prompt-injection

prompt-injection is a skill for Claude Code, Codex from MingyiSecLab/Mingyi-Atlas. It costs 55 tokens per session (1,344 once invoked), scanned A, a copy of prompt-injection, Apache-2.0.

A security-testing method for finding prompt injection in applications that use language models. Prompt injection is malicious text that tries to change an AI system's instructions or make it misuse its tools.

In plain words
What is it for?
Use it to test chatbots, document-search systems, coding assistants, browser agents, email tools, and other AI applications that read outside content or call tools.
Why use it?
It helps uncover attack paths where harmful instructions enter through documents, email, web pages, search data, or code changes and lead to data theft or unwanted actions.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to test chatbots, document-search systems, coding assistants, browser agents, email tools, and other AI applications that read outside content or call tools.

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Install with agentmods
npx agentmods add skills/mingyiseclab/mingyi-atlas/prompt-injection
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add MingyiSecLab/Mingyi-Atlas --skill prompt-injection
Clone the repo
git clone --depth 1 https://github.com/MingyiSecLab/Mingyi-Atlas

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for prompt-injection

README.md
[![agentmods](https://agentmods.dev/badge/skills/mingyiseclab/mingyi-atlas/prompt-injection/github.svg)](https://agentmods.dev/skills/mingyiseclab/mingyi-atlas/prompt-injection)
Your own site
<a href="https://agentmods.dev/skills/mingyiseclab/mingyi-atlas/prompt-injection"><img src="https://agentmods.dev/badge/skills/mingyiseclab/mingyi-atlas/prompt-injection/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for prompt-injection

Your own site · 80×15
<a href="https://agentmods.dev/skills/mingyiseclab/mingyi-atlas/prompt-injection"><img src="https://agentmods.dev/badge/skills/mingyiseclab/mingyi-atlas/prompt-injection.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,344 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. ✓ AI security review Sonnet 5 · 7 Sept 2026 📄 Read the review
Origin 98% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00055 $0.01344
Opus 5 $0.00028 $0.00672
Sonnet 5 $0.00011 $0.00269
Haiku 4.5 $0.00006 $0.00134

Measured 12d ago against content hash 19a387520867, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

prompt-injection scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

98% identical to prompt-injection — 3 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

src/skills/standard/analyst/prompt-injection/SKILL.md · 138 lines

How it starts

The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Prompt Injection Playbook

Every product shipping an LLM interface in 2026 has this surface. The bug bounty payouts are high because nobody has a clean defense, and the chain impact is unbounded (prompt injection → tool call → exfil → RCE in the agent's sandbox).

1. Target inventory — what counts as an LLM application

  • Chatbots with document upload / RAG
  • IDE copilots and code-review bots
  • Email assistants (classic indirect-injection vector)
  • Browser agents / AI-powered scraping tools
  • Customer support bots with CRM tool access
  • Agentic frameworks (LangChain, CrewAI, Semantic Kernel) running tools
  • CI/CD bots that read PR descriptions into a prompt
  • Internal "chat with your data" dashboards

2. Injection vectors

Direct

User-controlled chat input reaches the system prompt (or overrides it through role-play: "Ignore previous instructions and...").

Indirect (the real money)

Attacker-controlled content flows through a document the LLM later ingests:

  • PDF upload parsed by the LLM
  • Email body summarised by an assistant
  • Webpage scraped by a browser agent
  • Git diff read by a code-review bot
  • Slack message that a bot reads on trigger
  • RAG corpus poisoning (add a malicious document to the search index)

Tool-description injection

If tools are registered dynamically (plugin marketplace), a malicious plugin can supply a tool description that tricks the model into calling it.

3. Audit workflow

# Find LLM call sites
grep -rE 'openai|anthropic|bedrock|ollama|gemini|litellm' /workspace/src
grep -rE 'ChatOpenAI|ChatAnthropic|LLM\(|create_agent' /workspace/src

# Find prompt templates built from user input
grep -rE '(f"|f\x27|format\()[^"\x27]*\{(user|input|body|message|content|text)' /workspace/src

# Find tool definitions (LangChain @tool decorators, OpenAI tool_spec)
grep -rE '@tool|tools\s*=|function_calling|tool_choice' /workspace/src

For each tool definition, ask:

  1. Does the tool perform filesystem / network / shell / DB operations?
  2. What happens if the LLM calls it with attacker-chosen arguments?
  3. Is there a human-in-the-loop confirmation?

Read the full file on GitHub · 138 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 12d ago First seen · 138 lines · 55 tokens per session scan E 19a387520867

Subscribe to this mod's changes

prompt-injection is a skill published in the GitHub repository MingyiSecLab/Mingyi-Atlas (11 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 55 tokens to every session and 1,344 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 98% identical to prompt-injection, differing in 3 lines, and is treated as a copy.