List of computer threats and how to avoid them

Virus  

Is a program that infects executable files. When the infected file is executed, the virus replicates itself and spreads by infecting other executable files. Of course, the virus will try to infect your computer without your knowledge or permission. A virus generally has two phases; (1) an infection phase where the virus reproduces extensively, and (2) an attack phase where it does the damage it was programmed to do.

How to avoid:

• Install anti-virus software from a reputable company like Microsoft, Norton, or Trend Micro. Keep in mind that an anti-virus program will not keep you 100% safe from attacks. However, the chance of catching a virus is reduced.
• Update your anti-virus regularly. New viruses are created every day.
• Scan any new files for viruses that you download or receive before running them.
• Viruses and Trojan horses are spread by email. Just because the email is from someone you know doesn't mean it safe. Trojan horses can send themselves to people in the address book of the infected computer without the owner's knowledge. Always scan attachments before opening them.

Spyware

A category of computer programs that attach themselves to your operating system. They can suck the life out of your computer's processing power. They're designed to track your Internet habits, nag you with unwanted sales offers or generate traffic for their host Web site. Spyware usually ends up on your machine by clicking a button on a pop-up window, installing a software package or agreeing to add functionality to your Web browser. These applications often use trickery to get you to install them, from fake system alert messages to buttons that say "cancel" when they really install spyware.

How to Avoid:

• Be suspicious of installing new software, reject the installation of new components unless you have some specific reason to trust them.
• Get to know what your computer's system messages look like so that you can spot a fake. It's usually pretty easy to tell the difference once you get to know the standard look of your system alerts. Stay away from the "No thanks" buttons if you can help it, and instead close the window with the default "X" at the corner of the toolbar. For an even more reliable option, use the keystroke combination for "close window" built into your software. You can look in your browser's "File" menu to find it.

Malware

Along with viruses, one of the biggest threats to computer users on the Internet today is malware. It can hijack your browser, redirect your search attempts, serve up nasty pop-up ads, track what web sites you visit.  Malware programs can cause your computer to become unbearably slow and unstable.

Many of them will reinstall themselves even after you think you have removed them, or hide themselves deep within Windows, making them very difficult to clean. You can get infected by malware in several ways. Malware often comes bundled within  websites/free programs (social networking or file sharing programs seem to be the biggest culprits). These malware programs usually pop-up ads, sending revenue from the ads to the program's authors. Others are installed from websites, pretending to be software needed to view the website. some of them install themselves through holes in Internet Explorer like a virus would, requiring you to do nothing but visit the wrong web page to get infected.

How to Avoid:

• Always go to the source. If you see an offer that is too good to be true, than it probably is.
• A warning message that sets you on edge, go to a trusted source to confirm the information.
• If Paris Hilton tossed a midget in a bar or some guy in a third World country was offering millions to click on a link to provide details about yourself, your best move is to delete these messages and move on. 
• No links. Don’t click on any links sent to you in an email unless the person who sent it tells you directly. In addition, when you send a link, contact the person you sent it to and let them know that you sent it.
• If someone you don’t know is asking you for  personal information,  assume that they are up to no good. If you are worried that your bank really needs to confirm information, call them. If PayPal needs to communicate with you, email them directly.