Wikipedia
According to the Book of Mormon, Zenock was an old world prophet whose pre-Christian era writings were recorded upon the plates of brass. Zenock is quoted or paraphrased a number of times by writers in the Book of Mormon, including Nephi, Alma, son of Alma, Amulek, Nephi, son of Helaman, and Mormon.
Zenock is reported to have written and prophesied about the divinity, death, and atonement of the coming Messiah. In the Book of Alma (chapter 33 verse 17), Alma the Younger reports that Zenock was stoned to death for preaching that the Messiah would be the "Son of God."
Research on early manuscripts of the Book of Mormon suggests the name's intended spelling was "Zenoch" rather than "Zenock."
Outside of the Book of Mormon, there is no evidence that Zenock existed. However, there is evidence that writings of, and references to several ancient Israelite prophets were destroyed by the ruling class of the ancient Jews. There is a reference in the Dead Sea Scrolls to an ancient prophet known as the Teacher of Righteousness who was driven out of Jewish society because he preached of the coming of a Messiah. Outside of the Dead Sea Scrolls, there is no other reference to this person, and until 1950, there was absolutely no record of his existence. The scrolls state that the Teacher of Righteousness was descended from another mysterious prophet named Zadok, which might have been a transcribed or altered version of the Book of Mormon name Zenock. Indeed, non-LDS scholars identify this Zadok as the priest who anointed Solomon (1 Kings 1:39, 2:35) and whose dynasty officiated in the office of High Priest around 1,000-700 BC, some 100–400 years just prior to the timeline found in the Book of Mormon.