A browser hijacker is defined as a “form of unwanted software that modifies a web browser’s settings without the user’s permission.” The result is the placement of unwanted advertising into the browser, and possibly the replacement of an existing home page or search page with the hijacker page.
How do you know if a browser is hijacked:
- Searches that are redirected to different websites.
- Multiple pop-up advertisement alerts.
- Slow-loading web pages.
- Multiple toolbars on a web browser not installed by the user.
Source : Norton