Merge branch 'dev' into 'master'

added support for virtual jmp tables... (switch cases)

See merge request vmp2/vmemu!8
merge-requests/9/merge
_xeroxz 3 years ago
commit b15e9ba930

@ -1 +1 @@
Subproject commit f06bf5f6b72b1d52a6156d6828675c77ceaee7e2 Subproject commit 05c98b1ef57c3375ffd455221a3be1be6110d4eb

@ -13,6 +13,10 @@ int __cdecl main( int argc, const char *argv[] )
parser.add_argument().name( "--bin" ).description( "path to unpacked virtualized binary..." ); parser.add_argument().name( "--bin" ).description( "path to unpacked virtualized binary..." );
parser.add_argument().name( "--out" ).description( "output file name..." ); parser.add_argument().name( "--out" ).description( "output file name..." );
parser.add_argument().name( "--unpack" ).description( "unpack a vmp2 binary..." ); parser.add_argument().name( "--unpack" ).description( "unpack a vmp2 binary..." );
parser.add_argument()
.name( "--emuall" )
.description( "scan for all vm enters and trace all of them... this may take a few minutes..." );
parser.add_argument() parser.add_argument()
.name( "--locateconst" ) .name( "--locateconst" )
.description( "scan all vm enters for a specific constant value...\n" ); .description( "scan all vm enters for a specific constant value...\n" );
@ -92,50 +96,98 @@ int __cdecl main( int argc, const char *argv[] )
if ( code_block.jcc.has_jcc ) if ( code_block.jcc.has_jcc )
{ {
if ( code_block.jcc.type == vm::instrs::jcc_type::branching ) switch ( code_block.jcc.type )
{
case vm::instrs::jcc_type::branching:
{
std::printf( "> branch 1 = %p, branch 2 = %p\n", code_block.jcc.block_addr[ 0 ], std::printf( "> branch 1 = %p, branch 2 = %p\n", code_block.jcc.block_addr[ 0 ],
code_block.jcc.block_addr[ 1 ] ); code_block.jcc.block_addr[ 1 ] );
else break;
}
case vm::instrs::jcc_type::absolute:
{
std::printf( "> branch 1 = %p\n", code_block.jcc.block_addr[ 0 ] ); std::printf( "> branch 1 = %p\n", code_block.jcc.block_addr[ 0 ] );
break;
}
case vm::instrs::jcc_type::switch_case:
{
std::printf( "> switch case blocks:\n" );
for ( auto idx = 0u; idx < code_block.jcc.block_addr.size(); ++idx )
std::printf( " case block at = 0x%p\n", code_block.jcc.block_addr[ idx ] );
break;
}
}
} }
} }
std::printf( "> serializing results....\n" ); std::printf( "> serializing results....\n" );
vmp2::v3::file_header file_header; vmp2::v4::file_header file_header;
file_header.magic = VMP_MAGIC; file_header.magic = VMP_MAGIC;
file_header.epoch_time = std::time( nullptr ); file_header.epoch_time = std::time( nullptr );
file_header.version = vmp2::version_t::v3; file_header.version = vmp2::version_t::v4;
file_header.module_base = module_base; file_header.module_base = module_base;
file_header.image_base = image_base; file_header.image_base = image_base;
file_header.vm_entry_rva = vm_entry_rva; file_header.vm_entry_rva = vm_entry_rva;
file_header.module_offset = sizeof file_header; file_header.module_offset = sizeof file_header;
file_header.module_size = image_size; file_header.module_size = image_size;
file_header.code_block_offset = image_size + sizeof file_header; file_header.rtn_count = 1;
file_header.code_block_count = code_blocks.size(); file_header.rtn_offset = image_size + sizeof file_header;
vmp2::v4::rtn_t rtn;
std::ofstream output( parser.get< std::string >( "out" ), std::ios::binary ); std::ofstream output( parser.get< std::string >( "out" ), std::ios::binary );
output.write( reinterpret_cast< const char * >( &file_header ), sizeof file_header ); output.write( reinterpret_cast< const char * >( &file_header ), sizeof file_header );
output.write( reinterpret_cast< const char * >( module_base ), image_size ); output.write( reinterpret_cast< const char * >( module_base ), image_size );
std::vector< vmp2::v4::code_block_t * > vmp2_blocks;
for ( const auto &code_block : code_blocks ) for ( const auto &code_block : code_blocks )
{ {
const auto _code_block_size = const auto _code_block_size = sizeof vmp2::v4::code_block_t + ( code_block.jcc.block_addr.size() * 8 ) +
( code_block.vinstrs.size() * sizeof vm::instrs::virt_instr_t ) + sizeof vmp2::v3::code_block_t; code_block.vinstrs.size() * sizeof vm::instrs::virt_instr_t;
vmp2::v3::code_block_t *_code_block = vmp2::v4::code_block_t *_code_block =
reinterpret_cast< vmp2::v3::code_block_t * >( malloc( _code_block_size ) ); reinterpret_cast< vmp2::v4::code_block_t * >( malloc( _code_block_size ) );
// serialize block meta data...
_code_block->vip_begin = code_block.vip_begin; _code_block->vip_begin = code_block.vip_begin;
_code_block->jcc = code_block.jcc;
_code_block->next_block_offset = _code_block_size; _code_block->next_block_offset = _code_block_size;
_code_block->vinstr_count = code_block.vinstrs.size(); _code_block->vinstr_count = code_block.vinstrs.size();
_code_block->has_jcc = code_block.jcc.has_jcc;
_code_block->jcc_type = code_block.jcc.type;
_code_block->num_block_addrs = code_block.jcc.block_addr.size();
// serialize jcc branches...
for ( auto idx = 0u; idx < code_block.jcc.block_addr.size(); ++idx )
_code_block->branch_addr[ idx ] = code_block.jcc.block_addr[ idx ];
auto block_vinstrs = reinterpret_cast< vm::instrs::virt_instr_t * >(
reinterpret_cast< std::uintptr_t >( _code_block ) + sizeof vmp2::v4::code_block_t +
( code_block.jcc.block_addr.size() * 8 ) );
for ( auto idx = 0u; idx < code_block.vinstrs.size(); ++idx ) for ( auto idx = 0u; idx < code_block.vinstrs.size(); ++idx )
_code_block->vinstr[ idx ] = code_block.vinstrs[ idx ]; block_vinstrs[ idx ] = code_block.vinstrs[ idx ];
output.write( reinterpret_cast< const char * >( _code_block ), _code_block_size ); vmp2_blocks.push_back( _code_block );
} }
std::size_t code_blocks_size = sizeof( vmp2::v4::rtn_t::size ) + sizeof( vmp2::v4::rtn_t::code_block_count ) +
sizeof( vmp2::v4::rtn_t::vm_enter_offset );
std::for_each( vmp2_blocks.begin(), vmp2_blocks.end(), [ & ]( vmp2::v4::code_block_t *vmp2_block ) -> void {
code_blocks_size += vmp2_block->next_block_offset;
} );
rtn.size = code_blocks_size;
rtn.code_block_count = vmp2_blocks.size();
rtn.vm_enter_offset = vm_entry_rva;
output.write( reinterpret_cast< const char * >( &rtn ), sizeof( vmp2::v4::rtn_t::size ) +
sizeof( vmp2::v4::rtn_t::code_block_count ) +
sizeof( vmp2::v4::rtn_t::vm_enter_offset ) );
std::for_each( vmp2_blocks.begin(), vmp2_blocks.end(), [ & ]( vmp2::v4::code_block_t *vmp2_block ) -> void {
output.write( reinterpret_cast< const char * >( vmp2_block ), vmp2_block->next_block_offset );
free( vmp2_block );
} );
output.close(); output.close();
} }
else if ( parser.exists( "unpack" ) && parser.exists( "out" ) ) else if ( parser.exists( "unpack" ) && parser.exists( "out" ) )
@ -166,28 +218,141 @@ int __cdecl main( int argc, const char *argv[] )
output.write( reinterpret_cast< char * >( unpacked_bin.data() ), unpacked_bin.size() ); output.write( reinterpret_cast< char * >( unpacked_bin.data() ), unpacked_bin.size() );
output.close(); output.close();
} }
else if ( parser.exists( "bin" ) && parser.exists( "locateconst" ) ) else if ( parser.exists( "bin" ) && parser.exists( "emuall" ) && parser.exists( "out" ) )
{ {
const auto module_base = reinterpret_cast< std::uintptr_t >( const auto module_base = reinterpret_cast< std::uintptr_t >(
LoadLibraryExA( parser.get< std::string >( "bin" ).c_str(), NULL, DONT_RESOLVE_DLL_REFERENCES ) ); LoadLibraryExA( parser.get< std::string >( "bin" ).c_str(), NULL, DONT_RESOLVE_DLL_REFERENCES ) );
const auto const_val = std::strtoull( parser.get< std::string >( "locateconst" ).c_str(), nullptr, 16 );
const auto image_base = umtils->image_base( parser.get< std::string >( "bin" ).c_str() ); const auto image_base = umtils->image_base( parser.get< std::string >( "bin" ).c_str() );
const auto image_size = NT_HEADER( module_base )->OptionalHeader.SizeOfImage; const auto image_size = NT_HEADER( module_base )->OptionalHeader.SizeOfImage;
auto vm_handler_tables = vm::locate::all_handler_tables( module_base ); auto vm_handler_tables = vm::locate::all_handler_tables( module_base );
auto vm_enters = vm::locate::all_vm_enters( module_base, vm_handler_tables ); auto vm_enters = vm::locate::all_vm_enters( module_base, vm_handler_tables );
std::printf( "> number of vm enters = %d\n", vm_enters.size() ); std::vector< std::pair< std::uintptr_t, std::vector< vm::instrs::code_block_t > > > virt_rtns;
if ( std::find_if( vm_enters.begin() + 1, vm_enters.end(), for ( const auto &[ vm_enter_offset, encrypted_rva ] : vm_enters )
[ & ]( const std::pair< std::uint32_t, std::uint32_t > &vm_enter_data ) -> bool {
return vm_enter_data.second == vm_enters[ 0 ].second;
} ) != vm_enters.end() )
{ {
std::printf( "> optimizations can be done.\n" ); std::printf( "> emulating vm enter at rva = 0x%x\n", vm_enter_offset );
std::getchar(); vm::ctx_t vm_ctx( module_base, image_base, image_size, vm_enter_offset );
if ( !vm_ctx.init() )
{
std::printf( "[!] failed to init vmctx... this can be for many reasons..."
" try validating your vm entry rva... make sure the binary is unpacked and is"
"protected with VMProtect 2...\n" );
return -1;
}
vm::emu_t emu( &vm_ctx );
if ( !emu.init() )
{
std::printf( "[!] failed to init emulator...\n" );
return -1;
}
std::vector< vm::instrs::code_block_t > code_blocks;
if ( !emu.get_trace( code_blocks ) )
{
std::printf( "[!] something failed during tracing, review the console for more information...\n" );
continue;
}
std::printf( "> number of blocks = %d\n", code_blocks.size() );
virt_rtns.push_back( { vm_enter_offset, code_blocks } );
} }
std::printf( "> traced %d virtual routines...\n", virt_rtns.size() );
std::printf( "> serializing results....\n" );
vmp2::v4::file_header file_header;
file_header.magic = VMP_MAGIC;
file_header.epoch_time = std::time( nullptr );
file_header.version = vmp2::version_t::v4;
file_header.module_base = module_base;
file_header.image_base = image_base;
file_header.vm_entry_rva = 0ull;
file_header.module_offset = sizeof file_header;
file_header.module_size = image_size;
file_header.rtn_count = virt_rtns.size();
file_header.rtn_offset = image_size + sizeof file_header;
std::ofstream output( parser.get< std::string >( "out" ), std::ios::binary );
output.write( reinterpret_cast< const char * >( &file_header ), sizeof file_header );
output.write( reinterpret_cast< const char * >( module_base ), image_size );
for ( auto [ vm_enter_offset, virt_rtn ] : virt_rtns )
{
vmp2::v4::rtn_t rtn{ virt_rtn.size() };
std::vector< vmp2::v4::code_block_t * > vmp2_blocks;
for ( const auto &code_block : virt_rtn )
{
const auto _code_block_size = sizeof vmp2::v4::code_block_t + ( code_block.jcc.block_addr.size() * 8 ) +
code_block.vinstrs.size() * sizeof vm::instrs::virt_instr_t;
vmp2::v4::code_block_t *_code_block =
reinterpret_cast< vmp2::v4::code_block_t * >( malloc( _code_block_size ) );
// serialize block meta data...
_code_block->vip_begin = code_block.vip_begin;
_code_block->next_block_offset = _code_block_size;
_code_block->vinstr_count = code_block.vinstrs.size();
_code_block->has_jcc = code_block.jcc.has_jcc;
_code_block->jcc_type = code_block.jcc.type;
_code_block->num_block_addrs = code_block.jcc.block_addr.size();
// serialize jcc branches...
for ( auto idx = 0u; idx < code_block.jcc.block_addr.size(); ++idx )
_code_block->branch_addr[ idx ] = code_block.jcc.block_addr[ idx ];
auto block_vinstrs = reinterpret_cast< vm::instrs::virt_instr_t * >(
reinterpret_cast< std::uintptr_t >( _code_block ) + sizeof vmp2::v4::code_block_t +
( code_block.jcc.block_addr.size() * 8 ) );
for ( auto idx = 0u; idx < code_block.vinstrs.size(); ++idx )
block_vinstrs[ idx ] = code_block.vinstrs[ idx ];
vmp2_blocks.push_back( _code_block );
}
std::size_t code_blocks_size = sizeof( vmp2::v4::rtn_t::size ) +
sizeof( vmp2::v4::rtn_t::vm_enter_offset ) +
sizeof( vmp2::v4::rtn_t::code_block_count );
std::for_each( vmp2_blocks.begin(), vmp2_blocks.end(), [ & ]( vmp2::v4::code_block_t *vmp2_block ) -> void {
code_blocks_size += vmp2_block->next_block_offset;
} );
rtn.size = code_blocks_size;
rtn.code_block_count = vmp2_blocks.size();
rtn.vm_enter_offset = vm_enter_offset;
output.write( reinterpret_cast< const char * >( &rtn ), sizeof( vmp2::v4::rtn_t::size ) +
sizeof( vmp2::v4::rtn_t::code_block_count ) +
sizeof( vmp2::v4::rtn_t::vm_enter_offset ) );
std::for_each( vmp2_blocks.begin(), vmp2_blocks.end(), [ & ]( vmp2::v4::code_block_t *vmp2_block ) -> void {
output.write( reinterpret_cast< const char * >( vmp2_block ), vmp2_block->next_block_offset );
free( vmp2_block );
} );
}
output.close();
}
else if ( parser.exists( "bin" ) && parser.exists( "locateconst" ) )
{
const auto module_base = reinterpret_cast< std::uintptr_t >(
LoadLibraryExA( parser.get< std::string >( "bin" ).c_str(), NULL, DONT_RESOLVE_DLL_REFERENCES ) );
const auto const_val = std::strtoull( parser.get< std::string >( "locateconst" ).c_str(), nullptr, 16 );
const auto image_base = umtils->image_base( parser.get< std::string >( "bin" ).c_str() );
const auto image_size = NT_HEADER( module_base )->OptionalHeader.SizeOfImage;
auto vm_handler_tables = vm::locate::all_handler_tables( module_base );
auto vm_enters = vm::locate::all_vm_enters( module_base, vm_handler_tables );
std::printf( "> number of vm enters = %d\n", vm_enters.size() );
for ( const auto &[ vm_enter_offset, encrypted_rva ] : vm_enters ) for ( const auto &[ vm_enter_offset, encrypted_rva ] : vm_enters )
{ {
std::printf( "> emulating vm enter at rva = 0x%x\n", vm_enter_offset ); std::printf( "> emulating vm enter at rva = 0x%x\n", vm_enter_offset );

@ -209,6 +209,64 @@ namespace vm
code_blocks.push_back( branch_block ); code_blocks.push_back( branch_block );
break; break;
} }
case vm::instrs::jcc_type::switch_case:
{
for ( auto _idx = 0u; _idx < _code_block.code_block.jcc.block_addr.size(); ++_idx )
{
if ( std::find( vip_begins.begin(), vip_begins.end(),
_code_block.code_block.jcc.block_addr[ _idx ] ) != vip_begins.end() )
continue;
std::uintptr_t rbp = 0ull;
std::uint32_t branch_rva =
( _code_block.code_block.jcc.block_addr[ _idx ] - g_vm_ctx->module_base ) +
g_vm_ctx->image_base;
// setup object globals so that the tracing will work...
code_block_data_t branch_block{ {}, nullptr, nullptr };
cc_block = &branch_block;
g_vm_ctx = _code_block.g_vm_ctx.get();
// restore register values...
if ( ( err = uc_context_restore( uc_ctx, _code_block.cpu_ctx->context ) ) )
{
std::printf( "> failed to restore emu context... reason = %d\n", err );
return false;
}
// restore stack values...
if ( ( err = uc_mem_write( uc_ctx, STACK_BASE, _code_block.cpu_ctx->stack, STACK_SIZE ) ) )
{
std::printf( "> failed to restore stack... reason = %d\n", err );
return false;
}
// get the address in rbp (top of vsp)... then patch the branch rva...
if ( ( err = uc_reg_read( uc_ctx, UC_X86_REG_RBP, &rbp ) ) )
{
std::printf( "> failed to read rbp... reason = %d\n", err );
return false;
}
// patch the branch rva...
if ( ( err = uc_mem_write( uc_ctx, rbp, &branch_rva, sizeof branch_rva ) ) )
{
std::printf( "> failed to patch branch rva... reason = %d\n", err );
return false;
}
std::printf( "> beginning execution at = 0x%p\n", _code_block.cpu_ctx->rip );
if ( ( err = uc_emu_start( uc_ctx, _code_block.cpu_ctx->rip, 0ull, 0ull, 0ull ) ) )
{
std::printf( "> error starting emu... reason = %d\n", err );
return false;
}
// push back new block that has been traced...
code_blocks.push_back( branch_block );
}
break;
}
} }
} }
@ -231,6 +289,13 @@ namespace vm
( code_block.jcc.block_addr[ 0 ] - g_vm_ctx->module_base ) + g_vm_ctx->image_base; ( code_block.jcc.block_addr[ 0 ] - g_vm_ctx->module_base ) + g_vm_ctx->image_base;
break; break;
} }
case vm::instrs::jcc_type::switch_case:
{
for ( auto idx = 0u; idx < code_block.jcc.block_addr.size(); ++idx )
code_block.jcc.block_addr[ idx ] =
( code_block.jcc.block_addr[ idx ] - g_vm_ctx->module_base ) + g_vm_ctx->image_base;
break;
}
} }
} }
entries.push_back( code_block ); entries.push_back( code_block );
@ -415,7 +480,6 @@ namespace vm
} }
obj->cc_block->code_block.vinstrs.push_back( vinstr.value() ); obj->cc_block->code_block.vinstrs.push_back( vinstr.value() );
std::printf( "> %s %p\n", vm_handler.profile ? vm_handler.profile->name : "UNK", vm_handler_addr );
if ( vm_handler.profile ) if ( vm_handler.profile )
{ {

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