this has happend vt me , i would'nt say it is a virusor a torjan , you might have opened some porn sites and it must have some active x or java content which might have changed the home page of your browser.but not necessarly a spy ware , that's what i think , i don have much of info about spyware, just a min.....................
is that web site the one below

www.supersearch.com

is it, just checking@