging the host in the process. The host is your computer’s operating system. The virus then infects files that are transferred to other computers. Viruses use the host's resources (memory and hard disk space) and are sometimes deliberately destructive (erasing files or formatting hard disks). Many of the more sophisticated viruses do minimal direct harm but are designed specifically to allow others to access your machine without authorization.
While viruses are often malicious, some are fairly benign or merely annoying (for example, playing a message on a specific holiday or day of the month. Their uncontrolled self-reproduction wastes or overwhelms computer resources. "Good" viruses sometimes appear that are intended to spread improvements or to delete other viruses. Unfortunately, "good" viruses are quite rare, still consume system resources and may accidentally damage the systems they infect.
"Virus" is often used to describe all kinds of malware (malicious software), including those that are more properly classified as worms or trojans. Most popular anti-viral software packages defend against all of these types of attack.
- A virus must attach itself to another program to function.
- A worm is a self-contained program.
- A trojan is also a self-contained program, but unlike a worm which can send itself to other computers, a trojan must be loaded by an unsuspecting victim - usually by masquerading as an innocent download file or email attachment with a name like README.txt.exe.
Westfield Group protects our office computers by installing current anti-virus software on all computers, establishing firewalls at the computer access points and filtering all e-mails for malicious content. To help protect your system from viruses, worms and trojans:
- Never load a disk or file to your computer unless you know and trust the source.
- Never disable the anti-virus software even temporarily.
- Do not post your company e-mail address on a website or chat board. (Hackers frequently troll through those sites looking for target accounts.)
- Install anti-virus and firewall software on your computer and keep it current.