What do you call the tactic or behavior when someone makes a vague accusation along with a statement like "and yes, you do know what I'm talking about" when you have no clue what they're referring to, and they won't tell you?

A friend texted me before and wrote something like “you sure got off easy, didn’t you? And yes, you do know what I mean.”

I have no idea what she is talking about. I texted back what I think she might mean, but she has not yet responded. My relationships with people are generally drama-free, so this type of bullshit is confusing and unwelcomed.

Is there a name for this type of behavior? The tactic of a vague accusation and then not telling the person what they’re referring to?