New threats abound that require no action on the user to be installed if one uses IE or Outlook Express and has the preview pane enabled.

This is usually how a person learns about these new pests, parasites, spyware, web page or web search hijackers.

The 4 (free) tools I use to be sure the pests are found and removed are Adaware, Spybot, Cwshredder and Housecall.