These usually sneak in through a back door in Windows or one of your programs while on the internet. Sometimes come in with email or Plug-ins. When playing games someone turns off protection to speed up the game.

Sneaks in while you surf the internet. Ride in on information that you view or download. Associated with cookies that Internet Explorer uses. Also comes in some email.

Are allowed in by lack of protection or a cookie that came with Spyware or Plug in.

These are usually a product of enticement by Adware. Neat looking free stuff you're invited to download and use free. BEWARE of the "Smiley Faces" and screen savers.

At some time a Virus or Spyware has captured a site you visit. Later when you go to visit some other site, you get redirected to the "Look a Like" and are asked to Login. This is a trick.

Intentional maliciously done by the popup creator, it's a trick.

Emails are sent to you disguised as official messages from companies with which you do business with.