[mal- bad + obsolete English feasance doing, execution, from Old French faisance, from fais-, stem of faire to make, do, from Latin facere]
The commission (as by a public official) of a wrongful or unlawful act involving or affecting the performance of one's duties.

Non·fea·sance (nŏn-fē'zəns)
n.

Failure to perform an act that is either an official duty or a legal requirement.