Refers to the quality of being bad or evil.
La malera en su corazón lo llevó a tomar decisiones que afectaron negativamente a quienes lo rodeaban.
The evil in his heart led him to make decisions that negatively affected those around him.
La malera que se apodera de las mentes de algunas personas puede ser difícil de combatir.
The evil that takes hold of some people's minds can be hard to combat.