Sorry I do not know the exact answer, but it does sound like some sort of malware or at least unintentionally installed software. See for instance * this thread mentioning ''[/questions/816181 It is also linked to me being unable to change my homepage from searchqu.com]'' * [[is my firefox problem a result of malware]] * and a general answer by ''[/questions/873800#answer-244306 cor-el]'' <-- blue text clickable links You will need to look for any likely unrecognized extensions to firefox or other unknown programs and consider disabling them, otherwise it is likely to be out and out malware and it is a case of scanning with multiple tools to discover the problem.