What seem to be the earliest (it is difficult to assign a date to the various documents that have been preserved as part of the OT) documents that form the OT, do not seem to provide much information about 'Satan.' And, for example. was the 'serpent' story of Genesis 3 really a later interpolation added between chapter two and four? If so, there does not seem to be much knowledge of this character in early judaism.
Perhaps the document known as Job, marks the first real introduction of Satan to Jewish thought. Out former brothers, claiming guidance by holy spirit (though they still seem prone to error) claim that it was written by Moses, though they offer no evidence for that in the Aid book. But what if it was really written during the Babylonish captivity? The Wikipedia entry suggests that time period.
Quote: "Rabbinic tradition ascribes the authorship of Job to Moses, but scholars generally agree that it was written between the 7th and 4th centuries BCE, with the 6th century BCE as the most likely period for various reasons."
Such a date makes it possible that the writer may have been a Jewish scribe exposed to Zoroastrian thought , particularly if it was later in that time during the the initial Persian period. In Zorastrian thought we find a much greater detail about the opposing forces of darkness and light.
By the time we get closer to the Jesus time, we may observe in the writings of the Qumran community (The Dead Sea Scrolls) even more detail about the opposition of light and darkness. Satan now is a much more developed personality.