Anti Virus Software - It's NOT 100%
Ever get a virus? And no, we're not talking about the kind you
get from the kid down the street sneezing all over you. We're
talking about the kind you get when your computer runs into some
nasty vindictive hackers. These are people who have nothing
better to do with their time but make other people's lives
miserable. If you've ever been attacked by one of these things
you know what I mean.
Enter the anti virus software. In short what this software does
is detect a virus either on your computer or one that is
threatening to slice your PC into little bits and bytes. The
most popular anti virus software companies are McAfee and Norton
Anti Virus, the latter actually owned by Symantec. There are
other companies and now even some ISPs like AOL are providing
anti virus software. But McAfee and Norton are still the kings
of the industry. Before you can understand how anti virus works
you have to understand how the virus itself works and how it
infects your computer.
Contrary to what people believe there are other ways to get a
computer virus other than to open an attachment in an email,
though that is the most common way. Email virus infections occur
when the user opens up an email with an attachment and downloads
the attachment to the hard drive of the PC. What happens from
there can vary greatly but in general what happens is the
attachment, which is usually an EXE file, when saved, releases
some code that performs an action on your computer. This can be
anything from getting private information such as passwords and
credit card numbers and transmitting it to the sender of the
email to simply wiping out your hard drive to the point where it
is beyond repair. There are debates as to which is worse.
Another way to get a virus, and this is the scarier one, is to
go to a web site who's server has been infected with a virus.
This virus can be passed along through the Internet connection
and place a dangerous file on your hard drive. Again, the
actions taken afterward by the virus can be just about anything.
So what exactly does anti virus software do about this? In
simple layman's terms the anti virus software detects the
intruding file and tries to do several things in this order.
First it tries to delete the file before it can ever even get
saved to your hard drive. If it is successful, it is as if the
file never existed and no harm is done. Second, if it can't
delete the file it tries to repair it, if it is a file that is
actually yours to begin with and has been modified by the virus
itself. If it can repair the file again it is as if nothing
happened.
Third, if it can't repair the file then as a last resort it
places the file in quarantine so that it can't infect any other
files. Yes, viruses can spread. In this case some harm may have
been done and you may have to replace the file that has been
infected with a new copy. Sometimes this requires reinstalling
the software the file came from. Other times the file is simply
lost, especially if it is a user created file, though it may be
possible to recreate the file depending on what kind of data it
contained.
So how does anti virus software detect viruses? To put it
simply, your anti virus software has a list of known viruses. It
scans every file that you download to your PC and checks it
against this list. If it finds a match it warns you of the virus
giving you the name of it and then attempts to go through the
steps I've outlined above.
So where does this list come from? Well, that's the hard part
and the reason that anti virus software can never be 100%. The
list comes from known viruses that the software company has
either come in contact with itself or viruses sent to them from
users who have been attacked. Therein lies the less than 100%
effectiveness of anti virus software. There is always a chance
that you will be the first one attacked by a new virus. You
won't know it until something goes wrong with your computer and
then after you report the problem to Norton or McAfee they will
have you send them the file you think caused the problem and run
tests on it. No, it's not an exact science but it's the best we
have.
So since anti virus is not a sure fire prevention the best
prevention is not to download attachments when you have no idea
who sent them to you, make sure your OS has the latest patches
and be very careful about what web sites you go to.
At least you don't have to drink your mother's chicken soup.