Computer Viruses and Malware What are they-

							?Computer Viruses and Malware What are they?

I often get asked what is a computer virus, how does it differ from a worm or Trojan
and how do they get into my computer? Please find below my article, giving you a
brief explanation of these terms and how easily they can infect your system.

What is a Computer Virus?

Computer viruses are annoying at best and can be extremely destructive at worst. A
computer virus is a piece of code which can attach itself to one of your files or
programs, enabling it to spread to other computers infecting as it goes. This causes
damage to files, software and hardware.

Computer viruses can range in severity in the same way as an organic virus. With an
organic virus, unless kept in complete isolation, it usually spreads through human
interaction. The difference is, (other than the obvious) a computer virus needs human
interaction to enable it to spread, such as sending an email or sharing a file.

What is a Worm?

Similar to a virus, a worm is designed to copy itself across computers, but the horror
is that it does this automatically.

It does this by taking control of features on a computer that transport files and
information. Once on your system they have the ability to replicate in great numbers,
very quickly. One of the things that they are famous for, is sending out copies to
everyone in your address book and if the recipient is unaware, it will do the same to
theirs.

They have the potential to cause heavy traffic, clogging networks and in extreme
cases slowing down the entire internet.
So if you are waiting twice as long for pages to load, this could well be a possible
cause.

What is a Trojan?

As in the Trojan horse of Greek mythology, which appeared to be a gift, but actually
contained soldiers, Trojans appear to be useful software. Unfortunately, they often
arrive as an email attachment, usually appearing to be from a legitimate source, but
when opened lead to a trail of destruction. They can also be present in free software
that you may download, so beware!

What is Malware?
Malware is a term that is used to describe malicious software
programs. The things that are included in this are spyware, adware, and cookies.

What is Spyware and Adware?

It has been estimated that 90% of all computers on the internet are infected with some
type of spyware.

Spyware refers to programs that can use your internet connection to send information,
normally without your permission or knowledge, to another computer. The
information that it then gathers could be a record of your browsing habits. This can
include things that you have downloaded and even personal information such as your
name and address.

There are different types of spyware which perform different functions. Some may
change your home page, producing pop up personal ads, even if you are not online,
and may even highjack your browser, taking you to an unexpected site. Spyware that
serves you personalized ads is also known as adware.

Some free software or programs have spyware included. Some of the more legitimate
programs mention in their terms and conditions, that they may gather information,
although most people do not tend to read this. However, spyware does not have to
come bundled in a program. It is most commonly installed surreptitiously, often in the
form of a pop up, or asking you to install a plug in, to enable you to display the site
correctly. Spyware can use the local resources of your computer, such as processor
and memory power, as well as some of your internet bandwidth.

So if your computer:
    slows to a crawl
    if you click on a link to a site and you end up at another site, due to your browser
having been hijacked,
    you enter a search and received an unexpected result
    you get pop up ads that address you by name from a site that you havent visited
    you click on your home page and it takes you to a new site and when you try and
switch back the same site appears again,

Then you probably have been infected with some form of Malware.

I hope you found this useful. For software to protect against and help remove
unwanted malware, please visit the resources page on