| A virus is a program that copies itself. A trojan is a
virus that does something nasty that you weren't expecting like altering or deleting files
on your hard drive or preventing you from accessing your computer. A worm is a virus that
spreads itself across networks, such as the now infamous email viruses that use an email
address book to send themselves to other computers. Generally, the words trojan and worm
are referred to as viruses though. Viruses can be introduced to a computer thru floppy
disks, downloads from the Internet, and email attachments. The way to reduce exposure to
virus infection is to use these things rationally: - transfer
floppies from machine to machine only if they are known to be virus free; always scan
suspect floppies first with an up-to-date scanner program.
- download software and files from trusted sites and transfer files
thru messaging programs like ICQ and MS Mail from people you know and trust; before
installing, scan with an up-to-date scanner.
- open only those attachments that come from someone you know, and
only if they are expected; avoid receiving junk email by not giving out your email address
online to surveys, contests, freebies, etc. Examine the file extension of all email
attachments you intend to open - do not open anything with a double dot extension (for
example: file.jpg.vbs) as this is common way that viruses disguise themselves as other
file types.
- install and keep up-to-date a good virus scanner program.
Virus scanners are software programs which prevent or clean virus
infection. Starting when your machine boots, a scanner remains in memory and constantly
monitor files as they are opened from your hard drive and floppies. Viruses do not
disguise themselves as just any file type. All files on your computer have extensions or
file endings to indicate their type. Program files have file endings which indicate the
type of environment in which they operate: endings such as .exe, .com, .dll, .sys, and
.386 require the windows operating system environment to execute and run as programs, and
files ending in .vbs, .pif, .js require other operating environments such as MSDOS or
specific scripting engines. Application files, such as those ending in .txt, .gif, .jpg,
and .mov require programs or "viewers" to display them. Because a virus is a
program, it needs access to an operating environment in order to infect and spread, so it
will disguise itself with the same type of file endings as programs. Viruses do not
disguise themselves as application files.
Downloaded files and email attachments are the most common origins
of computer viruses; if they are of the program file type, double clicking on them causes
them to "run". Without an adequate virus scanner running in memory to monitor
this operation you will be infected if the file is a virus. McAfee does this monitoring
very well by scanning program files before they are run, issuing a warning and stopping
machine operation if the file matches known virus code. As new viruses are created and
spread it is important to keep your virus scanner's information (.dat) files up to date.
To perform a scan of a hard or floppy drive, directory, or file,
open the Console, double click Scan Drive C, set the conditions (directory or drive
location) by clicking Edit, configure what you wish to scan, and then clicking OK, then
clicking Run Now.
If You Think You Have a Virus...
Use your machine as little as possible, and avoid using email. Some viruses will even use
your Internet connection without your knowledge, and could send out your personal
information or propagate themselves while you are busy with another computer task.
Performing a scan with an up-to-date virus scanner while Windows is
running will locate viruses that are in files on your hard and floppy drives, but will not
detect those that have been loaded into memory at bootup time. To eliminate these, you
must boot your machine with a floppy in the A: drive containing McAfee Virus Scan. To
obtain such a floppy please contact Computer Services at 566-0552 or 566-0465.
If McAfee detects a virus, it will present you with a notice window
requesting you to make a choices on what to do with it:
STOP - cease what you were trying to do (open the file)
CLEAN - clean the infected file, if suggested
DELETE - delete the infected file, usually after attempting to clean fails
EXCLUDE - ignore the virus warning and continue; the file is flagged and will not be
scanned the next time you try to access it. Useful for files that are false positives, but
be careful with this, as once a file is excluded the scanner will no longer scan it.
Be sure the file does not contain a virus before you opt to exclude it! |
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the VirusScan Console
window appears: 
