Viruses and malware

What are they, and how to stop them

“Mal-what??”  Or, What is malware?

The word malware is a contraction of MALicious softWARE. Things that do bad stuff to your computer, and/or the information on it. There are many types of malware, including:

  1. viruses and worms
  2. trojan horse programs (trojans)
  3. “drive-by” downloads (Active X components that get downloaded automatically when you visit a website, if you’re using Internet Explorer)
  4. spyware / adware

What are viruses and worms?

Computer viruses are so called because what they do is similar to biological viruses.  They invade a cell/computer, make copies of themselves, wreck the cell/computer and move on.  Worms are a special class of virus, which spread rapidly across the Internet by taking advantage of a security flaw - or people’s ignorance - to automatically invade a computer system and copy themselves to all other internet-connected systems. This creates havoc as it overloads the infected computers and networks. Meaning you can’t receive e-mail for a few days, or can’t access remotely-stored documents, or can’t use your PC at all because it takes half an hour for it to notice you clicked on something.

But that’s not the worst part of viruses and worms. Remember, they wreck the computer they infect.  Most malicious software, opens “backdoors” on your computer, that allow bad guys to get back in, and remote-control your computer over the Internet. Right now, hundreds of thousands of PCs are infected and are being use to send spam.

Are you safe from viruses and worms?

Most worms only affect Windows PCs, though there have been a few Unix-based worms, more so in the early days of the Internet.  So if you’re not using Windows, you’re automatically safe.  Likewise if you work for a large organisation, they’ll have an IT department whose job it is to sort out any damage when (and not if) it happens.  Of course, some departments are more competent than others.

The people who get hit the worst by viruses and malware are those without adequate support or protection  i.e. home users, small to medium-sized businesses, non-profit organisations and government departments.  If that’s you, here’s what you can do:

How to Avoid Viruses and Malware

  1. Use a Mac or Linux. They have virtually no viruses, are safe by design, and immune to PC (Windows) viruses.  If you have a Mac or use Linux, you can pretty much ignore the rest of this;  but still read the next point and use your common sense!
  2. Don’t infect yourself!  Don’t download dodgy software than contains viruses!
    1. Don’t install anything if you didn’t go looking for it yourself. Don’t download stuff just because a strange error message tells you to.  Would you let a stranger stay in your house if they knocked on the door saying “Hey, you need to let me in!  I’m not a psycho, honest”?
    2. Before installing anything, take a few minutes to research the program and its vendor.  Search for the program using a search engine, or look it up on ( and read the user reviews of it.
    3. Only download stuff from reputable sources (e.g. or the vendor’s website).
    4. Most of what you need is available free. Don’t pay for some strange application when you can search for a free alternative first.  Remember to take a few minutes to research the program, even if is free.
  3. Minimise your vulnerability - If you do use Windows;  turn on the Windows Firewall and Windows Auto-update, to patch any security holes as soon as Microsoft releases fixes.
  4. Protect yourself with anti-virus software, and anti-malware software (anti-adware, anti-spyware…)

Protecting yourself with anti-virus and anti-malware software

Of course, you don’t need to if you have a Mac or Linux!  Otherwise, use anti virus software as a last line of defence.  Now maybe you got some with your computer as a limited free trial (but watch out when it runs out - you’re no longer protected). If not, you don’t have to pay for decent protection.  Here’s how to get good anti-virus software, legally and for free:

  1. Go to IGNORE THE ADVERTS and look for the search box, at the top next to their logo. 
  2. Do a search for Avast. Again, ignore all the adverts and sponsored results.
  3. Download and install the home version. It’s free, easy to use and doesn’t suck up all your computer’s memory.  Set it to automatically run and auto-update itself.
  4. Other good free anti-virus programs include AVG Anti-Virus and Clam AV.

Viruses aren’t the only type of malware on the block. The other main types of malware are trojans, spyware and adware. And just like anti-virus software, there’s anti-spyware software [a good free one is SpyBot Search & Destroy] and anti-adware software [e.g. AdAware]. Again, search for those two on

As for trojans, most anti-virus software will deal with them too, or there’s Microsoft’s Malicious Software Removal Tool (MSRT) which is free and deals with over 1,000 common unwanted nasties.

Once again, be careful what you download. As I said, only download software from a reputable source.  Here’s how to be sure:

  1. Ask unbiased knowledgeable friends/colleagues - what do they use, what would they recommend?
  2. Don’t just search for something generic like “anti-virus software” on Google.  The most popular results might just have paid or tricked their way to the top.
  3. Instead, go to a reputable website with lists of good programs to download: for Windows PCs; or for Macs.
  4. If you’ve been recommended a specific program, so you know what you’re looking for, carefully search for it by name.  Remember there are probably many similar-sounding programs, some of them dodgy!
  5. Read the reviews/user comments on;  check the number of downloads and overall rating.  Only download well-known, popular software, not some obscure thing that only has a few thousand downloads, or that has loads of bad reviews.
  6. Virus-scan whatever you download before installing it (if you have a virus scanner).

The problem with anti-virus software…

Like your own immune system, a virus scanner can only stop viruses it already knows about.  When new malware appears, anti-virus software companies have to produce a new patch - like an antidote to that specific new virus. And it takes time to develop this antidote, then people to download it, so their chosen antivirus programs can recognize and stop the new virus.  This period of time - between a new threat and a fix being created - is the window of vulnerability.

If you catch the virus during its window of vulnerability, tough luck your anti-virus software WON’T stop it!  This is why Windows viruses continue to be such a problem.  See this comment from the Washington Post website: []

Why is it that antivirus/antimalware protected Windows machines are compromised daily while, after years with no protection, my Mac and Linux systems are trouble free? {…} It boils down to the “terrible three”.

  1. Gullible/uneducated/undisciplined users
  2. Poor site/network security practices
  3. Incredibly vulnerable operating system

What to do if you’re unlucky enough to get a virus

Unfortunately, once you do have viruses on your computer, it isn’t a simple thing to remove them. No matter how good your antivirus program may be. Sometimes a badly infected Windows PC simply isn’t salvageable, short of wiping it clean and re-installing Windows from scratch - or why not take the opportunity to try Linux!  Either way, I hope you made a backup of your important documents!  Why is all that necessary?  How come some people have to wipe and re-install Windows every six months or so?

The thing is, Viruses and malware - just like germs - don’t particularly want to be removed!  So they bury themselves deep into your PC.  It is not uncommon nowadays for malware to have self-protection measures built-in to prevent their removal. Such as blocking access to security websites - so you can’t find out about the virus;  killing beneficial security tool processes/services - so you can’t remove the virus;  and preventing Windows Updates from running - so you can’t get a fix to stop the reason you got the virus in the first place (unless you downloaded it on purpose - there’s no technological cure for carelessness!).

That’s when most people call in a computer expert, but in most cases you can fix it yourself.  You can get around these self-protection measures to remove viruses by restarting your Windows PC in “Safe Mode”.  Watch the screen while it’s starting up - they’ll be a message telling you to press F5 or F8 for more options - from there you can select Safe Mode.  Once you’re in Safe Mode, run your anti-virus and anti-malware software. Ideally you should keep a copy of your anti-malware software on a CD or USB memory stick, in case the virus has screwed up your anti-virus software.

To Summarise:

This excellent summary is from the above-mentioned Washington Post page:

Be extremely cautious about clicking on links in unsolicited messages, even if they appear to have been sent by a friend or acquaintance. Also, don’t install applications or programs if you didn’t go looking for them. Before you install anything, take a few minutes to research the program and its vendor first. If you decide to install the application, make sure to download it directly from the vendor’s Web site, if possible.

Or just DON’T RUN WINDOWS.  Get a Mac, or try Linux for free.  They are pretty much immune to all of this (but still don’t get complacent and don’t download weird stuff).  If my website can convince one person to use Linux or go try a Mac, I’ll be happy.  For more, see my page: What can you do?