Malware is short for "malicious software."   It is software that is intended to cause harm to the user's computer or compromise personal data.  Spyware is a specific type of malware that is installed on a computer without the user's consent.   These programs can wreak havoc in a number of ways, including monitor a user's behavior, stealing personal data, installing additional software, and redirecting browser activity.

To lower your risk of malware infections:

  • Download software only from sites you know and trust.
  • Set your browser security high enough to detect unauthorized downloads.
  • Check your operating system documentation to see if it may also have controls to prevent malicious software installations.
  • Use anti-virus and anti-spyware software, as well as a firewall, and set them to update automatically.
  • Don't click on links inside pop-up windows.
  • Don't click on links in spam that claim to offer anti-spyware software; you may unintentionally be installing spyware.

Clues that malware may be on your computer include:

  • A sudden increase in pop-up ads
  • Your Web browser takes you to sites other than those you type into the address box
  • A sudden or repeated change in your computer's Internet home page
  • New and unexpected toolbars
  • New and unexpected icons on the system tray at the bottom of your computer screen
  • Keys that don't work (for example, the "Tab" key that might not work when you try to move to the next field in a Web form)
  • Random error messages
  • Slowed computer performance

If you suspect you have malware, use the latest version of anti-virus and anti-spyware to clean your computer.  Here is a list of a few reputable security software vendors and their Web sites: