What Everybody Ought To Know About Detecting The 5 Different Types Of Computer Virus

Hopefully you have been paying attention and have secured your network and run through the basic security tips that I’ve written about.

You haven’t?

Ok, in that case, I guess it is fortunate that there are ways to tell that your system has become infected with a virus.

If your pc is playing up and you are unsure whether it is due to a virus infection then read on…



The following signs may indicate that you haven’t been paying enough attention to me and that your computer may be infected –

  • You have to kick your computer to get it to keep up with you
  • Your computer goes on strike, especially when you are trying to do something important
  • Your computer reboots itself just as you start to watch your favourite por
  • The unknown error messages you receive look weirder than normal
  • Strangely, buggy software works properly for the first time ever
  • Those pictures of naked women you try to print get stuck in the ether. Again.


If any of those symptoms sound familiar then there is  good chance that you have downloaded or installed something you now wish you hadn’t.

There are, quite literally, millions of different types of gremlin that can affect your computer, be they viruses, trojans, worms or spyware, etc.

Here are 5 of the more common types of virus that are just itching to get acquainted with your system –


A boot sector virus affects a computer’s hard drive.

Historically, they also targeted floppy disks too, though hardly anyone uses them nowadays.

A hard drive is made up of platters which are further divided into sectors.

The first sector on a platter is known as the boot sector and contains the Master Boot Record (MBR).

The MBR is kind of like the brains of the hard drive, telling it how to load the operating system when the computer is switched on.

Therefore, if the Master Boot Record of a drive becomes infected with a virus, your whole system will become compromised and there is the chance that any writable media inserted into your system could also become infected too.

Boot sector viruses can be spread between computers by sharing disks, though this is less common now that floppy disks have been superseded.

Boot sector viruses can usually be cured or fixed with a good anti-virus program.


A program virus is, perhaps, the most likely variant you will come across.

Typically, these will arrive either as email attachments, or as part of larger files downloaded from peer-to-peer networks.

More often than not, the virus will appear to be a genuine program with a file extension such as .bin, .com, .exe or .txt, though there are many other possibilities too.

Once the file has been opened the virus will become active and will typically replicate itself into other programs on your computer.

Once again, a good anti-virus program should protect you from such viruses.


Chameleon viruses, also known as polymorphic viruses, get their name because they are able to camouflage themselves by changing the way they appear.

What this means is that they change their virus signature every time they infect a new file.

This makes them harder to detect as anti-virus programs typically identify viruses by their unique signature.


As you may gather from the name, a macro virus is programmed as a macro that is embedded into a document.

There are many applications that support macro languages and two of the more popular ones are Microsoft Word and Excel.

If your system becomes infected by a macro virus then it will find it’s way into every document you subsequently produce.

Macro viruses have been around for a while now but if your anti-virus package is more than a few years old then it may have trouble detecting them.


Somewhat like a chameleon virus, a stealth virus can disguise itself in order to try to avoid detection.

Such disguises include altering its file size and concealing itself in memory.

Stealth viruses are certainly not a new type of threat – the first instance of one was Pervade which was created in 1975.

A good anti-virus program should be more than capable of scanning both your hard drive and memory in order to root out stealth viruses.

About Lee Munson

Lee's non-technical background allows him to write about internet security in a clear way that is understandable to both IT professionals and people just like you who need simple answers to your security questions.


  1. i hate virus of any kind

  2. My favorite virus to get infected with is a polymorphic virus. They are really nasty and most antivirus programs don’t remove them correctly. To be virus free, I recommend to not use microsoft products :mrgreen:

    • Your favourite?


      I believe I read on one of your profiles somewhere that you either are, or were, a hacker at some time?

      If that’s correct, have you ever created a virus Bobby?

  3. Stuart Reynolds says:

    “Your computer reboots itself just as you start to watch your favourite por”

    I wonder how that sentence ends? lol


  1. […] do not know what a virus consists of so they put bad thoughts into their mind about how it is some kind of weird […]

  2. […] Antivirus software is designed to protect your system from scripts and programs that can damage the operation of your computer or steal your personal data. […]

  3. […] some respects computer viruses are like biological viruses, such that they can range from the mildly annoying to the downright […]

Speak Your Mind