Computer Viruses
By Joy Stapleton
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What are computer viruses, how are they created, and how are they different from other programs?
A virus is a malicious program that attaches itself to other programs. Programs that are capable of replicating themselves and
spreading throughout the machine are considered viruses. When the original program that the virus program is attached to is
executed, the virus program is also executed. The virus will continue replicating itself by attaching itself to other programs.
A Trojan horse program is a malicious program that hides itself inside another program. When this program is executed the Trojan
horse program will also execute and perform whatever task it was designed to do.
Trojan horse programs are typically used to allow a hacker to gain remote access to your computer in order to collect data from
your hard drive, such as credit card information, other personal information, and passwords. Often a Trojan program will change
the system registry to include a line to launch itself whenever Windows boots up.
Then there's the worm, that doesn't attach itself to other programs, but it can spread its damage far and wide by attaching
itself to email files and sending a copy of itself to everyone in the victim's address book. The person on the receiving end will
often download and execute the attached file thinking that it was sent to them by a friend.
The worm will usually wreak havoc by deleting specific files, critical system files, or entire folders by using typical
programming commands that were designed for the purpose of maintaining computer systems. It doesn't take a genius to do this,
just a devious person.
A good anti-virus program will be able to detect all of the known viruses, and the different types of viruses, and eradicate them
from your system if you've been infected. The principle of detecting the virus is basically a matter of examining the program for
its content, and then scanning computer files for that particular content.
I highly recommend using the AVG anti-virus software. They have an excellent FREE version that, in my opinion, out performs the
more well-known commercial programs, McAfee and Norton. However, my highest recommendation would be to purchase the AVG Internet
Security software which includes a firewall and identity theft protection, because it packs a mighty powerful punch. It's well
worth the $54.99 a year.
Both programs are available at AVG Software.
Joy Stapleton started out as a mainframe Programmer/Analyst in 1985. In 1992 she became a PC software developer and PC technician. As a private consultant, Joy provides PC technical services and develops Web sites.


