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Introduction
Regular expressions (Regex) are a powerful tool for cybersecurity professionals, especially when hunting for leaked credentials or sensitive data in JavaScript files. A well-crafted Regex pattern can help automate the discovery of API keys, passwords, and other critical information exposed in web applications. In this article, we’ll break down an advanced Regex pattern designed for leaked data hunting and explore how to leverage it effectively.
Learning Objectives
- Understand how Regex can be used to detect leaked credentials in JS files.
- Learn how to customize Regex patterns for different keyword variations.
- Discover additional tools and communities for bug bounty hunters.
1. Regex for Leaked Data Hunting
Verified Regex Pattern
Key[-_]?Word\s[:=\"'\s]\s([a-zA-Z0-9_-]{8,}[^'\":;\s,])
Step-by-Step Explanation
1. `Key[-_]?Word` – Matches variations like KeyWord, Key-Word, or Key_Word.
2. `\s[:=\”‘\s]` – Accounts for different separators (:, =, ", ', or whitespace).
3. `([a-zA-Z0-9_\-]{8,}[^’\”:;\s,])` – Captures the actual value:
– `[a-zA-Z0-9_\-]{8,}` ensures it’s at least 8 characters long (common for API keys).
– `[^’\”:;\s,]` excludes trailing delimiters.
Usage Example:
grep -E "Key[-_]?Word\s[:=\"'\s]\s([a-zA-Z0-9_-]{8,}[^'\":;\s])" target.js
2. Customizing Regex for Different Keywords
Modified Regex for API Keys
API[-_]?Key\s[:=\"'\s]\s([a-zA-Z0-9_-]{20,}[^'\":;\s,])
How to Use It
- Adjust the keyword (e.g., `API[-_]?Key` for API keys).
- Modify the length (
{20,}for longer keys). - Run with `grep` or a script to scan multiple files:
grep -r -E "API[-_]?Key\s[:=\"'\s]\s([a-zA-Z0-9_-]{20,}[^'\":;\s])" /path/to/files
3. Automating Leaked Data Detection
Python Script for Bulk Scanning
import re
pattern = r"Key[-_]?Word\s[:=\"'\s]\s([a-zA-Z0-9_-]{8,}[^'\":;\s])"
with open("target.js", "r") as file:
matches = re.findall(pattern, file.read())
print("Found potential leaks:", matches)
Steps to Run
1. Save the script as `leak_scanner.py`.
2. Replace `”target.js”` with your file path.
3. Execute with:
python3 leak_scanner.py
4. Integrating with Burp Suite for Live Scanning
Burp Suite Extension (Bambda Script)
def processResponse(response):
body = response.getResponse().tostring()
matches = re.findall(r"Key[-_]?Word\s[:=\"'\s]\s([a-zA-Z0-9_-]{8,}[^'\":;\s])", body)
if matches:
print("Potential leak found:", matches)
How to Deploy
1. Open Burp Suite → Extensions → Bambda.
- Paste the script and enable it for traffic inspection.
5. Expanding Your Bug Hunting Toolkit
Recommended Resources
- WhatsApp Community: Join Here
- YouTube Channel: Subscribe Here
What Undercode Say
🔑 Key Takeaway 1: Regex is indispensable for efficient data leak detection, but it requires fine-tuning for accuracy.
🔑 Key Takeaway 2: Automation (Python, Burp Suite) enhances scalability in bug bounty hunting.
Analysis:
The provided Regex pattern is highly adaptable, making it useful for both beginners and advanced hunters. However, false positives can occur—always verify findings manually. Integrating Regex with tools like grep, Python, or Burp Suite streamlines the process, allowing hunters to cover more ground in less time.
Prediction
As web applications grow more complex, automated leak detection will become a standard practice in cybersecurity. Future advancements may include AI-driven Regex optimization and real-time cloud-based scanning, further reducing manual effort in bug bounty programs.
Ready to level up your security skills? Join the community and start hunting today! 🚀
IT/Security Reporter URL:
Reported By: Deepak Saini – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
