Yeah, it was deffo the blaster virus. In my first summer of working at my current job, there was a massive out break of this; ended up a gang of 20-30 techies walking over to the relevent buildings (8 in total), atleast 4 floors each, and 300 PC's per floor, (yeah, thats a lot). It looked like something outta a geeky movie.

It required the same patch, and also disabling the RPC service. Took all day too, in lovely weather, was gutted.