What is a Computer Virus?
By Alex Kubik
A computer virus is a malicious computer program that, when
executed by an unsuspecting human, performs tasks that primarily include
replicating itself and in some cases deploying a payload.
A decade or so ago, viruses were pretty simple. They got into a system
and infected a file or two. It was a basic as ordering coffee when coffee
was easy to order. "One coffee pleaseblack."
Today, the catalog of viruses you have to defend yourself against is frighteningly
complex. In fact, it's become as complex as, well, ordering coffee.
"Looks like you've been infected by a dropper that's put a Trojan
on your system, which deployed a multi-partite that opened a backdoor and
also infected the master boot record."
Sounds like an order at Starbucks, don't you think?
These days a discussion about a virus can actually occur without using
the word virus because sometimes viruses are worms or Trojan horses, which
are virus-like nasties that act a little different than their infectious
cousins.
Why are they called computer viruses? Well, because they have similar characteristics
to biological viruses that infect humansin at least one way. The computer
variety jumps from computer to computer much like a cold virus jumps from
your kids to you and from you to your spouse.
Don't let all this frighten you, though. It's not that hard to figure out
and defending your computer against viruses is pretty straightforward.
Still, if the idea makes you queasy, skip ahead to the part of the chapter
about how to easily protect yourself from viruses. But I hope you stick
around because the more you know, the geekier you will be. Okay, not really.
But understanding them makes them much less scary.
Viruses were one of the first real security threats people had to deal
with when personal computers started appearing in homes a couple of decades
ago. The first computer viruses were written in the 1980s; however, they
really didn't become a big threat until the late 1990s when everyone who
owned a personal computer started connecting to the Internet.
Before then viruses spread via floppy disks or CDs. They would ride on
the back of files stored on a disk or in the boot area of the floppy and
replicate when the disk was inserted into the computer.
The Internet's popularity has also become the chief reason that security on personal computers has become such a hot topic. A Net connection is the off-ramp from the Internet into your computer for all data. And guess what? For viruses it's an express lane.
