Shellen is an interactive shellcoding environment. If you want a handy tool to write shellcodes, then shellen may be your friend. Shellen can also be used as an assembly or disassembly tool.
keystone and capstone engines are used for all of shellen's operations.
Shellen only works on python3. python2 support may appear in the future.
First, you should install shellen's 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 problems with installing keystone-engine, then you should compile keystone-engine (see the COMPILE.md file in the keystone repository)
After installing shellen and its required packages, you can run shellen by typing the following in your terminal:
$ shellen
You can run shellen's help
command to get information about shellen's usage.
Shellen assembles and disassembles instructions, so there are two usage modes: asm and dsm respectively. There are other features which include searching syscall tables and searching for common shellcodes.
Shellen has a useful prompt that displays the current mode, OS (operating system for syscalls), and the current mode's chosen architecture. Shellen's prompt looks like this:
L:asm:x86_32 >
You can edit your input like you're typing in a terminal. Also, shellen records your command history (just type your up arrow to see your previous commands).
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 >
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 |
To assemble instuctions, type them and separate them with semicolons as shown here:
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.
Disassembling is similar to assembling. Instead, type your bytes in the 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 shellen's current mode, type this:
L:dsm:x86_32 > archs
┌────────┬────────┬─────────┬─────────┬────────┐
│ │ │ │ │ │
│ arm32 │ mips32 │ sparc32 │ systemz │ x86_16 │
│ arm64 │ mips64 │ sparc64 │ │ x86_32 │
│ arm_tb │ │ │ │ x86_64 │
└────────┴────────┴─────────┴─────────┴────────┘
If you want to change the current architecture, enter the following:
L:dsm:x86_32 > setarch arm32
[+] Architecture of dsm changed to arm32
When you create a shellcode, you will need syscalls. To lookup syscalls with shellen, type sys
and the name of your desired syscall. Shellen will produce a list of syscalls which may contain the syscall 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 │
└────────┴───────┴──────────────────────┴──────────────────────┴──────────────┴──────────────┘
sys
prints a list of possible variants for the provided syscall. The syscall table that shellen searches depends on the chosen architecture and operating system (OS). In this case, the architecture is x86_32
and the OS is Linux
.
Shellen can show you a list of common shellcodes depending on your keyword. Shellen's keyword lookup uses shell-storm.org's API (thanks to the author!) and can be used like this:
L:asm:x86_32 > shell <keyword> <count>
Note, the count
parameter isn't required. There is an image of shell <keyword> <count>
's output in the Pictures section.
Currently, shellen is only supported on Linux. If you want to add functionality for Windows or MacOS, then write an issue and I will add support.
If you find a problem/bug or something, write an issue about this problem. Also, if you think that a feature will be a nice addition to shellen, do the same -- write an issue and I will try to add your requested feature.
- 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)