Well, First let me explain the terms. Malware is a general all encompassing term that includes both spyware and viruses. Malware is defined to be any software code that is written for malicious purposes. Trojans, worms, and adware are also all types of malware.

As I said, Spyware is a type of malware. It generally gets installed, runs, and collects information about the user without their knowledge. The presence of spyware can be hidden from the user and can be difficult to detect. On the other hand some spyware will take the “Hide in plain site” approach. It will pose as an anti-virus or anti-malware program. Most of the time it will pop up messages informing you that you are infected with viruses/malware and it wants to you click on a link to clean your system. In reality it is not going to do anything beneficial for you. What it will most likely do is ask you to enter your credit card information or other personal info of some kind.

The term “virus” is commonly but erroneously used to refer to other types of malware. A virus is defined as a computer program that can copy itself and infect other computers. There are many methods for a virus to replicate itself in order to spread. Years ago it would imbed itself onto a floppy disk and would then infect another computer when that disk was moved from one system to another. In more recent years a lot of viruses would send itself as an attachment in an email to the people on your contact list. This has a pretty high infection rate because people will see that the email is from someone that they know and won’t hesitate to open it. (I have written a separate blog post about email based threats. You can read it HERE.) This is by no means the only way viruses can spread however. Floppy disks have gone by the way side but USB flash drives are now very commonly used. The viruses can take advantage of these devices the same way as the floppy disks. A virus can also spread without any human interaction at all through vulnerabilities in almost any computer software. This is why any software vendor is generally constantly updating and patching their software.

While spyware and viruses are the two main types of malware circulating today I still feel that it is pertinent to mention a few others. Adware is software specifically written to display advertisements. This is most often in the form of “pop-ups”.

A trojan horse is a malicious program that masquerades as a valid application. So while you think you are downloading and running a harmless game, for example, you can running a program written to delete all of your documents.

Rootkits are lesser known and less common than other forms of malware. They are difficult to detect and even more difficult to remove. Generally speaking they are used to obtain continual privileged access to a computer. Once this is done, the writer of the rootkit can basically do anything he wants with the compromised system.

There are numerous other, more specific, types of malware. I have only covered the most common in this article. I only intend this to be a general overview to give people some quick information. Now that I have described some of the main types of malware, let me write a little about protecting yourself from it and how to remove it once your computer is compromised.

First things first, you absolutely must have anti-virus software on your computer. If you do not you are asking for trouble. Most anti-virus packages out there now days are sold as “internet security” suites. They will include anti-virus, anti-spyware, anti-spam, and a software firewall. All of the above are good to have (Although the firewall can cause a lot of headaches in other areas, but more on that in a future post.), but what you have to remember is that nothing is 100% secure. It is an ongoing battle between the anti-virus companies and the virus writers, and you are stuck right in the middle. As soon as the anti-virus companies find and block a certain virus/spyware the creator will modify it or create a new one to get around the protection on your computer.

The two big names in the anti-virus market are McAfee and Norton. Both are good products, but both offer pros and cons just as anything else. These are both paid services and I believe both use subscription based licensing. There are also a handful of free anti-virus applications out there. AVG and Avast are two examples of free anti-virus software that are available. These free services generally offer a free package that is just basic protection and will offer other paid versions that are a more complete suite of tools. I would only recommend these free options to people who are a little more computer savvy and are much more cautious and knowledgeable about what not to download or click on.

Now as I said before no anti-virus/anti-spyware program will catch 100% of everything out there. This is why there is a long list of utilities that I use to remove malware once it has already made it onto your system. I will cover a couple of the safer, more user friendly ones.

Spysweeper by Webroot is a quality non-free application. It not only does a descent job of removing spyware from a PC, but it will also constantly run and try to protect you from getting it installed on the system to begin with.

Another great tool that I use all of the time is MalwareBytes Anti-Malware. It is free and does a fantastic job of, in my opinion, cleaning up about 95% of the malware out there. Spybot Search and Destroy is yet another tool that I would recommend to others. It is another free tool and also does a good job of cleaning up most spyware. It also has an immunization option which attempts to stop you from going to known spyware infected/infecting websites. There are many other tools I use to remove malware from systems I work on, but most of them are more advanced and also dangerous to use if you tell it to remove the wrong thing. For most average malware infections the tools I have listed here should be sufficient to clear up the majority of them.