In law, refers to a dated common law term now more frequently referred to as breach of trust or other dishonest, self-serving or criminal act by a public official during the course of his/her duties.
In The Common Law of England (Odgers, W. B., London: Sweet & Maxwell, 1911, at page 182), it was referred to as:
"... all misconducts in high places, all oppressive and overbearing acts on the part of those who are 'drest in a little brief authority'...."
Corruption, fraud or accepting bribes, extortion by a public or government officer, refusal to carry-out a lawful duty, scandalous conduct or electoral offences are samples of maladministration.
Some jurisdictions use the term in the context of judicial review (or in regards to the authority of an ombudsman) to include not just serious criminal offences by public officers, but even simple errors or omissions.