Exploiting Broken Link Hijacking

---
name: exploiting-broken-link-hijacking
description: Use when discover and exploit broken link hijacking vulnerabilities by
  identifying references to expired domains, decommissioned cloud resources, and dead
  external services that can be claimed by an attacker. Use when working with exploiting
  broken link hijacking.
domain: cybersecurity
tags:
- broken-link-hijacking
- blh
- subdomain-takeover
- dead-link
- expired-domain
- supply-chain
- external-resource
subdomain: web-application-security
version: '1.0'
author: oyi77
license: Apache-2.0
nist_csf:
- PR.PS-01
- ID.RA-01
- PR.DS-10
- DE.CM-01
category: cybersecurity
---

# Exploiting Broken Link Hijacking

## Overview

Cybersecurity skill for exploiting broken link hijacking. Follows industry best practices and security standards.

## When to Use
**Trigger phrases:**
- "exploiting broken link hijacking"
- "Discover and exploit broken link hijacking vulnerabilities by identifying refere"

- When auditing web applications for references to expired or unclaimed external resources
- During supply chain security assessments of third-party script and resource dependencies
- When testing for subdomain takeover opportunities via dangling CNAME records
- During bug bounty hunting for broken link hijacking vulnerabilities
- When assessing the security of external resource dependencies in production applications


## When NOT to Use

- When you lack proper authorization for testing
- For production systems without change management
- When the task requires legal or compliance expertise beyond technical scope


## Prerequisites
- Web crawler or spider for discovering all external links (Burp Suite Spider, Scrapy)
- DNS lookup tools for checking CNAME records and domain availability
- Domain registrar access for claiming expired domains (as proof of concept)
- Understanding of CDN and cloud service provisioning (S3, Azure Blob, GitHub Pages)
- blc (broken-link-checker) or similar tool for automated link validation
- Knowledge of services vulnerable to subdomain takeover (can-i-take-over-xyz)


> **Legal Notice:** This skill is for authorized security testing and educational purposes only. Unauthorized use against systems you do not own or have written permission to test is illegal and may violate computer fraud laws.

## Workflow

```python
# Example: IOC detection
import re

IOC_PATTERNS = {
    "ip": r"\b(?:\d{1,3}\.){3}\d{1,3}\b",
    "domain": r"\b[a-z0-9-]+\.[a-z]{2,}\b",
    "hash_md5": r"\b[a-f0-9]{32}\b",
    "hash_sha256": r"\b[a-f0-9]{64}\b",
}

def extract_iocs(text: str) -> dict:
    return {k: re.findall(v, text) for k, v in IOC_PATTERNS.items()}
```

1. **Reconnaissance** — Gather information about the target related to broken link hijacking. Identify attack surface.
2. **Vulnerability Identification** — Enumerate potential broken link hijacking weaknesses using automated and manual techniques.
3. **Exploit Development/Selection** — Choose or develop exploits targeting identified broken link hijacking vulnerabilities.
4. **Execution** — Execute the broken link hijacking test in a controlled manner with proper authorization.
5. **Post-Exploitation** — Document the impact and extent of successful exploitation.
6. **Reporting** — Write detailed findings with reproduction steps, impact assessment, and remediation guidance.

## Tools

- **Vulnerability Scanner** — Automated weakness identification
- **Exploitation Framework** — Controlled exploitation testing
- **Reporting Tool** — Findings documentation and tracking


## Process

1. **Reconnaissance** — Gather target information, identify attack surface, enumerate services
1. **Analysis/Exploitation** — Execute the technique, analyze results, document findings
1. **Reporting** — Document IOCs, write findings, provide remediation recommendations

## Verification

- [ ] All broken link hijacking procedures executed completely and documented
- [ ] Findings validated against multiple data sources
- [ ] False positives identified and filtered
- [ ] Results documented with evidence and timestamps
- [ ] Recommendations provided with risk-based prioritization

## Anti-Rationalization Table

| Rationalization | Reality |
|---|---|
| "We are too small to be targeted" | Automated attacks target everyone. Size does not matter. |
| "Security slows us down" | A breach slows you down 100x more. Build security in from the start. |
| "We will fix it after launch" | Vulnerabilities in production are exploited within hours. Fix before deploy. |