Browser hijackers change the default home and search pages in your internet browser without your permission.
You may find that you cannot change your browser’s homepage once it has been hijacked. Some hijackers edit the Windows registry so that the hijacked settings are restored every time you restart your computer. Others remove options from the browser’s tools menu, so that you can’t reset the start page.
Browser hijacking is used to boost advertising revenue and inflate a site’s page ranking in search results.
Browsers hijacked can be very tenacious. Some can be removed automatically by security software. Others may need to be removed manually. In some cases, it is easier to restore the computer to an earlier state or reinstall the operating system.