Doing everything to say fuck you to somebody without saying fuck you, or doing everything to indicate that somebody wants to pick a fight with somebody without actually starting one. Indirect agression isn't entirely passive, so it's not passive aggressive. The person is actively looking for trouble, they are just doing so in an indirect way.
He/she was a master of indirect aggression tactics.
What some people would call evil aggression.
He/she was a master of indirect aggression tactics.