Symptoms

• Several signs indicate that a Web browser has been hijacked, according to Microsoft's Safety and Security Center. The browser's homepage or other settings are often changed, and links are added pointing the user to Web pages he usually avoids. Often, the browser can no longer navigate to certain types of Web pages, such as anti-spyware or other security software websites. In addition, the user's screen is often barraged with pop-up advertisement, and new toolbars or "favorites" have been installed to the browser that the user doesn't want. The computer also seems to be running "sluggishly," according to Microsoft.
  
  

Background

• Some websites pay for browser hijacking services because of the forced Web traffic they generate. Browser hijackers can be installed in multiple ways. In some cases, when the user is installing free software, the browser hijacker is mentioned in the fine print of a user agreement, which many people either agree to without reading at all or by giving it a superficial reading. In addition, browser hijackers can be installed without the user's permission if the user downloads an infected email attachment through a file-sharing program or by simply visiting a website that automatically loads a malicious program onto the computer, according to SearchSecurity.com.
  
  

Fixes

• According to Microsoft, users can take several steps to either avoid or rid themselves of browser hijackers. Users should avoid websites that have been identified as potentially dangerous by their search engine. To stop the barrage of pop-up ads, Windows users can open Task Manager, click on the Processes tab and end the process controlling their Web browser (such as Iexplore.exe for Internet Explorer). If the homepage has been changed, the user can manually reset her browser settings. She can also disable add-ons, such as ActiveX controls, browser extensions, toolbars or browser helper objects, which is where many browser hijackers originate. In addition, users should install a trusted anti-spyware or anti-virus program that can scan for and remove hijackers and other malware.
  
  

URL Hijacking

• Another form of browser hijacking is known as URL hijacking, according to PCMag.com. In this case, websites take advantage of common mistakes computer users make when typing a Web address into their browser, registering a domain name that is a commonly misspelled version of a popular website. This results in users being sent to a website that may offer competitive products, generate a barrage of pop-up ads or give information about an entirely unrelated cause.