exploiting-broken-link-hijacking

Detect broken link hijacking and subdomain takeover risks in web applications.

4|Updated Apr 28, 2026
One-click install
npx skills add https://github.com/braydos-h/BreachPilot --skill exploiting-broken-link-hijacking-braydos-h
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: exploiting-broken-link-hijacking
Source: https://github.com/braydos-h/BreachPilot/tree/main/skills/exploiting-broken-link-hijacking
Command: npx skills add https://github.com/braydos-h/BreachPilot --skill exploiting-broken-link-hijacking-braydos-h

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires requests, and includes scripts (resource) and references (resource) components.

What problem does it solve? Web applications often reference external resources—domains, scripts, cloud buckets, and subdomains—that expire or get decommissioned, allowing attackers to claim them and serve malicious content under the target's trust. This Skill finds those dangling references before attackers do. ## Core Features & Use Cases - Dead Link Discovery: Crawl target sites with broken-link-checker, curl, and Burp Suite to extract external links, scripts, and CSS references, then identify dead or unresolvable resources. - Takeover Detection: Check dangling CNAME records, unclaimed S3 buckets, GitHub Pages, Heroku, Azure, and Shopify endpoints using subjack, nuclei, and service-specific fingerprinting. - Python Scanning Agent: Run the included agent.py script to extract external links, check their HTTP status, and flag hijackable platforms with severity ratings in a JSON report. - Use Case: During a bug bounty assessment, scan a target's pages, discover that an analytics JavaScript file loads from an expired domain, and document the full-XSS impact in a structured report. ## Quick Start Run the agent script with --url pointing at your authorized target to generate a JSON report of hijackable external links.

Frequently Asked Questions about exploiting-broken-link-hijacking

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I detect broken link hijacking on a website?▼

Crawl the site with broken-link-checker or the included Python agent to extract external links, then check each for 404 responses or DNS failures. Links pointing to unregistered domains or unclaimed platform resources are flagged as hijackable with severity ratings.

What tools find subdomain takeover vulnerabilities?▼

subjack performs automated takeover detection using fingerprint databases, while nuclei uses takeover templates against enumerated subdomains. Manual checks involve dig for dangling CNAME records and curl to match service-specific error messages like "NoSuchBucket" or "No such app".

Which cloud services are vulnerable to subdomain takeover?▼

Common vulnerable services include AWS S3 (NoSuchBucket), GitHub Pages, Heroku, Azure Blob Storage, and Shopify. Each returns a distinctive error message when the underlying resource is unclaimed but the DNS CNAME still points to it.

Does the scanning agent work without the requests library?▼

No, the agent.py script requires the Python requests library to fetch pages and check link status. Without it, the script reports that requests is unavailable and returns no findings.

What is the impact of a hijacked external JavaScript link?▼

A hijacked external script gives the attacker full cross-site scripting on every page that loads it, since the code executes under the target's origin. Hijacked CSS enables defacement and data exfiltration, while hijacked subdomains enable phishing and cookie theft.