Junk Email and Viruses
What is Junk Email?
Most households will be familiar with
promotional material for everything from the current
bargains at the local supermarket to what's on the local
theatre, delivered to you through your letterbox.
The electronic version, commonly known as spam, promotes
well just about everything!
For a few dollars, a spammer can purchase a CD containing
millions of email addresses, then send millions of spam
emails to addresses all over the world. The addresses are
usually "harvested" from web pages posted in
the Internet, but some are supplied by Internet Service
Providers and companies who ask you "logon" in
order to view restricted pages.
What is a Virus?
A virus is malicious code, designed to
corrupt data on your computer, and any other computers it
can find. The code can do anything from playing endless
Barry Manilow songs, to totally wiping all the data on
Typically, viruses are subtler in delivering their
payload. Many recent viruses, such as "SirCam",
take advantage of loopholes in the computer's operating
system or programs. For example, a virus might replicate
itself, attach itself to a document found in a common
storage area, and send itself to every email address
found in the address book of the computer's email program.
That could mean sending you profit and loss spreadsheet
file to all your friends and business associates!
Junk mail, Viruses and
Junk mail and viruses can affect your
speed in a number of ways.
- Downloading data that you didn't
ask for is a waste of bandwidth. If you want to
download a 4MBytes MP3 file while your email
program is busy downloading 2MBytes of junk, your
download time is going to be longer.
- Some viruses read email addresses
from your email program's address book, then send
files (infected by the virus) from your computer
to all those addresses. Thy often have their own
mail engine, so you want have any record of the
files being sent. The "SirCam" virus,
for example, send a 360KBytes version of a file
in the "My Documents" folder to
addresses picked from cached web pages. Cable and
DSL modem users, in particular, may be un-aware
that their computer is constantly sending out
vast amounts of private data.
Avoiding Junk Mail and
Although it is probably impossible to
avoid being hit by a virus, here are some tips to
reducing the risk of infection:
- Use anti-virus software, and
update it regularly. New viruses appear every
day, and can propagate around the world in hours.
- Avoid downloading junk email and
viruses by screening your email before you
download it. Check out my own multi-platform Java
- Don't store important information
in predictable locations. For example, MS Windows
users shouldn't store documents in C:\My
Documents, or Email Addresses in the Outlook or
Outlook Express Address Book. Indeed, you
shouldn't install Anti-Virus software in the
folder suggested by the installation program as
some virus simply delete known anti-virus folders.
If you really want to use the Outlook / Outlook
Express Address Book, include an entry that will
never be delivered (firstname.lastname@example.org) and your
own email address. This way, if a virus does
manage to send a message to every address in your
address book, you'll get a message from yourself
and a warning that an email could not be
- If your email address is published
anywhere on the Internet, expect it to attract
junk mail. Remember that addresses posted to
Newsgroups could also be harvested. Set-up a
separate private account for use by your family,
friends and business associates, allowing you to
change your public address at will.
- Don't open attachments unless you
are sure who they are from and what they contain.
Junk email and virus writers try to trick you
into becoming exposed to their advertising or
- Many junk emails encourage you to
click a link at the bottom of the page in order
to be removed from their mailing lists. Often,
you are simply letting them know that your email
address is valid, and therefore should not be
removed. Also, it may earn them another few cents
from their sponsors. Valid removal links, should
be easily recognisable, and relate to a valid web
page. Beware of links to IP numbers. For example,
http://184.108.40.206 could be anywhere. It would
be relatively easy to copy the homepage and other
pages of the Amaxon.com website, and ask surfers
to go to http://220.127.116.11.78/books/ordering.htm
with their credit card details! And recent
viruses entice you go to a web page, where a
script on the web page delivers a viral payload.
- When sending and replying to
email, send documents as Rich Text Format or
better still plain text, as opposed to Word
documents, which can carry macro viruses.
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© Copyright Leslie Long, 1997-2002