Funky toolbar/virus

my dad asked me to check up somewhere about this odd toolbar thing that's turned up on internet explorer on his computer. He doesn't know where it came from, or how... it just installed itself onto the computer, and sends up little pop-ups to 'tjar.com/passthrong'. in the list of toolbars in IE the toolbar is default (called 'RISMSHUGQUX'). also, it sends pop-ups to the usual casino and pay-for-crappy-porn sites. Also, any attempts to start up a search engine just resuts in it being rerouted to its own search engine, at tjar.com/passthrong. Seems really odd, since when he delete it it just comes back.
Ran virus scan - didn't help. Ran Adaware, and dad says that got rid of it, but it reinstalled itself on restart.
Any ideas? anyone know what its from, or what it does?