Where a browser hijacker comes from
Many browser hijackings come from add-on software, also known as browser extensions, browser helper objects, or toolbars. Often, these items may improve your experience on a website by providing interactive content, such as animations. However, some add-on software can cause your computer to stop responding or display content that you don't want, such as pop-up ads.
How to recognize a browser hijacker
Your browser's home page is overriden, and when you try to open it, you're automatically redirected to the hijacker's website.