Shellen is an interactive shellcoding environment. If you want a handy tool to write shellcodes, then shellen may be your friend. Also, it can be used just as assembly/disassembly tool.
It uses keystone and capstone engines for all provided operations.
Shellen works only on python3. Maybe support for python2 will appear in the future.
First of all, install the next dependencies:
$ sudo apt-get install cmake python3-dev python3-setuptools
You can install the stable version of shellen using pip3
:
$ sudo pip3 install shellen
Or if you already have all required packages (see Requirements):
$ python3 setup.py install
If you have any trouble with installing keystone-engine, then you should compile it by yourself (see the COMPILE.md file in the keystone repository)
After installing shellen and all its required packages, you can run shellen just by typing the next in your terminal:
$ shellen
There is the help
command inside the tool, that will explain almost everything.
Shellen was created for assembling and disassembling instructions, so there are two modes of using the tool: asm and dsm respectively. Of course, there are some other possibilities like syscalls tables, common shellcodes and other.
If you find a problem/bug or something, then just write an issue about this problem. Also, if you think, that some feature will be nice to use in shellen, then do the same -- write an issue and I will try to add this feature.
It also has a usefull prompt, displaying current mode, OS (Operating System for syscalls) and chosen architecture exactly for this mode. It looks as follows:
L:asm:x86_32 >
You can edit your input like you're typing in a terminal. Also, it has a history of commands (just type up arrow to see them).
L
is the shortened name of Linux
in the prompt. Below listed all other OS names:
L
is LinuxW
is WindowsM
is MacOS
If you want to change OS, then type setos [linux/windows/macos]
as follows:
L:asm:x86_32 > setos windows
[+] OS changed to windows.
To change current mode, enter asm
or dsm
in the prompt.
L:dsm:arm32 > asm
[+] Changed to asm (assembly) mode
L:asm:x86_32 > dsm
[+] Changed to dsm (disassembly) mode
L:dsm:arm32 >
To assembly instuctions, type them separated by colons as follows:
L:asm:x86_32 > mov edx, eax; xor eax, eax; inc edx; int 80;
[+] Bytes count: 7
Raw bytes: "\x89\xc2\x31\xc0\x42\xcd\x50"
Hex string: "89c231c042cd50"
If your assembled bytes contain a null byte, then shellen will tell you about this.
It works exactly as assembling. Type your bytes in the input prompt and see the result!
L:dsm:x86_32 > 89c231c042cd50
0x00080000: mov edx, eax
0x00080002: xor eax, eax
0x00080004: inc edx
0x00080005: int 0x50
asm
and dsm
modes work for different architectures. To see a list of available architectures for a current mode, type this:
L:dsm:x86_32 > archs
┌────────┬────────┬─────────┬─────────┬────────┐
│ │ │ │ │ │
│ arm32 │ mips32 │ sparc32 │ systemz │ x86_16 │
│ arm64 │ mips64 │ sparc64 │ │ x86_32 │
│ arm_tb │ │ │ │ x86_64 │
└────────┴────────┴─────────┴─────────┴────────┘
And if you want to change current architecture, enter follow:
L:dsm:x86_32 > setarch arm32
[+] Architecture of dsm changed to arm32
It's apparent that in process of crafting a shellcode you will be needed syscalls. So, shellen will help you with that. Just type sys
with a name of desired syscall and shellen will show you a list of possible syscalls you were looking for.
L:asm:x86_32 > sys open
┌────────┬───────┬──────────────────────┬──────────────────────┬──────────────┬──────────────┐
│ name │ eax │ ebx │ ecx │ edx │ esi │
├────────┼───────┼──────────────────────┼──────────────────────┼──────────────┼──────────────┤
│ open │ 0x05 │ const char *filename │ int flags │ umode_t mode │ - │
│ openat │ 0x127 │ int dfd │ const char *filename │ int flags │ umode_t mode │
└────────┴───────┴──────────────────────┴──────────────────────┴──────────────┴──────────────┘
This prints possible variants of syscall depending on entered pattern. Syscall table for searching depends on chosen architecture and OS (Operating System). In this case it's x86_32
and Linux
.
Shellen can show you a list of common shellcodes depending on your keyword. The example of using placed in Pictures
section. It uses API of shell-storm.org site (thanks to the author!). You can use it like this:
L:asm:x86_32 > shell <keyword> <count>
Actually, count
parameter isn't required.
It was assumed that there will be several OSs (Linux, Windows and MacOS), but right now supported only Linux. If you want to add functionality for Windows or MacOS, then write an issue and I will add it.
Command | Description |
---|---|
clear |
Clear the terminal screen. As usual cls on Windows or clear on *nix systems. |
help |
Show the help message. |
quit,q,exit |
Finish the current session and quit |
- Assembling
- Disassembling
- Syscalls lists
- Database of common shellcodes
- Fix readline (right now it works ugly)
- Add ROP builder
- Add editing an assembly code in multiple lines
Just a little bunch of pictures. (They are outdated because of adding different features)