Listen to this Post
Bug bounty hunting is a rewarding yet challenging field, and diving deep into JavaScript files can often reveal hidden endpoints and sensitive information. As demonstrated by Yousuf Abdullah Fahim’s recent success on YesWeHack, thorough exploration of JavaScript files can lead to significant discoveries.
You Should Know:
1. Extracting JavaScript Files from Web Applications
Use tools like `wget` or `curl` to download all JavaScript files from a target website:
wget --recursive --no-parent --accept js https://example.com
Or use `curl` to fetch a specific file:
curl -O https://example.com/static/main.js
#### **2. Analyzing JavaScript for Hidden Endpoints**
Use `grep` to search for API endpoints, hidden paths, or sensitive keywords:
grep -rE "(api|endpoint|admin|token|auth)" *.js
For Windows users, PowerShell can be used:
Select-String -Path "*.js" -Pattern "api|endpoint|admin|token|auth"
#### **3. Using Browser DevTools for Dynamic Analysis**
- Open Chrome DevTools (
Ctrl+Shift+IorF12). - Go to the Sources tab and inspect loaded JS files.
- Use the Search function (
Ctrl+F) to look for keywords like/api/,token, orsecret.
#### **4. Automating JS Analysis with Tools**
- LinkFinder: Extracts endpoints from JS files.
python3 linkfinder.py -i https://example.com/script.js -o cli
- JS-Scan: A Node.js tool for scanning JavaScript files.
npx js-scan -u https://example.com
#### **5. Testing Discovered Endpoints**
Use `curl` or Postman to test extracted endpoints:
curl -X GET https://example.com/api/hidden-endpoint
Check for misconfigurations like:
- IDOR (Insecure Direct Object Reference)
- Unauthorized Access
- Information Disclosure
### **What Undercode Say**
Exploring JavaScript files is a goldmine for bug bounty hunters. Many developers leave debug endpoints, internal API paths, or hardcoded secrets in client-side scripts. Always:
– Deobfuscate minified JS using tools like js-beautify.
– Monitor network requests while interacting with the web app.
– Automate the process to save time.
### **Expected Output:**
A structured report of hidden endpoints, API keys, or sensitive data extracted from JavaScript files, leading to potential bug bounty rewards.
**Relevant URLs:**
(Note: The original post did not contain direct cyber/IT-related URLs, so only tool references were added.)
References:
Reported By: Oxf4h1m Alhamdulillah – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
