A
virus is a program that can make copies of itself and spread itself from one machine
to another without the help of the user. Viruses carry out other actions.varying
from the annoying (altering a computer's homepage) to the damaging (deleting files).
Viruses are computer programs and therefore can delete files, format hard drives,
and overwrite the BIOS. However, some viruses do nothing at all.
How
do viruses spread?
Email-borne
virus: An executable file is attached to an email, which usually has a tempting
or intriguing subject line to encourage the receiver to open the email. When the
attachment is opened, the virus is activated, and the user's computer becomes
infected. Just like a human virus it will then usually infect others (in this
case, by attaching itself to new email messages that it sends to your contacts)
while going about it's other task of attacking the carrier. So once your computer
is infected, all your friends and contacts are at risk as well.
Email
virus: Unlike an attached file that the user must execute, email viruses are
embedded within the email.. Attachments may be involved and will automically execute
when the user reads the email. Thus, email viruses differ from email-borne viruses,
the latter which require users actually open the attachment in order to become
infected. Historically, email viruses have targeted Microsoft Outlook and Outlook
Express users, though theoretically other mail clients could pose a risk. In any
event, if an attachment is involved the user can still choose to open it and become
infected, as was the case with the BadTrans.B worm. For this reason, it is equally
important to understand both how to prevent attachments from being automatically
executed by the mail client and how to recognize potentially harmful attachment
types. Any executable type attachment has the potential to be infected.
Infected
files: Be careful when downloading files from the internet. If a file that
you download is infected and your computer is not protected then it is infected
immediately. The same applies to software distributed on disks, check them before
installing anything - whatever the source.
Stealth
download: A misleading dialogue box can often cause the user to unwittingly
accept a download/installation without realising it.
Symptoms
A
virus can basically cause practically every kind of computer problem possible,
including slower operation, decreased memory, erratic disk drive activity, loss
of functionality, crashes and lock-ups, sometimes displaying messages, or even
playing musical tunes, however many give no initial sign of their presence. So
don't assume that your not infected if nothing seems to be wrong, likewise don't
instantly assume that you have a virus when your computer misbehaves.
Options
If
you do not need or recognise a file or attachment, don't open it. It's
really vital to have anti-virus software on your computer with email use and abuse
increasing everyday. Many people have alarms fitted to their cars and property
these days. Fit one to your email - it's just as important. Your computer contains
your personal property just as your home does. [Click
here]
