A. Viruses
are generally small programs that get into the computer system and
are activated in a variety of ways. Most viruses are transferred
via
e-mails. They are included as attachments which, when opened, infect
the computer, generally without the knowledge of the user. Some do
nothing except multiply and infect other computers, some create visual
effects or alter the computer system and some delete a few or all files
on the hard disk drive. The term virus is a generic term and there
are various other forms including Trojan Horses and Worms. Viruses
usually attach themselves to system files and are run whenever the
system starts. They can them activate their payload whilst the computer
is running. Trojan Horses integrate with the system and consist of
small programs that allows someone else to access your computer when
you connect to the Internet. Worms infiltrate the system and then send
out e-mails, without user intervention or knowledge, to other computers
with a virus attached which can then infect other computers in the
same way. They send mails to people in your address book, and they
may use the addresses to make it look as though the mail came from
someone other than yourself.
It is normal on Windows for the display of known
file extensions to be turned off. This means that if an attachment
called 'mypicture.jpg.exe' arrives it is displayed as 'mypicture.jpg'.
This leads the user to think that it is an image file and is safe to
be opened. To display the full file name in Windows - open Windows
Explorer, select
View in the menu, then Folder Options. Click the View tab and deselect
the line 'Hide file extensions for known file types'. Click Apply and
remove all windows.
Never open attachments that you are not expecting
without checking them with anti virus software, even if they are from
a known source - they may have already been infected. There are many
anti virus programs available - one of which is AVG Anti virus at www.grisoft.com. |
