Subdomain Enumerator

Discover subdomains for any domain using two complementary techniques: DNS brute-force resolution and certificate transparency log mining via crt.sh.

Quick Start

python3 scripts/subenum.py example.com

Commands

# Basic enumeration (built-in wordlist + crt.sh)
python3 scripts/subenum.py example.com

# Custom wordlist
python3 scripts/subenum.py example.com --wordlist /path/to/wordlist.txt

# Faster with more threads
python3 scripts/subenum.py example.com --threads 20

# DNS only (skip crt.sh)
python3 scripts/subenum.py example.com --no-crtsh

# JSON output
python3 scripts/subenum.py example.com --json

# Save results to file
python3 scripts/subenum.py example.com --output subdomains.txt

# Verbose progress
python3 scripts/subenum.py example.com -v

Options

Techniques

1. DNS Brute-force — Resolves {word}.{domain} against DNS for each word in the wordlist. Returns IP addresses for live subdomains.
2. Certificate Transparency (crt.sh) — Queries public CT logs for certificates issued to *.domain, revealing subdomains that may not respond to DNS but have had TLS certificates.

Dependencies

pip install requests

Notes

• Built-in wordlist covers common subdomains (www, api, mail, staging, etc.)
• For comprehensive scans, use a larger wordlist (e.g., SecLists DNS wordlists)
• Results are deduplicated across sources
• Use responsibly — only scan domains you own or have authorization to test