|
Most malevolent software won't infect
your machine unless you open an e-mail attachment. So virus distributors
use various tricks, which experts call "social engineering," to
con you into clicking. A common way to draw you in is to have the e-mail
come from a family member or friend.
These illustrations show other basic types of tricks that have been
used by well-known viruses and worms. Antidotes were developed for all of
them. If you receive messages like these, delete them and run a virus check
before doing anything else with the computer.
THE INFECTED DOCUMENT
 Here, the subject line includes the name
of the sender, probably someone you know. The message itself tempts you to
open the attached Microsoft Word document ("don't show to anyone
else"). The attachment is a legitimate Word file--but infected with a
macro, an invisible, embedded program that runs when Word opens the
document.
THE MISLEADING FILE NAME
 If you aren't familiar with the way
Windows names files, you can easily mistake the attachment's name,
"LOVE-LETTER-FOR-YOU.TXT.vbs," for that of a harmless text file.
In fact, the file's "vbs" suffix is the real one, which
identifies it as a type of program known as a Windows script--a rudimentary
computer program that an intruder writes to run on your Windows operating
system. The suffix may be hidden entirely on your computer, thus appearing
to be a type of file you'd willingly open, such as a JPEG image, MP3 music,
or PDF document.
THE OFFER YOU CAN'T
REFUSE
 This example relies on a message so
compelling--an offer to rid your computer of a virus--that it doesn't need
to disguise the fact that the attachment is a program. Unfortunately, the
program is a worm that sends itself to e-mail addresses it finds on your
computer.
THE FAKE WEB LINK
 This example uses several tricks. The
subject and message suggest that opening the attachment will take you to a
web page containing party photos. The attachment's name resembles a web
address, but there's no web site involved. This is actually a program that
sends itself to your friends and colleagues. This particular intrusion was
designed to tie up your e-mail; it could easily have been designed to
destroy data.
|
