Sububy is an all-in-one subdomain enumeration tool written in Ruby by A3h1nt. It focuses on modularity and accurate discovery, making it useful for red team reconnaissance, OSINT workflows, and bug bounty triage.

What It Does

Sububy includes ten core modules:

• Cert – uses Certificate Transparency logs
• Brute – performs wordlist-based brute force
• Dnsd – queries DnsDumpster (API key required)
• Vtotal – retrieves data from VirusTotal (API key required)
• WebArch – extracts historical domains from the Wayback Machine
• Csp – scrapes subdomains from Content Security Policy headers
• Sort – removes duplicates from output
• Live – checks for live web services
• Sshot – captures screenshots of live targets
• Info – collects HTTP response codes and headers

Modules can be run individually or chained together via CLI or from within Ruby itself.

Installation and Usage

Run a full scan:

Strengths

• Modular and scriptable
• Useful API integrations
• Screenshot and HTTP response data for post-enum triage
• Suitable for headless workflows via IRB or CLI
• Lightweight dependency set (Ruby + gems)

Limitations

• Ruby is required, which may not be preinstalled in many environments
• API limits apply for Dnsd and Vtotal modules
• Focuses more on precision than volume (not a replacement for massdns)
• No built-in JSON output or API for direct integration

When to Use It

Sububy is ideal for:

• Reconnaissance in stealth-focused environments
• Bug bounty triage for live hosts and headers
• Adding contextual intelligence (e.g. screenshots, CSP leaks)
• Workflow integration with other Ruby-based tools

Use Sububy when you want more than just domain names—particularly when you need to verify what’s alive, what’s misconfigured, or what headers are exposed.

Recommendations

• Integrate Sububy into a larger recon pipeline by chaining outputs to Nmap or HTTP probing tools
• Use the Sort and Live modules after any brute force or CT scan to reduce noise
• Consider saving screenshots and headers for post-assessment analysis or reporting
• Pair with assetfinder or amass to compare coverage across passive sources

You can read more or download Sububy here: https://github.com/A3h1nt/Sububy