1. Virus-A program that makes copies of itself on the same computer without the user's knowledge. In addition to replication, some computer viruses share another commonality: a damage routine that delivers the virus payload. While payloads may only display messages or images, they can also destroy files, reformat your hard drive, or cause other damage.

2. Worm-A program that spreads or copies itself from one computer to another without user intervention. Compare this to a virus that only spreads between files on a single computer.

3. Trojan Horse (Trojan)-A computer program that appears to be something useful, but then does something malicious to your computer. This could range from destroying data to laying dormant and someday hijacking your computer to be used as part of a Denial of Service attack.

4. Malware-Malware is defined as a program that performs unexpected or unauthorized, but always malicious, actions. It is a general term used to refer to viruses, Trojans, and worms.

5. Adware-Adware is software that displays advertising banners on Web browsers such as Internet Explorer and Mozilla. While not categorized as malware, many users consider adware invasive. Adware programs often create unwanted effects on a system, such as annoying popup ads and, in some instances, the degradation in either network connection or system performance.

6. Spyware-A spyware is a program that monitors and gathers user information for different purposes. Spyware programs usually run in the background, with their activities transparent to most users.? Many users inadvertently agree to installing spyware by accepting the?End User License Agreement (EULA) on?certain free software.

7. Cookies-Cookies are text files that are created on computers when visiting Web sites. They contain information on user browsing habits. When a user returns to a Web site, a cookie provides information on the user's preferences and allows the site to display in customized formats and to show targeted content such as advertising. Cookies can collect user information that can then be obtained by another site or program.

8. Data Miners (tracking cookies)- Data Miners are applications that monitor, analyze, and collect specific information found in a database or volume of data from various sources. Data miners are not always used with malicious intent. Data mining programs allow companies to compile important client information, in order to enhance their services.

9. Phishing- Phishing is a form of identity theft in which a scammer uses an authentic-looking e-mail from a legitimate business to trick recipients into giving out sensitive personal information, such as a credit card, bank account, Social Security numbers or other sensitive personal information. The spoofed email message urges the recipient to click on a link to update their personal profile or carry out some transaction. The link then takes the victim to a fake Web site designed to look like the real thing. However, any personal or financial information entered is routed directly to the scammer.

10. Stealer- A stealer is a Trojan that gathers information from a system. The most common form of stealers are those that gather logon information, like usernames and passwords, and then send the information to another system either via email or over a network. Other stealers, called key loggers, log user keystrokes which may reveal sensitive information.

11. Keyloggers- Keyloggers are programs that log keyboard activity. Certain malware employ these programs to gather user information. There are also legitimate keylogging programs that are used by corporations to monitor employees and by parents to monitor their children. Keyloggers usually catch and store all keyboard activity - leaving a person or another application to sort through the keystroke logs for valuable information like logon credentials and credit card numbers.

12. Macro Viruses- During the late 1990s and early 2000, macro viruses were the most prevalent viruses. Unlike other virus types, macro viruses are not specific to an operating system and spread with ease via email attachments, floppy disks, Web downloads, file transfers, and cooperative applications.

13. Joke Programs- Joke programs are considered relatively harmless and are often designed to annoy or make fun of users. They do not infect files, cause damage, or spread to other systems. Many joke programs are designed to cause unnecessary panic - especially those that cause computers to behave as if something has been damaged. Abnormal system behaviors caused by joke programs include the closing and opening of the CD-ROM tray and the display of numerous message boxes.

14. Anti-virus program-A commercially available program that watches for viruses whenever your computer accesses a file, downloads a file, or downloads and reads e-mail. If a virus is detected, it will be either “cleaned” or moved to a separate location called “quarantine” where the operating system will not access it.

15. Firewall-This is a program that monitors data going in and out of your computer. It allows legitimate programs, such as Netscape, Internet Explorer, and the like to access the internet. It stops programs that might be some type of malware. You have control over what programs to allow or deny and what type of information to allow out of your computer.

16. Internet Security Program- Modern antivirus programs have been upgraded to a program that covers a multitude of possible threats to your computer. They contain features like anti-virus, anti-adware, anti-spyware, and a firewall. These not only catch and neutralize viruses, but also stop spyware and adware.

1. Install a good internet security program. It should be able to detect viruses, adware, spyware, and should include a firewall. In addition, it should update it's virus definitions (the list of viruses it can detect) once or more each day. (We recommend Trend Internet Security) Be wary of free security programs. They are probably worth every penny you paid for them.

2. Turn your Windows automatic update feature on. Microsoft makes security patches available to the public, but you must tell the computer to get them and install them. Failure to update the operating system (Windows) may result in the bad guys getting past your internet security program and doing damage.

3. Update your other programs, too. For instance, you have to visit Microsoft's site to update any Office components that you have.

4. The bad guys are always after your personal stuff like credit card numbers, SSN's, and passwords, but they are also after your computer. They want to use it to attack other computers and do illegal stuff so they can't be traced.