Published on February 28th, 2018📅| 0
Shellen – Interactive Shellcoding Environment, In Which You Can Easily Craft Your Shellcodes
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
How to run:
After installing shellen and all its required packages, you can run shellen just by typing the next in your terminal:
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 dsmrespectively. 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:
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:
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
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
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
syswith 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
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>
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.
||Clear the terminal screen. As usual
||Show the help message.|
||Finish the current session and quit|
Just a little bunch of pictures.