Word for using something good for an evil/bad purpose? [closed]

The adjectives "treacherous" and "perfidious" can be used, since they imply that the persons so qualified are likely to do wrong to people because of their lies, that is, they cannot be trusted; however if lies such as the pretense to be good are covered by this characteristic, these words do not specifically mean "that cannot be trusted because they only pretend to be good while they are in fact evil-minded".

(OALD) treacherous adjective /ˈtretʃərəs/ ​that cannot be trusted; intending to harm you
SYNONYM deceitful
♦ He was weak, cowardly, and treacherous.
♦ lying, treacherous words

In order to get your point across precisely, you have to exert your command of the language and come up with telling phrases.

For instance

• He is treacherous in a peculiar sort of way; he insinuates himself into your affection through a display of caring that is nothing but fake.

This is nothing but an example, and all sorts of variants and alternative possibilities will do, each proper to a particular case; it is your responsibility as a writer or speaker to come up with that that will be exactly what you feel is true.

Exploitation, perversion, manipulation, desecration, defiling, corruption. Source: https://www.wordhippo.com/what-is/another-word-for/perversion.html#C0-3 (Third definition and fourth definitions)