Is it possible for moth balls to absorb into food packages?

Yes! I stored several bags of Halloween candy in an old steamer trunk that had no mothballs, but still had a strong odor of mothballs years after I bought it at a yard sale. 6 months later I pulled the candy (still in its packaging) out of the trunk and tried some and found it tasted awful - the mothball chemical had gotten into the candy itself, despite being sealed in plastic and its individual wrapping.

Keep in mind that the chemicals in mothballs are highly toxic and carcinogenic - so do like I did and just throw it all out!