A browser hijacker (sometimes called hijackware) is a type of malware program that alters your computer's browser settings so that you are redirected to Web sites that you had no intention of visiting. Most browser hijackers alter default home pages and search pages to those of their customers, who pay for that service because of the traffic it generates. More virulent versions often: add bookmarks for bad Web sites to the users' own bookmark collection; generate pop-up windows faster than the user can click them shut; and redirect users to bad sites when they inadvertently mistype a URL or enter a URL without the www. preface. Poorly coded browser hijackers -- which, unsurprisingly, are common -- may also slow your computer down and cause browser crashes.