SON SON
Lesson 1: Viruses, worms, and Trojan horses
in this lesson, you’ll learn what viruses and worms are, how they can enter your PC, and how you can remove them quickly and easily.
Viruses and worms are computer programs deliberately designed and written to alter the way your computer works, without your permission or knowledge.
A virus has two properties:
Some viruses are designed to cause damage to the PC they are on by destroying programs, deleting user files, or reformatting the hard drive, but other viruses are merely prankster programs that spread and present a message in one form or another. But even these joke viruses must be removed because they can consume valuable system resources or cause the computer to crash.
A worm is different than a virus; it is a program that can spread from system to system within another document, such as an e-mail message or a Microsoft Word document.
A Trojan horse is a file that claims to be innocent but harbors malicious code that might do one of a number of different things, such as delete files or steal your data. The main difference between a Trojan horse and a worm or a virus is that a Trojan horse does not replicate itself.
It is quite easy to protect yourself from viruses, worms, and Trojan horses: install a good antivirus program (for example, Norton AntiVirus 2007, McAfee or ZoneAlarm) and keep it up-to-date. A good antivirus scanner will not only be able to detect and block any viruses, worms, or Trojan horses that try to enter you system, it will also be able to remove any malware already installed on your PC.
It is important to keep the antivirus application updated (it’s recommended that you upgrade the main software package yearly) and that you download and install the latest antivirus detection databases regularly, because hundreds of new viruses and worms are released weekly. If you don’t keep the detection databases in the program up-to-date, the app won’t be able to detect and repair anything new that finds its way onto your PC. Consult the help file or manual for your antivirus program to find out how to do this (most are able to update themselves automatically).
Scanning a file using Norton AntiVirus software
Here are a few other precautions you can take to keep yourself safe:
Visit Download.com for a selection of popular anti-virus software downloads that you can try on your PC.
Lesson 2: Spyware and adware
In this lesson, you’ll learn what adware and spyware is and how to protect yourself from it and remove it from your system.
In Lesson 1, you learned that viruses, worms, and Trojan horses are programs designed to carry out malicious activity on your PC. You also learned that viruses and worms are capable of replicating automatically and spreading from system to system. In this lesson, you will learn about adware and spyware.
Adware is an application installed onto a PC without the user’s knowledge. These apps have a single purpose: to deliver ads to the user. This is a deliberate business model because the people behind the adware are paid to pipe ads to users who unwittingly host adware on their PCs. Technically, adware is more of a nuisance than malicious, but it can cause system crashes because it makes PCs unstable.
Spyware is a different matter. This type of application is designed to spy on you. It might spy on your Internet surfing habits or collect information from your computer about your identity, your credit card numbers, or your passwords. Spyware is particularly bad because it can capture all sorts of data and send this back to criminals who can use it to steal your money or identity.
As a rule, the most common sources of adware and spyware are low-quality, dubious Web sites (for example, sites that deal in pirated software or music). Most adware and spyware is installed by either tricking the user to click something and install an application or by exploiting a flaw in the browser or operating system.
If you want to get the best from your PC, you don’t want to have adware or spyware running on it. Many antivirus packages (for example, Norton AntiVirus 2007, McAfee or ZoneAlarm) can detect and remove certain adware and spyware, but it’s best to have a separate program to look for and remove these unwanted PC pests.
Microsoft Windows Defender scanning a PC for spyware and adware.
A number of free applications are available for you to choose from. One is called Windows Defender and is available from Microsoft. Another good program to install and scan with on a regular basis is called Ad-Aware by Lavasoft. You can install both of these on your system, having Windows Defender running all the time and using the latest Ad-Aware to scan your system daily (if you are security conscious) or weekly to check for and remove anything that might have managed to sneak by Windows Defender.
Ad-Aware from Lavasoft, a good spyware and adware scanner.
Another thing you should do if you are running Windows XP is to make sure that you have installed Service Pack 2 (also known as SP2). Many of the exploits that adware and spyware use to install themselves on PCs without the user’s knowledge have been patched in SP2. Visit Microsoft’s site and install all the patches your operating system needs.