What institution(s) has the power to impose non-criminal sanctions for campaign finance infractions?

ElectionOffences Act

http://www.agc.gov.my/Akta/Vol.%201/Act%205.pdf

Punishment and incapacitiesfor corrupt practice

11. (1) Every person who—

 [….]

(f) being a candidate or election agent knowinglymakes the declaration as to election expenses required by section 23 falsely, shallbe guilty of a corrupt practice, and shall, on conviction by a Sessions Court,be liable, in the case referred to in paragraphs (a) and (b), toimprisonment for a term not exceeding two years and to a fine of not less thanone thousand ringgit and not more than five thousand ringgit, and, in any othercase, to imprisonment for a term not exceeding one year and to a fine notexceeding two thousand ringgit. Offences under paragraphs (a) and (b)shall be seizable offences within the meaning of the Criminal Procedure Code.

(2) Every person who is convicted of a corruptpractice shall, subject to any specific provision to the contrary in anywritten law relating to any election, by conviction become incapable of being registeredor listed as an elector or of voting at any election or of being elected at anyelection, and if at that date he has been elected at any election, his seatshall be vacated from the date of such conviction: Provided that suchdisability shall cease on the expiry of five years from such conviction.

(3) A prosecution for a corrupt practice exceptany corrupt practice as defined in paragraphs (1)(d) and (e) shallnot be instituted without the sanction of the Public Prosecutor.