Yes, it was due to malnutrition, the poor guy could hardly stand when they rescued him. That first picture is actually a couple weeks AFTER he was found in the attic, so he had already put on some weight
His coat was all dry and dead. He isn't quite as dark as that last picture though, just poor lighting.
I became a Foster parent through a group in San Fran called Bad Rap. I'm pretty much a miserable failure at fostering, since I'm now WAY too attached to him.