Viruses and other Malware
computer virus is code that can replicate. Viruses are usually designed
to damage or delete information on the target machine, but can be
little more than a piece of executable code that simply replicates
Other damage that
can result fom Malware are monitoring activity such as logging
keystrokes or viewing someone's desktop, extracting financial and
personal data, moving or destroying data including entire files.
days the threats include DOS or Denial of Service attacks; where large
numbers of controlled computer 'ping' or the target website or computer
Even more worrisome is examples Fifth Domain Warfare such as the
Stuxnet attack on the Iranian's Busheir nuclear reactor.
E-Mail Viruses -
to emails and
replicates by posting itself to names found in the
victim's e-mail address book.
A worm is any
self-replicating software that
inserts itself in a computer by exploiting vulnerabilities
in a system, invading the system one machine at a
A malicious or nuisance
masquerades as another type of programme, for example
a game or utility.
Once a Trojan is established there are numerous activities that can then be performed; spambotting, data theft, damage etc.
after the wooden horse given by the Athenians to the citizens of Troy
but hiding several men who emerged at nightfall to open the city gates
to allow the Greek army to enter.
Macro Virus -
This can only be
spread via applications
such as Word and Excel which have Macro capabilities.
Distribution can be via e-mail
attachments, from a
modified programme, a malicious cracker or social
engineer, as a macro.
Defences include firewalls, soft
and preferably hard
and anti virus software such as Kaspersky, Mcaffee and Norton.
virus can be tranferred via removable media and in the early days
almost all of the infections were carried about on floppy disks.
Nowadays, emails and downloading software, videos and music are the
and Adware programmes are not capable of reproduction and, strictly
speaking are not viruses - even though they may be equally difficult to
the ordinary internet browser having a good virus installed is the most
important protective measure, A hardware firewall is a feature of a
broadband router and is effective but you can also invest in software
firewall software for extra security. If you are a business with an
internal network then you can also invest in a range of measures
including boxes that check all devices on a network for