Posted on 9-8-2002
Viruses-
Know Your Enemy
What is a virus?
A virus is any computer program that can "self-replicate" or
make copies of
itself and spread itself from one machine to another without
the help of
the user.
Viruses are often programmed to carry out other actions separate
from
replication. These actions, or payloads, vary from the annoying
(altering a
computer's homepage) to the damaging (deleting files). Because
viruses are
computer programs, they can do anything a normal program can
do, including
deleting files, formatting hard drives, and overwriting the
BIOS. But
though many viruses do carry such payloads, a program does not
need to have
a payload in order to be considered a virus. Some viruses do
nothing at all.
How do viruses spread?
Viruses can be spread via floppy disks or CDs, email attachments,
or in
material downloaded from the Web, although the majority of viruses
that are
currently a threat are spread by email. These viruses are usually
hidden
inside of attachments emailed to computer users, and the emails
are usually
labeled with intriguing subject lines -- "I Love You" or "Anna
Kournikova
Naked" -- designed to tempt users into opening them. When the
attachment is
opened, the virus is activated, and the user's computer becomes
infected.
Often, viruses are programmed to spread themselves by emailing
a copy of
the attachment in which they're hidden to all the other email
addresses in
an infected computer's address book. So once your computer is
infected, all
your friends and contacts are at risk as well.
How do I avoid getting a virus?
The best way to avoid getting a computer virus is to never open
attachments. Since most viruses are spread via email attachments,
refusing
to open such attachments will keep you from getting many viruses.
If you must open an attachment, contact the person who sent
you the
attachment to make sure they sent it. Because viruses often
spread
themselves via an infected computer's address book, emails from
people you
know aren't automatically safe.
Also, check the type of attachment before opening it. Attachments
that end
with the .vbs extension (Visual Basic script) or the .exe extension
(program files) pose a real danger and are often how viruses
are spread.
However, any attachment with any extension after the dot can
still contain
a virus.
Finally, make sure to install and update antivirus software.
Companies such
as Norton, Symantec, and McAfee offer many kinds of antivirus
programs,
some of which are downloadable from the companies' websites.
You can use
this software to scan attachments for viruses before you open
them.
You can also run an antivirus program that utilizes "on-access"
scanning.
This type of scanning takes place constantly, automatically
checking every
file, program, or document every time it is opened or used.
How does antivirus software work?
Antivirus software keeps a database of "fingerprints" -- a set
of
characteristic bytes from known viruses -- on file. It searches
files and
programs on your computer for that pattern, and when it finds
a fingerprint
it recognizes as belonging to a virus, the antivirus software
notifies the
user that that virus is present. There are also heuristic programs
that
look for virus-like behavior in programs, allowing the software
to detect
completely new viruses.
Antivirus software needs to be updated regularly so that it
can search a
computer for new viruses. Be sure to check with the company
that produces
your antivirus software package for periodic updates.
What do I do if I suspect my computer has become infected?
There could be many reasons for your computer to act strangely.
If you
think your computer may have a virus, the first thing you should
do is find
out for sure by running a virus scan of your machine. If you
have antivirus
software, have it search your computer for the latest viruses.
If you do
not have such software, many antivirus companies, including
Symantec and
McAfee, offer free virus scans on their websites.
Once you know for sure which virus you're dealing with, you
can find a
removal tool for that specific virus on some of these antivirus
sites.
Follow the instructions on the site carefully. Afterward, you
may have to
repair whatever the virus did.
It may also be a good idea to disconnect your computer from
the Web or from
your network once you realize it has been infected in order
to keep the
virus from sending itself to other machines via your email.
Then run the
virus check before re-connecting.
I Want Antivirus Software - Usual Problem, Which One To Choose?
Try this link for rating of software:
http://www.cnet.com/software/0,10000,0-806174-8-20096702-1,00.html?tag=st.cn
..sr1.ssr
$#%@& Klez
Speaking of viruses and worms, did you know that the Klez worm
is the most
common malicious code on the Internet? It spreads through email
and it's
easy to become an unwitting carrier, spreading it to everyone
in your
Windows address book! Have you received emails with titles like
"a special
humour game" or "a powful tool" or "spice girls vocal concert"
(to name
just a few variations)? If so, then you've been hit by the Klez
worm. This
helpful site will help you determine if you've been hit by Klez,
and what
to if your computer is infected. Go to
http://antivirus.miningco.com/library/blklez.htm
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