The Collaborative International Dictionary of English v.0.48:

Malum \Ma"lum\, n.; pl. Mala. [L.]
   An evil. See Mala.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Mala \Ma"la\, n. pl.; pl. of Malum. [L.]
   Evils; wrongs; offenses against right and law.
   [1913 Webster]

   Mala in se [L.] (Law), offenses which are such from their
      own nature, at common law, irrespective of statute.

   Mala prohibita [L.] (Law), offenses prohibited by statute,
      as distinguished from mala in se, which are offenses at
      common law.
      [1913 Webster]