shellcodes

Custom shellcodes, free for use.

Purpose

The purpose of this repository is to store custom shellcodes that I can't seem to find via Google-searching, other open source projects, pwnlib shellcode auto-generation, etc.

Currently, this repository only contains shellcodes to execute a single command on a remote target across multiple different architectures. There are plenty of methods to write shellcode in C, however, conducting relative jumps to store strings in registers seems easier to do in assembly.

Building shellcodes

I provide a build.sh script in the root of this repository. Running it like so should provide you with an assembled shellcode for each supported architecture:

./build.sh

Using system shellcodes

The shellcodes provided are designed to execute the following command on Linux targets:

/bin/sh -c "<your command here>"

To add your command to a shellcode, run the following command from the root of this repo:

echo -ne "<your command here>" | cat src/<arch>-system.bin - > shellcode

The file shellcode will now contain the system shellcode, appended with your command.

Testing shellcodes

The provided build.sh script also compiles the loader.c ELF for each supported architecture. Given a target shellcode file, the loader ELF will read and execute your shellcode file for testing.

Contributing

Obtaining shellcode execution on a target to then execute a system command via /bin/sh has been effective enough for me, historically, to execute follow-on payloads by uploading them to the target via wget or curl. If you see the need for more complex shellcodes, feel free to submit a pull request.