Might have some comments about this interesting lecture on demons and evil angels in early Judaism ... later.
Well, a thumbnail sketch can't hurt, most intriguing is that in Jewish literature diabology was not a high priority but in Mesoptamian philosophy and religion demons were a hot topic. Newsom covered a number of interesting non-Jewish theories about the nature and origin of demons. One theory was that demons were the offspring of gods who had moral birth defects, were cast out from the divine realm, and preyed upon humans. A second one, more associated with Lilith, an old Mesoptamian demon, is that demons were the souls of young women who died without having married or borne children and that they were motivated by malice and envy. Though Jewish speculative literature eventually came up with other stories and uses for Lilith in the earlier literature Lilith was apparently more a nasty and, unusually, named demon that seems to be alluded to by Isaiah that was referenced in non-Jewish literature.
We're tagging this in the "spiritual warfare" category because if you'd like to cross reference the lecture linked to above with some other ... uh ... discourses on spiritual warfare, you'll have that option.