Subfinder Fast Passive Subdomain Enumeration Tool
Subfinder is a passive subdomain discovery tool by ProjectDiscovery that finds valid subdomains for websites using curated online sources. Optimized for speed and stealth, it integrates cleanly into security reconnaissance pipelines via stdin/stdout support.
Prerequisites
Go 1.21+
Installation
Choose whichever fits your setup:
- Copy this skill folder into your local skills directory.
- Clone the repo and symlink or copy the skill into your agent workspace.
- Add the repo as a git submodule if you manage shared skills centrally.
- Install it through your internal provisioning or packaging workflow.
- Download the folder directly from GitHub and place it in your skills collection.
Install command or upstream instructions:
go install github.com/projectdiscovery/subfinder/v2/cmd/subfinder@latest