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vmassembler/src/main.cpp

480 lines
18 KiB

#include <Windows.h>
#include <cli-parser.hpp>
#include <fstream>
#include <iostream>
#include <sstream>
#include <transform.hpp>
#include <xtils.hpp>
#include "compiler.h"
#include "parser.h"
#include "parser.tab.h"
#include "vmasm.hpp"
#include "vmprofiler.hpp"
extern FILE *yyin;
extern "C" int yywrap()
{
return 1;
}
void yyerror( char *msg )
{
std::printf( "[!] parsing failure: %s\n", msg );
}
template < typename... Args > std::string string_format( const std::string &format, Args... args )
{
int size_s = std::snprintf( nullptr, 0, format.c_str(), args... ) + 1;
auto size = static_cast< size_t >( size_s );
auto buf = std::make_unique< char[] >( size );
std::snprintf( buf.get(), size, format.c_str(), args... );
return std::string( buf.get(), buf.get() + size - 1 );
}
static void open_binary_file( const std::string &file, std::vector< uint8_t > &data )
{
std::ifstream fstr( file, std::ios::binary );
fstr.unsetf( std::ios::skipws );
fstr.seekg( 0, std::ios::end );
const auto file_size = fstr.tellg();
fstr.seekg( NULL, std::ios::beg );
data.reserve( static_cast< uint32_t >( file_size ) );
data.insert( data.begin(), std::istream_iterator< uint8_t >( fstr ), std::istream_iterator< uint8_t >() );
}
std::string gen_code( std::vector< vm::compiled_label_data > &labels, std::string image_path, vm::ctx_t vmctx )
{
std::string result, raw_file_array;
std::vector< std::uint8_t > raw_file;
open_binary_file( image_path, raw_file );
for ( auto idx = 0u; idx < raw_file.size(); ++idx )
raw_file_array.append( string_format( "0x%x, ", raw_file[ idx ] ) );
result.append( "#pragma once\n"
"#pragma section( \".xmp2\" )\n"
"#pragma comment( linker, \"/section:.xmp2,RWE\" ) \n\n" );
result.append( "namespace vm\n"
"{\n" );
result.append( R"( using u8 = unsigned char;
using s8 = signed char;
using u16 = unsigned short;
using s16 = signed short;
using u32 = unsigned int;
using s32 = signed int;
using u64 = unsigned long long;
using s64 = signed long long;
using __vmcall_t = void* (*)(...);
constexpr u8 IMAGE_DIRECTORY_ENTRY_BASERELOC = 8;
constexpr u8 IMAGE_REL_BASED_ABSOLUTE = 0;
constexpr u8 IMAGE_REL_BASED_DIR64 = 10;
typedef struct _IMAGE_DOS_HEADER
{
/* 0x0000 */ unsigned short e_magic;
/* 0x0002 */ unsigned short e_cblp;
/* 0x0004 */ unsigned short e_cp;
/* 0x0006 */ unsigned short e_crlc;
/* 0x0008 */ unsigned short e_cparhdr;
/* 0x000a */ unsigned short e_minalloc;
/* 0x000c */ unsigned short e_maxalloc;
/* 0x000e */ unsigned short e_ss;
/* 0x0010 */ unsigned short e_sp;
/* 0x0012 */ unsigned short e_csum;
/* 0x0014 */ unsigned short e_ip;
/* 0x0016 */ unsigned short e_cs;
/* 0x0018 */ unsigned short e_lfarlc;
/* 0x001a */ unsigned short e_ovno;
/* 0x001c */ unsigned short e_res[ 4 ];
/* 0x0024 */ unsigned short e_oemid;
/* 0x0026 */ unsigned short e_oeminfo;
/* 0x0028 */ unsigned short e_res2[ 10 ];
/* 0x003c */ long e_lfanew;
} IMAGE_DOS_HEADER, *PIMAGE_DOS_HEADER; /* size: 0x0040 */
typedef struct _IMAGE_FILE_HEADER
{
/* 0x0000 */ unsigned short Machine;
/* 0x0002 */ unsigned short NumberOfSections;
/* 0x0004 */ unsigned long TimeDateStamp;
/* 0x0008 */ unsigned long PointerToSymbolTable;
/* 0x000c */ unsigned long NumberOfSymbols;
/* 0x0010 */ unsigned short SizeOfOptionalHeader;
/* 0x0012 */ unsigned short Characteristics;
} IMAGE_FILE_HEADER, *PIMAGE_FILE_HEADER; /* size: 0x0014 */
typedef struct _IMAGE_DATA_DIRECTORY
{
/* 0x0000 */ unsigned long VirtualAddress;
/* 0x0004 */ unsigned long Size;
} IMAGE_DATA_DIRECTORY, *PIMAGE_DATA_DIRECTORY; /* size: 0x0008 */
typedef struct _IMAGE_OPTIONAL_HEADER64
{
/* 0x0000 */ unsigned short Magic;
/* 0x0002 */ unsigned char MajorLinkerVersion;
/* 0x0003 */ unsigned char MinorLinkerVersion;
/* 0x0004 */ unsigned long SizeOfCode;
/* 0x0008 */ unsigned long SizeOfInitializedData;
/* 0x000c */ unsigned long SizeOfUninitializedData;
/* 0x0010 */ unsigned long AddressOfEntryPoint;
/* 0x0014 */ unsigned long BaseOfCode;
/* 0x0018 */ unsigned __int64 ImageBase;
/* 0x0020 */ unsigned long SectionAlignment;
/* 0x0024 */ unsigned long FileAlignment;
/* 0x0028 */ unsigned short MajorOperatingSystemVersion;
/* 0x002a */ unsigned short MinorOperatingSystemVersion;
/* 0x002c */ unsigned short MajorImageVersion;
/* 0x002e */ unsigned short MinorImageVersion;
/* 0x0030 */ unsigned short MajorSubsystemVersion;
/* 0x0032 */ unsigned short MinorSubsystemVersion;
/* 0x0034 */ unsigned long Win32VersionValue;
/* 0x0038 */ unsigned long SizeOfImage;
/* 0x003c */ unsigned long SizeOfHeaders;
/* 0x0040 */ unsigned long CheckSum;
/* 0x0044 */ unsigned short Subsystem;
/* 0x0046 */ unsigned short DllCharacteristics;
/* 0x0048 */ unsigned __int64 SizeOfStackReserve;
/* 0x0050 */ unsigned __int64 SizeOfStackCommit;
/* 0x0058 */ unsigned __int64 SizeOfHeapReserve;
/* 0x0060 */ unsigned __int64 SizeOfHeapCommit;
/* 0x0068 */ unsigned long LoaderFlags;
/* 0x006c */ unsigned long NumberOfRvaAndSizes;
/* 0x0070 */ struct _IMAGE_DATA_DIRECTORY DataDirectory[ 16 ];
} IMAGE_OPTIONAL_HEADER64, *PIMAGE_OPTIONAL_HEADER64; /* size: 0x00f0 */
typedef struct _IMAGE_NT_HEADERS64
{
/* 0x0000 */ unsigned long Signature;
/* 0x0004 */ struct _IMAGE_FILE_HEADER FileHeader;
/* 0x0018 */ struct _IMAGE_OPTIONAL_HEADER64 OptionalHeader;
} IMAGE_NT_HEADERS64, *PIMAGE_NT_HEADERS64; /* size: 0x0108 */
typedef struct _IMAGE_SECTION_HEADER
{
/* 0x0000 */ unsigned char Name[ 8 ];
union
{
union
{
/* 0x0008 */ unsigned long PhysicalAddress;
/* 0x0008 */ unsigned long VirtualSize;
}; /* size: 0x0004 */
} /* size: 0x0004 */ Misc;
/* 0x000c */ unsigned long VirtualAddress;
/* 0x0010 */ unsigned long SizeOfRawData;
/* 0x0014 */ unsigned long PointerToRawData;
/* 0x0018 */ unsigned long PointerToRelocations;
/* 0x001c */ unsigned long PointerToLinenumbers;
/* 0x0020 */ unsigned short NumberOfRelocations;
/* 0x0022 */ unsigned short NumberOfLinenumbers;
/* 0x0024 */ unsigned long Characteristics;
} IMAGE_SECTION_HEADER, *PIMAGE_SECTION_HEADER; /* size: 0x0028 */
typedef struct _IMAGE_BASE_RELOCATION
{
unsigned int VirtualAddress;
unsigned int SizeOfBlock;
} IMAGE_BASE_RELOCATION, *PIMAGE_BASE_RELOCATION;)" );
result.append( "\n\n\ttemplate < class T, class U > struct _pair_t\n"
"\t{\n"
"\t\tT first;\n"
"\t\tU second;\n"
"\t};\n\n" );
result.append( string_format( "\tconstexpr auto entry_rva = 0x%x;\n\n", vmctx.vm_entry_rva ) );
result.append( "\tenum class calls : u32\n"
"\t{\n" );
for ( auto idx = 0u; idx < labels.size(); ++idx )
result.append( string_format( "\t\t%s = 0x%x,\n", labels[ idx ].label_name, labels[ idx ].enc_alloc_rva ) );
result.append( "\t};\n\n" );
result.append( string_format( "\tinline _pair_t< u8, calls > call_map[%d] = \n"
"\t{\n",
labels.size() ) );
for ( auto idx = 0u; idx < labels.size(); ++idx )
result.append( string_format( "\t\t{ %d, calls::%s },\n", idx, labels[ idx ].label_name.c_str() ) );
result.append( "\t};\n\n" );
result.append( string_format( "\t__declspec(align(1)) struct _gen_data\n"
"\t{\n"
"\t\tu8 bin[%d] =\n"
"\t\t{\n"
"\t\t\t%s\n",
raw_file_array.size(), raw_file_array.c_str() ) );
result.append( "\t\t};\n\n" );
result.append( string_format( "\t\tu8 map_area[0x%x];\n\n", vmctx.image_size ) );
for ( auto &label : labels )
{
result.append( string_format( "\t\tu8 __%s_vinstrs[%d] =\n", label.label_name.c_str(), label.vinstrs.size() ) );
result.append( "\t\t{\n\t\t\t" );
for (auto& byte : label.vinstrs)
result.append( string_format( "0x%x, ", byte ) );
result.append( "\n\t\t};\n\n" );
}
result.append( string_format( "\t\tu8 __vmcall_shell_code[%d][15] =\n"
"\t\t{\n",
labels.size() ) );
for ( auto idx = 0u; idx < labels.size(); ++idx )
{
std::string jmp_code;
// two push instructions...
for ( auto i = 0u; i < 2; ++i )
{
jmp_code.append( "0x68, " ); // push opcode...
for ( auto _idx = 0u; _idx < 4; ++_idx )
jmp_code.append( "0x0, " );
}
// one jmp instruction...
jmp_code.append( "0xE9, " );
for ( auto i = 0u; i < 4; ++i )
jmp_code.append( "0x0, " );
result.append( string_format( "\t\t\t{ %s },\n", jmp_code.c_str() ) );
}
result.append( "\t\t};\n\n" );
result.append( R"( bool init()
{
static const auto _memcpy = []( void *dest, const void *src, size_t len ) -> void * {
char *d = ( char * )dest;
const char *s = ( char * )src;
while ( len-- )
*d++ = *s++;
return dest;
};
const auto dos_header = reinterpret_cast< IMAGE_DOS_HEADER * >( bin );
const auto nt_headers = reinterpret_cast< PIMAGE_NT_HEADERS64 >( bin + dos_header->e_lfanew );
_memcpy( map_area, bin, nt_headers->OptionalHeader.SizeOfHeaders );
auto sections = reinterpret_cast< PIMAGE_SECTION_HEADER >( ( u8 * )&nt_headers->OptionalHeader +
nt_headers->FileHeader.SizeOfOptionalHeader );
// map sections...
for ( u32 i = 0; i < nt_headers->FileHeader.NumberOfSections; ++i )
{
PIMAGE_SECTION_HEADER section = &sections[ i ];
_memcpy( ( void * )( map_area + section->VirtualAddress ),
( void * )( bin + section->PointerToRawData ), section->SizeOfRawData );
}
// handle relocations...
const auto reloc_dir = &nt_headers->OptionalHeader.DataDirectory[ IMAGE_DIRECTORY_ENTRY_BASERELOC ];
if ( reloc_dir->VirtualAddress )
{
auto reloc = reinterpret_cast< IMAGE_BASE_RELOCATION * >( map_area + reloc_dir->VirtualAddress );
for ( auto current_size = 0u; current_size < reloc_dir->Size; )
{
u32 reloc_count = ( reloc->SizeOfBlock - sizeof( IMAGE_BASE_RELOCATION ) ) / sizeof( u16 );
u16 *reloc_data = ( u16 * )( ( u8 * )reloc + sizeof( IMAGE_BASE_RELOCATION ) );
u8 *reloc_base = map_area + reloc->VirtualAddress;
for ( auto idx = 0; idx < reloc_count; ++idx, ++reloc_data )
{
u16 data = *reloc_data;
u16 type = data >> 12;
u16 offset = data & 0xFFF;
switch ( type )
{
case IMAGE_REL_BASED_ABSOLUTE:
break;
case IMAGE_REL_BASED_DIR64:
{
u64 *rva = ( u64 * )( reloc_base + offset );
*rva = ( u64 )( map_area + ( *rva - nt_headers->OptionalHeader.ImageBase ) );
break;
}
default:
break;
}
}
current_size += reloc->SizeOfBlock;
reloc = ( IMAGE_BASE_RELOCATION * )reloc_data;
}
}
// fix shellcode up...
for ( auto idx = 0u; idx < ( sizeof( __vmcall_shell_code ) / 15 ); ++idx )
{
// first push encrypted rva value...
*reinterpret_cast< u32 * >( &__vmcall_shell_code[ idx ][ 1 ] ) =
static_cast< u32 >( call_map[ idx ].second );
// second push encrypted rva value...
*reinterpret_cast< u32 * >( &__vmcall_shell_code[ idx ][ 6 ] ) =
static_cast< u32 >( call_map[ idx ].second );
// signed rip relative rva to vm entry...
*reinterpret_cast< u32 * >( &__vmcall_shell_code[ idx ][ 11 ] ) = reinterpret_cast< s32 >(
( map_area - ( reinterpret_cast< u64 >( &__vmcall_shell_code[ idx ] ) + 15 ) ) + entry_rva );
}
return true; // only a bool so i can use static/call init only once...
})" );
result.append( "\n\t};\n\n" );
result.append( "\t__declspec(allocate(\".xmp2 \")) inline _gen_data gen_data;\n\n" );
result.append( R"( template < calls e_call, class T, class ... Ts > auto call(const Ts... args) -> T
{
static auto __init_result = gen_data.init();
__vmcall_t vmcall = nullptr;
for ( auto idx = 0u; idx < sizeof( call_map ) / sizeof( _pair_t< u8, calls > ); ++idx )
if ( call_map[ idx ].second == e_call )
vmcall = reinterpret_cast< __vmcall_t >( &gen_data.__vmcall_shell_code[ idx ] );
return reinterpret_cast< T >( vmcall( args... ) );
})" );
result.append( "\n}" );
return result;
}
int __cdecl main( int argc, const char *argv[] )
{
argparse::argument_parser_t argp( "vmassembler", "virtual instruction assembler" );
argp.add_argument()
.names( { "--input", "--in" } )
.description( "path to a vasm file to be assembled..." )
.required( true );
argp.add_argument().names( { "--vmpbin", "--bin" } ).description( "path to protected binary..." ).required( true );
argp.add_argument().names( { "--vmentry", "--entry" } ).description( "rva to vm entry..." ).required( true );
argp.add_argument().names( { "--out", "--output" } ).description( "output file name and path..." ).required( true );
argp.enable_help();
auto err = argp.parse( argc, argv );
if ( err )
{
std::cout << err << std::endl;
return -1;
}
if ( argp.exists( "help" ) )
{
argp.print_help();
return 0;
}
//
// set yyin to the vasm file...
//
if ( ( yyin = fopen( argp.get< std::string >( "input" ).c_str(), "r" ) ) == nullptr )
{
std::printf( "[!] failed to open vasm file...\n" );
return -1;
}
//
// parse vasm file for all of the instructions...
//
yyparse();
std::printf( "[+] finished parsing vasm file...\n" );
//
// init vm variables...
//
const auto module_base = reinterpret_cast< std::uintptr_t >(
LoadLibraryExA( argp.get< std::string >( "vmpbin" ).c_str(), NULL, DONT_RESOLVE_DLL_REFERENCES ) );
const auto vm_entry_rva = std::strtoull( argp.get< std::string >( "vmentry" ).c_str(), nullptr, 16 );
const auto image_base = xtils::um_t::get_instance()->image_base( argp.get< std::string >( "vmpbin" ).c_str() );
const auto image_size = NT_HEADER( module_base )->OptionalHeader.SizeOfImage;
vm::ctx_t vmctx( module_base, image_base, image_size, vm_entry_rva );
if ( !vmctx.init() )
{
std::printf( "> failed to init vmctx... make sure all arguments are valid\n"
"and that the binary you are providing is unpacked and protected\n"
"by VMProtect 2...\n" );
return -1;
}
std::printf( "> flattened and deobfuscated vm entry...\n" );
vm::util::print( vmctx.vm_entry );
std::printf( "> extracted calc jmp from vm entry...\n" );
vm::util::print( vmctx.calc_jmp );
vm::compiler_t compiler( &vmctx );
//
// encode virtual instructions...
//
auto virt_labels = compiler.encode();
std::printf( "[+] finished encoding... encoded instructions below...\n" );
for ( auto &label : *virt_labels )
{
for ( const auto &vinstr : label.vinstrs )
{
if ( vinstr.imm_size )
std::printf( "> 0x%x - 0x%x\n", vinstr.vm_handler, vinstr.operand );
else
std::printf( "> 0x%x\n", vinstr.vm_handler );
}
}
//
// encrypt virtual instructions...
//
auto compiled_labels = compiler.encrypt();
std::printf( "[+] finished encrypting... encrypted labels below...\n" );
for ( const auto &label : compiled_labels )
{
std::printf( "> %s must be allocated at = 0x%p, encrypted rva = 0x%p\n", label.label_name.c_str(),
label.alloc_rva, label.enc_alloc_rva );
std::printf( "> " );
{
auto idx = 0u;
for ( auto byte : label.vinstrs )
std::printf( "0x%x ", byte );
std::printf( "\n" );
}
}
const auto cpp_result = gen_code( compiled_labels, argp.get< std::string >( "vmpbin" ), vmctx );
std::ofstream output( argp.get< std::string >( "out" ) );
output.write( cpp_result.data(), cpp_result.size() );
output.close();
std::printf( "> generated header file...\n" );
}