Lilith is the tenth and lowest Qlipha, the shadow of Malkuth, the sphere of the Kingdom. It is the "night specter", the corrupted reflection of the material world, the outermost husk of the shadow tree, also given as Nehemoth.
In the scheme followed here it is ruled by Naamah, a name shared with two figures in the Hebrew Bible, a daughter of Lamech at Genesis 4:22 and a wife of Solomon at 1 Kings 14:21, neither demonic; the demonic Naamah is a later rabbinic and Kabbalistic development, named in the Zohar alongside Lilith and Agrat bat Machlat as one of a group of female demons associated with the night and with the seduction of men. That the lowest and outermost shell of the entire ten-fold list bears the same name, Lilith, as the ruler of the ninth shell above it is treated by commentators on the scheme as fitting its position: the material world is the point at which the Lilith figure's older Jewish literary identity, the demon of the outside and the night, is most fully at home. Spellings and rulers of the shells vary by source; the material is presented academically.
Malkuth carries no planet of its own in the classical sevenfold scheme, standing instead for the four elements and the manifest world entire; some Kabbalistic readings identify Malkuth with the Shekhinah, the divine presence dwelling in the world, which makes Lilith, its shadow, a particularly charged inversion of that indwelling presence rather than a simple absence of it.
Sources Encyclopaedia Judaica, 2nd editionMichael Berenbaum and Fred Skolnik (eds.) with The ZoharTraditionally attributed to Moses de Leon