Browser hijacking occurs when malware (malicious software) self-installs while cruising the Internet. Malware code changes the behavior of Internet Explorer™, typically adding several bookmarks to “Favorites” and changing the home page without the user’s permission. Browser hijacking often involves linking Explorer to adult websites and bombarding the user with adult pop-up advertisements.
Less often a browser hijacking might not involve adult content but will be repeated redirects to a site you did not click on and have no interest in. It might suddenly feel like your browser has a mind of its own. You intend to go to your home site, but your browser keeps popping over to another. Malware is redirecting your clicks to the destination site.
When struck by this behavior a user often attempts to change back the home page only to find the correction won’t stick. Malicious code can make changes to the system’s “hosts” file which maps domain addresses to corresponding Internet Protocol (IP) addresses. When you type “wisegeek.com” for example, the malware might have changed the corresponding IP from wisegeek’s address to some other IP.
Many malware programs take advantage of ActiveX scripts, which Explorer processes directly from Web pages. A popup might ask permission to install some piece of software with a message that is vague or misleading. The visitor might agree, believing the program is needed to view the site properly. Instead he or she has just given permission for a browser hijacking without realizing it.
Most spyware programs scan for malware and many programs will remove it. Modifications to Explorer can prevent browser hijacking, and can be done automatically by freeware programs like SpywareBlaster. Other popular freeware programs include Ad-AwareSE, Spyware Terminator, ThreatFire and Spyware Guard. You can also consider using a more secure browser such as Firefox®, which does not execute ActiveX.
To avoid browser hijacking and attacks by malware it is important to keep spyware current. Unlike typical software programs that only require occasional updates, effective spyware depends on constantly updated databases, same as anti-virus programs. Many popular firewalls incorporate spyware scanners. It is a good idea to use at least two spyware scanners regularly. One program can catch what the other might miss.