From b123113171a624639df771e9cf5c10eff3582e50 Mon Sep 17 00:00:00 2001 From: _xeroxz Date: Fri, 13 Aug 2021 21:40:46 -0700 Subject: [PATCH] added support for virtual jmp tables... TODO: make sure im serializing .vmp2 file format v4 correctly... --- dependencies/vmprofiler | 2 +- src/main.cpp | 60 +++++++++++++++++++++++++++---------- src/vmemu_t.cpp | 66 ++++++++++++++++++++++++++++++++++++++++- 3 files changed, 111 insertions(+), 17 deletions(-) diff --git a/dependencies/vmprofiler b/dependencies/vmprofiler index f06bf5f..fb59f8f 160000 --- a/dependencies/vmprofiler +++ b/dependencies/vmprofiler @@ -1 +1 @@ -Subproject commit f06bf5f6b72b1d52a6156d6828675c77ceaee7e2 +Subproject commit fb59f8f58f86a7abe461999315bfbd40bca9622c diff --git a/src/main.cpp b/src/main.cpp index e5d09f2..0252fb1 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -92,50 +92,80 @@ int __cdecl main( int argc, const char *argv[] ) 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 ], 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 ] ); + 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" ); - vmp2::v3::file_header file_header; + vmp2::v4::file_header file_header; file_header.magic = VMP_MAGIC; 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.image_base = image_base; file_header.vm_entry_rva = vm_entry_rva; file_header.module_offset = sizeof file_header; file_header.module_size = image_size; - file_header.code_block_offset = image_size + sizeof file_header; - file_header.code_block_count = code_blocks.size(); + file_header.rtn_count = 1; + file_header.rtn_offset = image_size + sizeof file_header; + vmp2::v4::rtn_t rtn{ code_blocks.size() }; 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 ); + output.write( reinterpret_cast< const char * >( &rtn ), sizeof vmp2::v4::rtn_t::code_block_count ); for ( const auto &code_block : code_blocks ) { - const auto _code_block_size = - ( code_block.vinstrs.size() * sizeof vm::instrs::virt_instr_t ) + sizeof vmp2::v3::code_block_t; + const auto _code_block_size = sizeof vmp2::v4::code_block_t + ( code_block.jcc.block_addr.size() * 8 ); - vmp2::v3::code_block_t *_code_block = - reinterpret_cast< vmp2::v3::code_block_t * >( malloc( _code_block_size ) ); + 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->jcc = code_block.jcc; _code_block->next_block_offset = _code_block_size; - _code_block->vinstr_count = code_block.vinstrs.size(); + _code_block->jcc.num_block_addrs = code_block.jcc.block_addr.size(); + + // serialize jcc data... + for ( auto idx = 0u; idx < code_block.jcc.block_addr.size(); ++idx ) + _code_block->jcc.block_addr[ idx ] = code_block.jcc.block_addr[ idx ]; + + output.write( reinterpret_cast< const char * >( _code_block ), + sizeof vmp2::v4::code_block_t + ( code_block.jcc.block_addr.size() * 8 ) ); + + // serialize virtual instructions... + auto vinstr_count = ( std::uint32_t )code_block.vinstrs.size(); + output.write( reinterpret_cast< const char * >( &vinstr_count ), sizeof vinstr_count ); for ( auto idx = 0u; idx < code_block.vinstrs.size(); ++idx ) - _code_block->vinstr[ idx ] = code_block.vinstrs[ idx ]; + { + const auto& vinstr = code_block.vinstrs[ idx ]; + output.write( reinterpret_cast< const char * >( &vinstr ), sizeof vinstr ); + } - output.write( reinterpret_cast< const char * >( _code_block ), _code_block_size ); + free( _code_block ); } - output.close(); } else if ( parser.exists( "unpack" ) && parser.exists( "out" ) ) diff --git a/src/vmemu_t.cpp b/src/vmemu_t.cpp index 5b18a7b..f17c388 100644 --- a/src/vmemu_t.cpp +++ b/src/vmemu_t.cpp @@ -209,6 +209,64 @@ namespace vm code_blocks.push_back( branch_block ); 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; 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 ); @@ -415,7 +480,6 @@ namespace vm } 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 ) {