JStillery

JStillery Description

JStillery is an advanced JavaScript deobfuscator via Partial Evaluation. Through the use of various techniques, obfuscated JavaScript becomes more readable.

JStillery is designed both as a program for working on a personal computer and as an online service from the author.

Homepage: https://github.com/mindedsecurity/JStillery

Author: Stefano Di Paola

License: GPLv3

JStillery Help

Usage:

jstillery /path/to/file

The program has no options.

It supports standard input as well.

The program has a built-in web server and web interface.

JStillery Usage Example

Deobfuscate the /var/www/html/dvwa/vulnerabilities/javascript/source/high.js file:

./jstillery_cli.js /var/www/html/dvwa/vulnerabilities/javascript/source/high.js

Deobfuscation of a string “a= String.fromCharCode(41);b=a”.

echo 'a= String.fromCharCode(41);b=a' | ./jstillery_cli.js

How to install JStillery

Installation on Kali Linux

sudo apt install npm
git clone https://github.com/mindedsecurity/JStillery
cd JStillery
sudo npm install

To compile the server:

npm run build_server

To start the server:

npm run start_server

After that, the web interface will be available at http://localhost:3001

Installation on Debian, Linux Mint, Ubuntu

sudo apt install git npm
git clone https://github.com/mindedsecurity/JStillery
cd JStillery
sudo npm install

To compile the server:

npm run build_server

To start the server:

npm run start_server

After that, the web interface will be available at http://localhost:3001

Installation on BlackArch

The program is pre-installed on BlackArch.

sudo pacman -S jstillery

JStillery online service

It is not necessary to install the program on a computer, the author has created a page that can de-obfuscate JavaScript code: https://mindedsecurity.github.io/jstillery/

JStillery Screenshots

JStillery Tutorials

• How to deobfuscate JavaScript code
• How to see JavaScript code written using unprintable characters
• JavaScript Attacks