One viewpoint here:
http://www.christiananswers.net/bible/isa45.html
Not sure of the validity as I am not that well versed in Hebrew-English translations.
Isaiah 45:7 - What does it mean? The word translated "evil" here is the Hebrew word ra'. A better translation in modern English is "calamity" or "disaster" or "woe," as this word is translated in this verse in more recent translations. Dr. Henry Morris points out: "God did not create light, for He is light. It was the primeval darkness which He created in order to have a division between day and night. 'Evil,' as used here, refers to evil of a physical nature (storms), not moral evil." See other uses of the words "light" and "evil" in the Bible: Gen. 1:4; Exo. 10:22; 31:2; Lam. 3:38.
Neither am I versed in such translations, but the hypothesis Dr. Henry Morris puts forth here seems quite bogus. He says:
"God did not create light, for He is light. It was the primeval darkness which He created in order to have a division between day and night."
So could this mean that God did not create good, He IS good, and that He created evil to make a division between good and evil? He cannot have it both ways... He also says:
"'Evil,' as used here, refers to evil of a physical nature (storms), not moral evil."
Well the context certainly allows for this, because Isaiah 45 talks about the heavens, sun etc... Still, that does not change the fact that the concept of God has evolved since that time. elSatan at one point was merely an arm of YHWH, so it it quite possible that the "evil" here refers to moral evil and not physical evil.
Strong's entry under the word Ra' allows several translations including evil, distress, misery, injury, wickedness, calamity, wrong, adversity, unkindness, hurtfulness, unpleasentness, malignancy, pain... do these sound like the works of an "omnibenevolent" God?