Ho fatto una ricerca in rete...
Dovrebbe essere un problema connesso ai Browser Helper Object (BHOs).


<<Browser Helper Object.

Sometimes a useful programming routine, a plugin for Internet Explorer, Mozilla, Netscape, to allow a little extra function, like the Adobe plugin that lets you see .pdf files in websites without d/l them. More often a nasty little routine that may redirect your input to the web pages of the developers choice, record everything you do, including your passwords and account details, divert your mail, record your bank account, and generally spy on you. There are many included in nastier forms of "free" programs most spyware repair/removers will kill off the bad.>>



Per la loro rimozione, vedi qui.
Inoltre, in questa pagina ne puoi leggere la lista.