The Collaborative International Dictionary of English v.0.48:

evildoing \e"vil*do`ing\ n.
   evil behavior.

   Syn: transgression.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

evildoing
    n 1: the act of transgressing; the violation of a law or a duty
         or moral principle; "the boy was punished for the
         transgressions of his father" [syn: transgression,
         evildoing]

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "evildoing":
   crime, criminal, criminal tendency, criminality, criminosis,
   evil courses, felonious, feloniousness, iniquitous, lawbreaking,
   malefactory, malfeasance, malfeasant, malpractice, malversation,
   misconduct, misdemeanor, misdoing, misfeasance, misprision,
   misprision of treason, positive misprision, sin, sinful,
   thou scarlet sin, vice, viciousness, wicked, wrong, wrong conduct,
   wrongdoing