Classifier? Prompts?

This is commands blocked in settings.json

I block destructive filesystem operations and destructive git usage via “deny” directives.

I also have instructions injected in CLAUDE.md and re-injected on every single prompt.

Claude just tried to use command concatenation to break those rules. I have also seen it writing a script with rm inside and running it.

The commenter you replied to mentioned that you can customize the auto mode classifier by providing a prompt, implying that this would be a more robust way of constraining Claude's behavior. It wasn't clear from your response whether you were using this functionality. You might try it out as a way to more reliably prevent these kinds of workarounds.