Haram is certainly a Norwegian surname. According to the Norwegian Bureau of Statistics there were 455 people surnamed Haram in Norway in 2004. You can check for yourself at
www.ssb.no, switch to English and go to the letter N for names.
As for the meaning, I'm sure you're right. There's a town called Haram on the island of Haramsoy ("Haram's island"?). The exact meaning of Haram? I'm stumped.