Hmmmm...that sure looks weird! This could be an Ellery Queen mystery on our hands--or maybe a Scooby Doo mystery! "Runky rensor reaks!" or funky sensor streaks!
Hmmmm...it looks like diffracted light. A few things come to mind. Is the rear element of the lens clean? Do you own or could you borrow another lens to cross-check the problem? Does the problem grow worse with higher and higher ISO settings--which might point us to conclude that it's electronic noise, for lack of a better word? Could there be something inside the mirror box, reflecting light that then hits the sensor?
I wonder if there is some type of foggy film on the sensor's anti-aliasing filter pack, which is a thin glass-like filter a couple of millimeters in front of the sensor....could you remove the lens, set the camera's shutter speed to B, or eight seconds or so, and then press the release, allow the mirror to swing up, and then "huff" a little breath onto the sensor, and angle it toward a reading light to see if there is some type of film on the AA filter?? icassell's idea of a cheap UV filter has some merit--but I have never seen straight, line-line ghosting or flaring from a filter--lots of crescents and round flares, but never linear defects. Still, if there is a filter on the lens, it's worth checking out. This is an odd one...