SHELL-JS

A lightweight,shellcode loader written in js for Windows that reads shellcode from a local .h file (in \xAA\xBB... C-header format), allocates executable memory, and runs it in a new thread.

Educational / Red Team / Research use only.

Features

• Reads shellcode from local file (no network dependency)
• Supports two input formats:
  • Classic C header style: \xAA\xBB\xCC... (.h, .c, .txt, etc.)
  • Raw binary shellcode (.bin, .raw, .sc)
• Optional 1-byte XOR decoding with --xor-key
• Allocates memory using VirtualAlloc
• Attempts stealthier RX (PAGE_EXECUTE_READ) protection first
• Falls back to RWX (PAGE_EXECUTE_READWRITE) if RX fails
• Executes shellcode in a new thread via CreateThread
• Optional wait timeout for the thread (--wait) — supports non-blocking mode
• Clean help message with --help / -h
• Minimal dependencies (koffi + Node.js)

Requirements

• Windows operating system
• Node.js ≥ 18
• npm

Installation

# 1. Clone the repo
git clone https://github.com/00nx/shell-js.git
cd shell-js

# 2. Install dep
npm install koffi

usage

Usage: node inject.js <file> [options]
Options:
  --xor-key <number>   XOR decode shellcode with 1-byte key (0–255)
  --wait <ms>          WaitForSingleObject timeout (default: infinite, 0 = non-blocking)
  --help               Show this help

Basic usage (C header file)

node inject.js payload.h

Specify raw binary shellcode

node inject.js beacon.bin

With XOR decoding (key = 0x5A)

node inject.js payload.h --xor-key 0x5A node inject.js payload.bin -k 90

Run and exit immediately (non-blocking)

node inject.js shellcode.bin --wait 0

Wait max 10 seconds for thread to finish

node inject.js staged.bin --wait 10000

Show help

node inject.js --help node inject.js bytes.h