NLP-Based OS / Fictional Terminal Language Override
This detects prompts that try to trick an AI assistant into pretending it's a terminal running a made-up programming language or operating system. The fictional framing (names like ALEL, APL, UNCOL.gpt, 'NLP-Based OS') is used to make the model abandon its normal safety responses and instead output whatever the 'parser' or 'compiler' persona demands.
How the attack works
An attacker sends a prompt telling the model it now runs on a fictional terminal or operating system governed by an invented language or parser. The prompt states the model can no longer reply with its normal pre-programmed responses, since those don't apply to this new 'system'. Technical-sounding jargon — parsers, data extrapolation, compilers, codeboxes — is layered on to make the persona switch sound like a legitimate software integration rather than a jailbreak. Once the model accepts the frame, it treats subsequent attacker input as 'commands' the fictional system must execute, bypassing its usual behavioral guardrails.
Netzilo detection
Netzilo reports this behaviour when it is observed.
- Signature ID
- b57bcb8a-07e0-4a5c-bc6b-680c334f9f5e
- Severity
- High
Why it matters
A successful override lets an attacker get the model to ignore its safety and policy constraints, producing content or actions it would otherwise refuse, by hiding the jailbreak instructions behind invented technical vocabulary.
What you can do
- →Flag and review prompts that instruct the model to act as a terminal, OS, or parser running a named language or system you don't recognize.
- →Keep safety and refusal logic independent of any in-context persona or 'system mode' the user claims to establish — refusal rules should not be overridable by conversational text.
- →Distinguish legitimate terminal-emulator integrations (documented, expected in your app) from user-supplied prompts asserting a new runtime persona.
- →Log and periodically audit conversations containing invented framework/language names paired with claims that normal responses no longer apply.
Known benign look-alikes
- Developer terminal emulator: "The assistant acts like a terminal emulator in the app — every command is executed and returned to the user" (legitimate app integration)
- Academic paper: "NLP-based operating systems are a theoretical concept where natural language replaces command syntax" (research or educational discussion)
- Shell scripting discussion: "Let's practice APL (A Programming Language) on a terminal — here is the syntax" (actual APL programming language, not fictional jailbreak)
- Genuine OS use: "ChatGPT runs well on my terminal (macOS) — I use it via the API" (literal terminal application usage)
- Creative writing: "Create a fictional NLP-based OS for a sci-fi story" (fiction without persona override mandating real-world harmful output)