The root *lḥy ‘(to be) bad,’ of uncertain etymology, is still relatively well attested in Official Aramaic (DNWSI 571), but has been gradually replaced by *bˀš (HALOT 1830‒1831, DJPA 102, LSyr. 57, Jastrow 1988:183) and ceased to exist in later Aramaic dialects.
Proto-Aramaic *mlk ‘to advise’ is not attested in the Old Aramaic inscriptions, but common in later dialects. There is no other WS langugage which would display such a meaning: throughout WS, the root *mlk is associated with kingship (so in Aramaic as well) and/or possession. The meaning ‘to advise, to conseal’ is characteristic of Akk. malāku and milku. The possibility of an early Akkadism in Aramaic (perhaps beginning with the widespread noun *milk- ‘counsel, advice, plan’) lies at hand, but is not recognized (or even mentioned) either in the standard dictionaries or in Kaufman 1974 (Kogan 2015:419, with fn. 1202).
Related to *msk.
According to E. Lipiński (1970:84), probably an Indo-European borrowings (Latin misceo, Greeek μίσγω < PIE *meik’-, *meig’-, Buck 1949: 335)