There is an user that continue to vandalize posts. He hasn't enough reputation to modify posts, but he's still trying to do it(I've reject at least 3 suggested edits for vandalism in the last few minutes).
He has never post an answer nor a question, so I can't flag none of it's post in order to signal his troll-like behavior to moderators.
It's not a big problem, but it's quite annoying.
How should we behave in this or similar cases? How can we notify moderators about that?