Sometimes called Home Page Hijackers, browser hijackers have the ability to change your default home page as well as other Web browser settings. Common behavior also includes adding advertising, pornographic, or other unwanted bookmarks, creating pop-up advertisements, and redirecting mistyped or incomplete URLs. Additionally, browser hijackers may redirect your searches to "pay-per-search" Web sites.
Browser hijackers are programs that replace the browser home page, search page, search results, error message pages, or other browser content with unexpected or unwanted content.