What is a virus?A virus is a piece of programming code usually disguised
as something else that causes some unexpected and usually undesirable
event. A virus is often designed so that it is automatically spread to
other computer users. Viruses can be transmitted as attachments to an
e-mail note, as downloads, or be present on a diskette or CD. The source
of the e-mail note, downloaded file, or diskette you've received is often
unaware of the virus. Some viruses wreak their effect as soon as their
code is executed; other viruses lie dormant until circumstances cause
their code to be executed by the computer. Some viruses are playful in
intent and effect ('Happy Birthday, Ludwig!') and some can be
quite harmful, erasing data or causing your hard disk to require reformatting
(searchSecurity.com).
What classes of viruses?
File infectors. Some file infector viruses attach themselves
to program files, usually selected .COM or .EXE files. Some can infect
any program for which execution is requested, including .SYS, .OVL, .PRG,
and .MNU files. When the program is loaded, the virus is loaded as well.
Other file infector viruses arrive as wholly-contained programs or scripts
sent as an attachment to an e-mail note.
System or boot-record infectors. These viruses infect
executable code found in certain system areas on a disk. They attach to
the DOS boot sector on diskettes or the Master Boot Record on hard disks.
A typical scenario (familiar to the author) is to receive a diskette from
an innocent source that contains a boot disk virus. When your operating
system is running, files on the diskette can be read without triggering
the boot disk virus. However, if you leave the diskette in the drive,
and then turn the computer off or reload the operating system, the computer
will look first in your A drive, find the diskette with its boot disk
virus, load it, and make it temporarily impossible to use your hard disk.
(Allow several days for recovery.) This is why you should make sure you
have a bootable floppy.
Macro viruses. These are among the most common viruses,
and they tend to do the least damage. Macro viruses infect your Microsoft
Word application and typically insert unwanted words or phrases.
The best protection against a virus is to know the origin
of each program or file you load into your computer or open from your
e-mail program. Since this is difficult, you can buy anti-virus software
that can screen e-mail attachments and also check all of your files periodically
and remove any viruses that are found. From time to time, you may get
an e-mail message warning of a new virus. Unless the warning is from a
source you recognize, chances are good that the warning is a virus hoax.
What can a virus do to my computer?
There are many things from wiping out your entire hard
drive(all information on your computer) to annoying you while word-processing
by bold-facing or italicizing lines at random to causing trouble when
trying to print. The list is almost endless.
What can a virus do to my computer?
There are many things from wiping out your entire hard
drive(all information on your computer) to annoying you while word-processing
by bold-facing or italicizing lines at random to causing trouble when
trying to print. The list is almost endless.
Why should I be concerned about viruses?
Because they do damage to your files and you can spread
them to other computers which will then be damaged.
How do email attachments relate to viruses?
Email attachments are currently the most common way in which viruses are transmitted. If you receive an email attachment who's
name ends with .(exe hta pif vbs vbe jse cmd vxd scr lnk chm shm xls.com
doc.com doc.bat xls.bat exe.pif zip.com) etc, beware of it. It may be
harmful. Always check with the person who sent it before opening it and
if you are not 110% sure, never open any attachment.
How do I know if my computer is infected with a virus?
You will see symptoms such as frequent crashing, programs
that worked that now do not, files becoming damaged or disappearing. If
you use MS-Word, you can see things happening like sections of text being
bold-faced or italicized at random, a window that pops up calling you
rude names, printing doesn't seem to work quite right. All of these are
symptoms. There are others. In general, look for something that seems
to be highly irregular.
How do I get rid of a virus if I am infected?
You will need to have a virus scanner installed on your computer in order to remove viruses. Many of you already have such a scanner
on your computer. You will need to keep it updated as much as possible.
What can I do to keep from getting infected?
Use a scanner such as McAfee or Norton which comes equipped with a Virus Shield. This software device will detect viruses as they
try to get into your system and alert you.
Where can I find information on the latest viruses?
Try any of the following web sites:
McAfee.com
Symantec.com
Vaksin.com
Antivirus.com
Trendmicro.com
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