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Viruses | Outside
Resources
Definition:
A virus is a program whose purpose is to reproduce itself through
means of a computer without the knowledge of the user(s). Viruses
are generally always malicious in nature, and can do anything from
annoy users to destroy files. Viruses are not spontaneous creations
of computers; they are written by people, for all the same reasons
that people would want to annoy others in more traditional manners.
The main purpose of a computer virus (like a biological one) is
to duplicate itself. The results of this duplication tend to far
outweigh the results of other damage it may cause. The duplication
of viruses usually occurs through sending e-mail, which can clog
networks to the point of crashes. Even if the virus has no other
attack methods, it's using computer cycles that otherwise would
not have been used, and without your permission.
How you would get them:
Viruses tend to come attached to files which can execute code. This
includes actual programs (usually ending in ".exe"), and
files which contains script languages that can be run within other
programs (such as Microsoft Word documents, or ".bat"
or ".pif" files; they may also be embedded in ".zip"
files). These viruses can begin executing their code in a variety
of ways. They may start up immediately upon downloading and opening.
Others may trigger when the clock reaches a certain date and/or
time.
The majority of people obtain these files downloading them as attachments
from e-mail.
How to recognize a virus - On the web:
Many viruses may masquerade as other programs, such as games, or
other "freeware." If you are not sure about the authority
or credibility of the site you would download said program from,
your best bet is to not download from there at all. Or, use anti-virus
software to scan a download before opening.
How to recognize a virus - In e-mail:
Viruses are generally "sent" by people you know, which
may at first seem confusing. However, there are many indications
that the e-mail contains a virus.
The first step is to look at the subject heading. Most viruses
that send themselves via e-mail contain poorly worded subjects (with
lots of capital letters in grammatically incorrect sentences). Be
suspicious of poorly-worded or -spelled subject lines from people
you know, in particular.
If you have a message with an attachment in your inbox from someone
you know, and they have not previously told you that they will be
sending it, you should ask them if they know they have sent you
such a message by sending them an e-mail before you open the e-mail
of the attachment.
If you are using Microsoft Outlook Express as an e-mail client,
click to highlight the message in question, and then click the right
mouse button to bring up a menu. Choose "Properties,"
and click the "Details" tab. By clicking "Message
Source" in this area, you will be able to look back and see
exactly who the e-mail is coming from without opening it; it's like
peeking inside a sealed envelope. Look for something along the lines
of "<iframe" . . . >"; this is the code that
triggers the virus in Outlook-specific emails. By not even opening
the mail, you have potentially saved yourself from further getting
involved with a potential virus. If you see <iframe>, delete
the mail.
On the other hand, if you receive a message with an attachment
from someone you don't know, your best bet is to simply delete the
message and be done with it. You can always use the above trick
to "peek" inside the message first.
Anti-virus programs:
The most common method for dealing with viruses is the use of anti-virus
programs. These programs actively "seek and destroy" viruses
on your computers, and can be updated as often as you wish (to add
new viruses to their master list). Generally, these programs will
also scan each new file as it is downloaded, to be sure nothing
is infected. You can scan a hard drive, a floppy disk, etc. for
viruses before anything is even opened from them! This is a great
help in keeping viruses off of your computer.
Two of the most well-known (and proven effective) are Norton (www.symantec.com/nav)
and McAfee (http://us.mcafee.com/). Both offer their own anti-virus
programs at a reasonable rate, and offer almost daily downloads
and upgrades. For these programs to work, however, you MUST download
upgrades and patches on a regular basis (these are available on
the companies' respective websites).
Other Measures:
- Turn off the preview pane in Outlook Express. The preview pane
shows a message before you open it. Emails with code like <iframe>
will execute in the preview pane before you can delete them. To
turn off the preview pane, go to your inbox and click View >>
Layout and uncheck "Preview Pane."
- Switch e-mail clients. Outlook Express is a popular program
for e-mail. It's also the most vulnerable for viruses. Consider
switching to other free programs such as Netscape
Messenger or Eudora.
Alternatively, check for updates and patches for Outlook at: http://www.microsoft.com/windows/ie/downloads/critical/default.asp
- Quarantine floppies. Public computers used by multiple users
(such as in computer labs) often contain viruses. Designate one
floppy to be used on public computers, and scan for viruses before
transferring files to your home computer.
Not a virus?:
Not all data corruption may be the fault of a virus. Just like any
other appliance, computers begin to wear down over time. It may
be a sudden thing, but more than likely, it will be a gradual downward
spiral. If you find data being corrupted, yet anti-virus software
finds no problems, you may want to look into checking your hardware
for problems.
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