WebAssembly_Shellcode

WebAssembly Shellcode 🦀

• Overview
• Usage
• References

Overview

This project focuses on demonstrating how we can execute shellcode using WebAssembly. It is often used for shellcode evasion.

Usage

First, access the "shellcode assembly" directory and, if you wish, replace your shellcode with a specific one, in my case, it is configured to run notepad.exe. Then run the command:

wasm-pack build --target bundler

It will generate a file called "shellcode_webassembly_bg.wasm" in the "/pkg" directory, then use the command to convert it to ".wat":

wasm2wat pkg/shellcode_webassembly_bg.wasm -o shell.wat

That concludes the shellcode generation part. Now, upload your shell.wat file to the directory. Next, we'll execute the file, which in the project is called "execute_shellcode", and run the command directly:

cargo run --release

Or by running the binary directly after generation:

target/release/execute_shellcode.exe

Remember that we can embed the shellcode inside the binary, but to make it more didactic we prefer to leave the "shell.wat" file separate from the binary.

References

https://balwurk.com/shellcode-evasion-using-webassembly-and-rust/