Sneakyware
Software that gets installed while installing another program, such as toolbars for your browser, or other software unrelated to the program you intended to install. Sometimes during the installation process of the intended software you are allowed to opt out of the sneakyware installation, sometimes you are not.
Joe: Man, why do you have so many toolbars on your browser.
Bill: They were sneakyware installations.
Bill: They were sneakyware installations.