My sense as a non-native is that either of these might be better, to emphasize the existence of злоба in the here-and-now:

"Откуда берётся злоба?" (present tense: "Where does malice come from?")
"Откуда взялась злоба?" (past perfect: "Where did/has malice come from?")

The form you used suggests to me "Where might it come from in the future?"

P.S. And note that злоба is closer to "spitefulness" or "malice directed against another person"; if you mean "Evil" in a more general sense, like "the Dark Side of the Force," зло might be better.