injector/runner/src/main.rs
2025-04-25 21:30:11 -07:00

298 lines
9.1 KiB
Rust

use core::str;
use std::ffi::{c_void, CStr};
use std::marker::PhantomData;
use std::mem::MaybeUninit;
use std::ptr;
use std::{fs::File, io::Read};
use windows_sys::Win32::Foundation::GetLastError;
use windows_sys::Win32::System::Diagnostics::Debug;
use windows_sys::Win32::System::Diagnostics::ToolHelp::{self, PROCESSENTRY32};
use windows_sys::Win32::System::Memory;
use windows_sys::Win32::System::Threading::PROCESS_ALL_ACCESS;
use windows_sys::Win32::System::{LibraryLoader, Threading};
const LOAD_LIBRARY_A: *const c_void = LibraryLoader::LoadLibraryA as *const c_void;
const GET_PROC_ADDRESS: *const c_void = LibraryLoader::GetProcAddress as *const c_void;
fn main() {
unsafe { _main_remote() }
}
struct Reader<'a> {
phantom: PhantomData<&'a [u8]>,
ptr: *const u8,
}
impl<'a> Reader<'a> {
unsafe fn read<T: Copy>(&mut self) -> T {
let value = core::ptr::read_unaligned(self.ptr as *const T);
self.ptr = self.ptr.byte_add(core::mem::size_of::<T>());
value
}
unsafe fn read_zt(&mut self) -> &'a [u8] {
let start = self.ptr;
let mut n = 0;
while *self.ptr != 0 {
self.ptr = self.ptr.byte_add(1);
n += 1
}
self.ptr = self.ptr.byte_add(1);
n += 1; // include the null terminator
return std::slice::from_raw_parts(start, n);
}
}
struct LocalWriter {
binary: *mut u8,
base: *mut u8,
ptr: *mut u8,
}
struct Measurer {
count: usize,
}
impl Measurer {}
trait CodeGen {
unsafe fn write(&mut self, u8s: &[u8]) -> *const c_void;
unsafe fn write_ptr(&mut self, ptr: *const c_void) -> *const c_void {
let bytes = unsafe { std::mem::transmute::<*const c_void, [u8; 8]>(ptr) };
self.write(&bytes)
}
unsafe fn address_in_binary(&mut self, offset: usize) -> *const c_void;
}
impl CodeGen for LocalWriter {
unsafe fn write(&mut self, u8s: &[u8]) -> *const c_void {
let addr = self.ptr;
for u in u8s {
*self.ptr = *u;
self.ptr = self.ptr.byte_add(1);
}
self.binary.offset(addr.offset_from(self.base)) as *const c_void
}
unsafe fn address_in_binary(&mut self, offset: usize) -> *const c_void {
self.binary.byte_add(offset) as *const c_void
}
}
impl CodeGen for Measurer {
unsafe fn write(&mut self, u8s: &[u8]) -> *const c_void {
self.count += u8s.len();
return ptr::null();
}
unsafe fn address_in_binary(&mut self, _: usize) -> *const c_void {
return ptr::null();
}
}
unsafe fn write_imports(
strings: &mut impl CodeGen,
prelude: &mut impl CodeGen,
reader: &mut Reader,
) {
let entry_point = reader.read::<u32>();
println!("entry point: {}", entry_point);
// push rbp
prelude.write(&[0x55]);
// mov rbp, rsp
prelude.write(&[0x48, 0x89, 0xe5]);
// nop
prelude.write(&[0x90]);
// sub rsp, 0x20
prelude.write(&[0x48, 0x83, 0xec, 0x20]);
// windows needs 32 bytes to clobber: https://en.wikipedia.org/wiki/X86_calling_conventions#Microsoft_x64_calling_convention
loop {
let dll = reader.read_zt();
if dll.len() == 1 {
break;
}
println!("import dll: {:?}", str::from_utf8(dll).unwrap());
let library_addr = strings.write(dll);
strings.write(&[0]);
loop {
let symbol = reader.read_zt();
if symbol.len() == 1 {
break;
}
println!("import symbol: {:?}", str::from_utf8(symbol).unwrap());
let dest = reader.read::<u32>();
let symbol_addr = strings.write(symbol);
// mov rcx, library name
prelude.write(&[0x48, 0xb9]);
prelude.write_ptr(library_addr);
// mov rax, LoadLibraryA
prelude.write(&[0x48, 0xb8]);
prelude.write_ptr(LOAD_LIBRARY_A);
// call rax
prelude.write(&[0xff, 0xd0]);
// mov rcx, rax
prelude.write(&[0x48, 0x89, 0xc1]);
// mov rdx, symbol name
prelude.write(&[0x48, 0xba]);
prelude.write_ptr(symbol_addr);
// mov rax, GetProcAddress
prelude.write(&[0x48, 0xb8]);
prelude.write_ptr(GET_PROC_ADDRESS);
// call rax
prelude.write(&[0xff, 0xd0]);
// mov [import address], rax
prelude.write(&[0x48, 0xa3]);
let addr = prelude.address_in_binary(dest as usize);
prelude.write_ptr(addr);
}
}
// mov rax, original entry point
prelude.write(&[0x48, 0xb8]);
let addr = prelude.address_in_binary(entry_point as usize);
// let addr = load_library_a;
prelude.write_ptr(addr);
// call rax
prelude.write(&[0xff, 0xd0]);
// leave, ret
prelude.write(&[0xc9, 0xc3]);
}
unsafe fn write_starting_state(binary: *mut u8, reader: &mut Reader) {
let length = reader.read::<u32>() as usize;
let ptr = reader.ptr;
println!("length: {:?}", length);
binary.copy_from(ptr, length);
}
unsafe fn _main_remote() {
let mut input = File::open("binaries/main.dat").unwrap();
let mut buf: Vec<u8> = vec![];
let _ = input.read_to_end(&mut buf).unwrap();
let mut measuring_reader = Reader {
phantom: PhantomData,
ptr: buf.as_ptr(),
};
let mut string_measurer = Measurer { count: 0 };
let mut code_measurer = Measurer { count: 0 };
write_imports(
&mut string_measurer,
&mut code_measurer,
&mut measuring_reader,
);
let starting_state_len = measuring_reader.read::<u32>() as usize;
println!("starting state len: {}", starting_state_len);
// string_measurer.round_up();
// code_measurer.round_up();
// TODO: Alignment
let Some(victim) = identify_victim() else {
println!("couldn't find victim");
return;
};
let remote = Threading::OpenProcess(PROCESS_ALL_ACCESS, 0, victim);
if remote == ptr::null_mut() {
println!("got null");
return;
}
let total_size = starting_state_len as usize + string_measurer.count + code_measurer.count;
let remote_address_space = Memory::VirtualAllocEx(
remote,
ptr::null(),
total_size,
Memory::MEM_COMMIT | Memory::MEM_RESERVE,
Memory::PAGE_EXECUTE_READWRITE,
);
let local_address_space = Memory::VirtualAlloc(
ptr::null(),
total_size,
Memory::MEM_COMMIT | Memory::MEM_RESERVE,
Memory::PAGE_EXECUTE_READWRITE,
);
let mut loading_reader = Reader {
phantom: PhantomData,
ptr: buf.as_ptr(),
};
let strings = local_address_space.byte_add(starting_state_len);
let prelude = strings.byte_add(string_measurer.count);
let mut strings_writer = LocalWriter {
binary: remote_address_space as *mut u8,
base: local_address_space as *mut u8,
ptr: strings as *mut u8,
};
let mut prelude_writer = LocalWriter {
binary: remote_address_space as *mut u8,
base: local_address_space as *mut u8,
ptr: prelude as *mut u8,
};
println!("writing imports");
write_imports(
&mut strings_writer,
&mut prelude_writer,
&mut loading_reader,
);
println!("writing starting state");
write_starting_state(local_address_space as *mut u8, &mut loading_reader);
println!("done!");
println!("error: {}", GetLastError());
println!(
"Copying memory to foreign process (at {:?} from {:?} get {:?})",
remote_address_space, local_address_space, total_size
);
Debug::WriteProcessMemory(
remote,
remote_address_space,
local_address_space,
total_size,
ptr::null_mut(),
);
println!("error: {}", GetLastError());
println!("Creating remote thread");
let entry_point =
remote_address_space.byte_offset(prelude.byte_offset_from(local_address_space));
println!("Entry point: {:?}", entry_point);
Threading::CreateRemoteThread(
remote,
ptr::null(),
0,
Some(std::mem::transmute::<
*mut c_void,
unsafe extern "system" fn(*mut c_void) -> u32,
>(entry_point)),
ptr::null(),
0,
ptr::null_mut(),
);
println!("error: {}", GetLastError());
println!("Done!");
}
unsafe fn identify_victim() -> Option<u32> {
let snapshot = ToolHelp::CreateToolhelp32Snapshot(ToolHelp::TH32CS_SNAPPROCESS, 0);
let mut entry: MaybeUninit<PROCESSENTRY32> = MaybeUninit::uninit();
entry.assume_init_mut().dwSize = std::mem::size_of::<PROCESSENTRY32>() as u32;
let mut process = ToolHelp::Process32First(snapshot, entry.as_mut_ptr());
println!("error: {}; process: {}", GetLastError(), process);
while process != 0 {
let entry_ref = entry.assume_init_ref();
let name = CStr::from_ptr(entry_ref.szExeFile.as_ptr());
println!("peeking: {:?}", name);
if name.eq(CStr::from_bytes_with_nul_unchecked(b"notepad.exe\x00")) {
return Some(entry_ref.th32ProcessID);
}
process = ToolHelp::Process32Next(snapshot, entry.as_mut_ptr());
}
return None;
}