Skillgate: Know What You're Installing

A skill tells an AI agent how to behave, what to access, and what to run. Hooks fire around its actions, and agent rules and MCP server configs set the edges of what it can reach. Those files come from public repositories, install in seconds, and most teams never review them.

One in the video is a skill called pdf-toolkit, advertised as "Extract, merge and split PDFs," which further down asks the agent to run a bundled installer, grant file and network access, and cache credentials. Two more like it follow. One tells the agent to ignore previous instructions and treat the file as system policy. Another ships ~/.aws/credentials to an outside host. An agent reads all of that as instructions and acts on it.

Skillgate is a free scanner from Mitiga Labs built for that surface: skills, hooks, agent rules, MCP server configs, and cross-platform instruction files such as CLAUDE.md, AGENTS.md, .cursorrules and .windsurfrules. Paste a GitHub, GitLab or Hugging Face URL, and it detects, flags, and scores the contents against more than a hundred rules across nine attack families, from prompt injection and credential exfiltration to hook RCE, tool poisoning and memory poisoning. Many of the rules cite a published CVE or the research behind them, and the whole rule set is readable on the site. What comes back is a verdict of Clean, Risky, Suspicious, or Dangerous, with a risk score from 0 to 100 behind it. Nothing is executed. Skillgate matches known techniques, so a Clean result means nothing in the file matched one.

Skillgate is community-powered. Every scan is public, including the ones you run, so each one adds to a shared map of what is out there. Tens of thousands of files have been through it already. Reading that map takes no account, and you need a free account only to run a scan yourself.

Try Skillgate for free.

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Related posts

Mitiga Minutes with Idan Cohen on Skillgate

The Mitiga Labs research that kicked it off, part 1 and part 2

Report: The Hidden Exfiltration Layer in AI Instruction Files

Breaking Skills: the long version of what Skillgate is and how it works