Awesome
linux-injector
Utility for injecting executable code into a running process on x86/x64 Linux. It uses ptrace()
to attach to a process, then mmap()
's memory regions for the injected code, a new stack, and space for trampoline shellcode. Finally, the trampoline in the target process is used to create a new thread and execute the chosen shellcode, so the main thread is allowed to continue. This project borrows from a number of other projects and research, see References below.
Requirements
- fasm, the flat assembler
Building
With fasm installed in your PATH
, simply run:
make
Included programs and files
-
print: Test program for executing shellcode using a variety of techniques:
fork()
,clone()
, clone syscall with inline assembly. -
dummy: A trivial program for injecting into. Prints a message every second, then sleeps.
-
injector: The main program for injecting executable code into a running process. Simply provide it with the PID of the process to inject into, and the shellcode to execute:
./injector 1234 print64.bin
-
clone64.asm, clone32.asm, mmap64.asm, mmap32.asm: Shellcode stubs used by the injector.
-
print64.asm, print32.asm: Sample shellcode for printing a single line to stdout. Useful for testing the injector.
References
- Linux Threads Through a Magnifier: Local Threads
- Linux Threads Through a Magnifier: Remote Threads
- Jugaad thread injection kit
- https://sourceware.org/ml/libc-help/2009-05/msg00090.html
- Ptrace protection since Ubuntu 10.10
- Single Process Parasite: The quest for the stealth backdoor
Further work
I plan on expanding this project to be a full ELF shared library injector. While this tool could theoretically be used as-is to inject a statically-compiled, position-independent ELF library, I want to be able to parse libraries with dynamically-loaded dependencies and load those dependencies as part of the injection process. The following resources are a useful starting point:
- Injectso
- Dynamically inject a shared library into a running process on Android/ARM
- ELF file format
- The Inside Story on Shared Libraries and Dynamic Loading
Copyright (c) 2015, Dan Staples. This code is available under the GNU General Public License, version 3.