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Merge branch 'linux-port' into 'master'

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porting project to support linux...

See merge request vmp2/vmemu!14
merge-requests/15/merge
_xeroxz 3 years ago
parent 1385a7cfe2 c798e736d2
commit e0d756c252
6 changed files with 1712 additions and 1560 deletions
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2
dependencies/vmprofiler vendored

@ -1 +1 @@
Subproject commit 1b6875d18825529907289bc87990fed5d99e7f96 Subproject commit dd7d3777ad10373d0eeb23c118e4bdcfc7464494

101
include/unpacker.hpp
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@ -1,15 +1,16 @@
#pragma once #pragma once
#include <functional> #include <Zydis/Zydis.h>
#include <unicorn/unicorn.h> #include <unicorn/unicorn.h>
#include <Zydis/Zydis.h>
#include <atomic> #include <atomic>
#include <fstream> #include <fstream>
#include <functional>
#include <map> #include <map>
#include <nt/image.hpp> #include <nt/image.hpp>
#include <vector> #include <vector>
#include <xtils.hpp> #include <vmprofiler.hpp>
#define PACKED_FILE_HANDLE 0x69420
#define PAGE_4KB 0x1000 #define PAGE_4KB 0x1000
#define STACK_SIZE PAGE_4KB * 512 #define STACK_SIZE PAGE_4KB * 512
@ -23,50 +24,82 @@
#define LOCAL_FREE_VECTOR 3 #define LOCAL_FREE_VECTOR 3
#define LOAD_LIBRARY_VECTOR 4 #define LOAD_LIBRARY_VECTOR 4
#define NT_QUERY_SYSTEM_INFO_VECTOR 5 #define NT_QUERY_SYSTEM_INFO_VECTOR 5
#define GET_MODULE_FILE_NAME_W_VECTOR 6
#define CREATE_FILE_W_VECTOR 7
#define GET_FILE_SIZE_VECTOR 8
#define CREATE_FILE_MAPPING_VECTOR 9
#define MAP_VIEW_OF_FILE_VECTOR 10
#define UNMAP_VIEW_OF_FILE_VECTOR 11
#define CLOSE_HANDLE_VECTOR 12
#define VIRTUAL_PROTECT_VECTOR 13
#define MOV_RAX_0_SIG "\x48\xB8\x00\x00\x00\x00\x00\x00\x00\x00" #define MOV_RAX_0_SIG "\x48\xB8\x00\x00\x00\x00\x00\x00\x00\x00"
#define MOV_RAX_0_MASK "xxxxxxxxxx" #define MOV_RAX_0_MASK "xxxxxxxxxx"
static_assert( sizeof MOV_RAX_0_SIG == sizeof MOV_RAX_0_MASK, "signature and mask sizes are wrong..." ); static_assert(sizeof MOV_RAX_0_SIG == sizeof MOV_RAX_0_MASK,
"signature and mask sizes are wrong...");
namespace engine namespace engine {
{ class unpack_t {
class unpack_t
{
public: public:
explicit unpack_t( const std::vector< std::uint8_t > &bin ); explicit unpack_t(const std::string &module_name,
~unpack_t( void ); const std::vector<std::uint8_t> &bin);
~unpack_t(void);
bool init( void ); bool init(void);
bool unpack( std::vector< std::uint8_t > &output ); bool unpack(std::vector<std::uint8_t> &output);
private: private:
using iat_hook_t = std::function< void( uc_engine *, unpack_t * ) >; using iat_hook_t = std::function<void(uc_engine *, unpack_t *)>;
uc_engine *uc_ctx; uc_engine *uc_ctx;
std::vector< uint8_t > bin, map_bin; std::vector<uint8_t> bin, map_bin;
std::vector< uc_hook * > uc_hooks; std::vector<uc_hook *> uc_hooks;
std::string module_name;
std::uintptr_t img_base, img_size, heap_offset, pack_section_offset; std::uintptr_t img_base, img_size, heap_offset, pack_section_offset;
win::image_t<> *win_img; win::image_t<> *win_img;
static void local_alloc_hook( uc_engine *, unpack_t * ); static void local_alloc_hook(uc_engine *, unpack_t *);
static void local_free_hook( uc_engine *, unpack_t * ); static void local_free_hook(uc_engine *, unpack_t *);
static void load_library_hook( uc_engine *, unpack_t * ); static void load_library_hook(uc_engine *, unpack_t *);
static void uc_strcpy( uc_engine *, char *buff, std::uintptr_t addr ); static void get_module_file_name_w_hook(uc_engine *, unpack_t *);
static void create_file_w_hook(uc_engine *, unpack_t *);
static bool iat_dispatcher( uc_engine *uc, uint64_t address, uint32_t size, unpack_t *unpack ); static void get_file_size_hook(uc_engine *, unpack_t *);
static bool unpack_section_callback( uc_engine *uc, uc_mem_type type, uint64_t address, int size, int64_t value, static void create_file_mapping_hook(uc_engine *, unpack_t *);
unpack_t *unpack ); static void map_view_of_file_hook(uc_engine *, unpack_t *);
static void unmap_view_of_file_hook(uc_engine *, unpack_t *);
static bool code_exec_callback( uc_engine *uc, uint64_t address, uint32_t size, unpack_t *unpack ); static void close_handle_hook(uc_engine *, unpack_t *);
static void invalid_mem( uc_engine *uc, uc_mem_type type, uint64_t address, int size, int64_t value, static void virtual_protect_hook(uc_engine *, unpack_t *);
unpack_t *unpack );
static void uc_strcpy(uc_engine *uc, char *buff, std::uintptr_t addr);
std::vector< std::uintptr_t > loaded_modules; static void uc_strcpy(uc_engine *uc, std::uintptr_t addr, char *buff);
std::map< std::string, std::pair< std::uint32_t, iat_hook_t > > iat_hooks = {
{ "LocalAlloc", { LOCAL_ALLOC_VECTOR, &local_alloc_hook } }, static bool iat_dispatcher(uc_engine *uc, uint64_t address, uint32_t size,
{ "LocalFree", { LOCAL_FREE_VECTOR, &local_free_hook } }, unpack_t *unpack);
{ "LoadLibraryA", { LOAD_LIBRARY_VECTOR, &load_library_hook } } };
}; static bool unpack_section_callback(uc_engine *uc, uc_mem_type type,
uint64_t address, int size, int64_t value,
unpack_t *unpack);
static void invalid_mem(uc_engine *uc, uc_mem_type type, uint64_t address,
int size, int64_t value, unpack_t *unpack);
std::map<std::string, std::uintptr_t> loaded_modules;
std::map<std::string, std::pair<std::uint32_t, iat_hook_t> > iat_hooks = {
{"LocalAlloc", {LOCAL_ALLOC_VECTOR, &local_alloc_hook}},
{"LocalFree", {LOCAL_FREE_VECTOR, &local_free_hook}},
{"LoadLibraryA", {LOAD_LIBRARY_VECTOR, &load_library_hook}},
{"GetModuleFileNameW",
{GET_MODULE_FILE_NAME_W_VECTOR, &get_module_file_name_w_hook}},
{"CreateFileW", {CREATE_FILE_W_VECTOR, &create_file_w_hook}},
{"GetFileSize", {GET_FILE_SIZE_VECTOR, &get_file_size_hook}},
{"CreateFileMappingW",
{CREATE_FILE_MAPPING_VECTOR, &create_file_mapping_hook}},
{"MapViewOfFile", {MAP_VIEW_OF_FILE_VECTOR, &map_view_of_file_hook}},
{"UnmapViewOfFile",
{UNMAP_VIEW_OF_FILE_VECTOR, &unmap_view_of_file_hook}},
{"CloseHandle", {CLOSE_HANDLE_VECTOR, &close_handle_hook}},
{"VirtualProtect", {VIRTUAL_PROTECT_VECTOR, &virtual_protect_hook}}};
};
} // namespace engine } // namespace engine

46
include/vmemu_t.hpp
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@ -1,6 +1,7 @@
#pragma once #pragma once
#include <unicorn/unicorn.h> #include <unicorn/unicorn.h>
#include <atomic>
#include <nt/image.hpp> #include <nt/image.hpp>
#include <vmprofiler.hpp> #include <vmprofiler.hpp>
@ -10,32 +11,28 @@
#define STACK_BASE 0xFFFF000000000000 #define STACK_BASE 0xFFFF000000000000
#define IAT_VECTOR_TABLE 0xFFFFF00000000000 #define IAT_VECTOR_TABLE 0xFFFFF00000000000
namespace vm namespace vm {
{ inline bool g_force_emu = false;
inline bool g_force_emu = false;
class emu_t class emu_t {
{ struct cpu_ctx_t {
struct cpu_ctx_t
{
std::uintptr_t rip; std::uintptr_t rip;
uc_context *context; uc_context *context;
std::uint8_t stack[ STACK_SIZE ]; std::uint8_t stack[STACK_SIZE];
}; };
struct code_block_data_t struct code_block_data_t {
{
vm::instrs::code_block_t code_block; vm::instrs::code_block_t code_block;
std::shared_ptr< cpu_ctx_t > cpu_ctx; std::shared_ptr<cpu_ctx_t> cpu_ctx;
std::shared_ptr< vm::ctx_t > g_vm_ctx; std::shared_ptr<vm::ctx_t> g_vm_ctx;
}; };
public: public:
explicit emu_t( vm::ctx_t *vm_ctx ); explicit emu_t(vm::ctx_t *vm_ctx);
~emu_t(); ~emu_t();
bool init(); bool init();
bool get_trace( std::vector< vm::instrs::code_block_t > &code_blocks ); bool get_trace(std::vector<vm::instrs::code_block_t> &code_blocks);
private: private:
std::uintptr_t img_base, img_size; std::uintptr_t img_base, img_size;
@ -45,14 +42,15 @@ namespace vm
vm::ctx_t *g_vm_ctx; vm::ctx_t *g_vm_ctx;
code_block_data_t *cc_block; code_block_data_t *cc_block;
std::vector< std::uintptr_t > vip_begins; std::vector<std::uintptr_t> vip_begins;
std::vector< code_block_data_t > code_blocks; std::vector<code_block_data_t> code_blocks;
std::map< std::uintptr_t, std::shared_ptr< vm::ctx_t > > vm_ctxs; std::map<std::uintptr_t, std::shared_ptr<vm::ctx_t> > vm_ctxs;
uc_err create_entry( vmp2::v2::entry_t *entry ); uc_err create_entry(vmp2::v2::entry_t *entry);
static void int_callback( uc_engine *uc, std::uint32_t intno, emu_t *obj ); static void int_callback(uc_engine *uc, std::uint32_t intno, emu_t *obj);
static bool code_exec_callback( uc_engine *uc, uint64_t address, uint32_t size, emu_t *obj ); static bool code_exec_callback(uc_engine *uc, uint64_t address, uint32_t size,
static void invalid_mem( uc_engine *uc, uc_mem_type type, uint64_t address, int size, int64_t value, emu_t *obj);
emu_t *obj ); static void invalid_mem(uc_engine *uc, uc_mem_type type, uint64_t address,
}; int size, int64_t value, emu_t *obj);
};
} // namespace vm } // namespace vm

509
src/main.cpp
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@ -1,131 +1,183 @@
#include "unpacker.hpp"
#include "vmemu_t.hpp"
#include <cli-parser.hpp> #include <cli-parser.hpp>
#include <fstream> #include <fstream>
#include <iostream> #include <iostream>
#include <xtils.hpp>
int __cdecl main( int argc, const char *argv[] )
{
argparse::argument_parser_t parser( "VMEmu", "VMProtect 2 VM Handler Emulator" );
parser.add_argument().name( "--vmentry" ).description( "relative virtual address to a vm entry..." );
parser.add_argument().name( "--bin" ).description( "path to unpacked virtualized binary..." );
parser.add_argument().name( "--out" ).description( "output file name..." );
parser.add_argument().name( "--unpack" ).description( "unpack a vmp2 binary..." );
parser.add_argument().names( { "-f", "--force" } ).description( "force emulation of unknown vm handlers...\n" );
parser.add_argument()
.name( "--emuall" )
.description( "scan for all vm enters and trace all of them... this may take a few minutes..." );
#include "unpacker.hpp"
#include "vmemu_t.hpp"
int __cdecl main(int argc, const char *argv[]) {
argparse::argument_parser_t parser("VMEmu",
"VMProtect 2 VM Handler Emulator");
parser.add_argument() parser.add_argument()
.name( "--locateconst" ) .name("--vmentry")
.description( "scan all vm enters for a specific constant value...\n" ); .description("relative virtual address to a vm entry...");
parser.add_argument()
.name("--bin")
.description("path to unpacked virtualized binary...")
.required(true);
parser.add_argument()
.name("--out")
.description("output file name...")
.required(true);
parser.add_argument().name("--unpack").description("unpack a vmp2 binary...");
parser.add_argument()
.names({"-f", "--force"})
.description("force emulation of unknown vm handlers...");
parser.add_argument()
.name("--emuall")
.description(
"scan for all vm enters and trace all of them... this may take a few "
"minutes...");
parser.enable_help(); parser.enable_help();
auto result = parser.parse( argc, argv ); auto result = parser.parse(argc, argv);
if ( result ) if (result) {
{ std::printf("[!] error parsing commandline arguments... reason = %s\n",
std::printf( "[!] error parsing commandline arguments... reason = %s\n", result.what().c_str() ); result.what().c_str());
return -1; return -1;
} }
if ( parser.exists( "help" ) ) if (parser.exists("help")) {
{
parser.print_help(); parser.print_help();
return 0; return 0;
} }
auto umtils = xtils::um_t::get_instance(); vm::util::init();
vm::g_force_emu = parser.exists( "force" ); vm::g_force_emu = parser.exists("force");
if ( !parser.exists( "unpack" ) && parser.exists( "vmentry" ) && parser.exists( "bin" ) && parser.exists( "out" ) ) std::vector<std::uint8_t> module_data, tmp, unpacked_bin;
{ if (!vm::util::open_binary_file(parser.get<std::string>("bin"),
const auto module_base = reinterpret_cast< std::uintptr_t >( module_data)) {
LoadLibraryExA( parser.get< std::string >( "bin" ).c_str(), NULL, DONT_RESOLVE_DLL_REFERENCES ) ); std::printf("[!] failed to open binary file...\n");
if ( !module_base )
{
std::printf( "[!] failed to open binary file...\n" );
return -1; return -1;
} }
const auto vm_entry_rva = std::strtoull( parser.get< std::string >( "vmentry" ).c_str(), nullptr, 16 ); auto img = reinterpret_cast<win::image_t<> *>(module_data.data());
const auto image_base = umtils->image_base( parser.get< std::string >( "bin" ).c_str() ); auto image_size = img->get_nt_headers()->optional_header.size_image;
const auto image_size = NT_HEADER( module_base )->OptionalHeader.SizeOfImage; const auto image_base = img->get_nt_headers()->optional_header.image_base;
// page align the vector allocation so that unicorn-engine is happy girl...
tmp.resize(image_size + PAGE_4KB);
const std::uintptr_t module_base =
reinterpret_cast<std::uintptr_t>(tmp.data()) +
(PAGE_4KB - (reinterpret_cast<std::uintptr_t>(tmp.data()) & 0xFFFull));
std::memcpy((void *)module_base, module_data.data(), 0x1000);
std::for_each(img->get_nt_headers()->get_sections(),
img->get_nt_headers()->get_sections() +
img->get_nt_headers()->file_header.num_sections,
[&](const auto &section_header) {
std::memcpy(
(void *)(module_base + section_header.virtual_address),
module_data.data() + section_header.ptr_raw_data,
section_header.size_raw_data);
});
auto win_img = reinterpret_cast<win::image_t<> *>(module_base);
auto basereloc_dir =
win_img->get_directory(win::directory_id::directory_entry_basereloc);
auto reloc_dir = reinterpret_cast<win::reloc_directory_t *>(
basereloc_dir->rva + module_base);
win::reloc_block_t *reloc_block = &reloc_dir->first_block;
// apply relocations to all sections...
while (reloc_block->base_rva && reloc_block->size_block) {
std::for_each(reloc_block->begin(), reloc_block->end(),
[&](win::reloc_entry_t &entry) {
switch (entry.type) {
case win::reloc_type_id::rel_based_dir64: {
auto reloc_at = reinterpret_cast<std::uintptr_t *>(
entry.offset + reloc_block->base_rva + module_base);
*reloc_at = module_base + ((*reloc_at) - image_base);
break;
}
default:
break;
}
});
reloc_block = reloc_block->next();
}
std::printf( "> image base = %p, image size = %p, module base = %p\n", image_base, image_size, module_base ); std::printf("> image base = %p, image size = %p, module base = %p\n",
image_base, image_size, module_base);
if ( !image_base || !image_size || !module_base ) if (!image_base || !image_size || !module_base) {
{ std::printf("[!] failed to open binary on disk...\n");
std::printf( "[!] failed to open binary on disk...\n" );
return -1; return -1;
} }
std::vector< vm::instrs::code_block_t > code_blocks; if (parser.exists("vmentry")) {
vm::ctx_t vmctx( module_base, image_base, image_size, vm_entry_rva ); const auto vm_entry_rva =
std::strtoull(parser.get<std::string>("vmentry").c_str(), nullptr, 16);
std::vector<vm::instrs::code_block_t> code_blocks;
vm::ctx_t vmctx(module_base, image_base, image_size, vm_entry_rva);
if ( !vmctx.init() ) if (!vmctx.init()) {
{ std::printf(
std::printf( "[!] failed to init vmctx... this can be for many reasons..." "[!] failed to init vmctx... this can be for many reasons..."
" try validating your vm entry rva... make sure the binary is unpacked and is" " try validating your vm entry rva... make sure the binary is "
"protected with VMProtect 2...\n" ); "unpacked and is"
"protected with VMProtect 2...\n");
return -1; return -1;
} }
vm::emu_t emu( &vmctx ); vm::emu_t emu(&vmctx);
if ( !emu.init() ) if (!emu.init()) {
{ std::printf("[!] failed to init emulator...\n");
std::printf( "[!] failed to init emulator...\n" );
return -1; return -1;
} }
if ( !emu.get_trace( code_blocks ) ) if (!emu.get_trace(code_blocks)) {
{ std::printf(
std::printf( "[!] something failed during tracing, review the console for more information...\n" ); "[!] something failed during tracing, review the console for more "
"information...\n");
return -1; return -1;
} }
std::printf( "> number of blocks = %d\n", code_blocks.size() ); std::printf("> number of blocks = %d\n", code_blocks.size());
for ( auto &code_block : code_blocks ) for (auto &code_block : code_blocks) {
{ std::printf("> code block starts at = %p\n", code_block.vip_begin);
std::printf( "> code block starts at = %p\n", code_block.vip_begin ); std::printf("> number of virtual instructions = %d\n",
std::printf( "> number of virtual instructions = %d\n", code_block.vinstrs.size() ); code_block.vinstrs.size());
std::printf( "> does this code block have a jcc? %s\n", code_block.jcc.has_jcc ? "yes" : "no" ); std::printf("> does this code block have a jcc? %s\n",
code_block.jcc.has_jcc ? "yes" : "no");
if ( code_block.jcc.has_jcc )
{ if (code_block.jcc.has_jcc) {
switch ( code_block.jcc.type ) switch (code_block.jcc.type) {
{ case vm::instrs::jcc_type::branching: {
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 ] );
break; break;
} }
case vm::instrs::jcc_type::absolute: 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; break;
} }
case vm::instrs::jcc_type::switch_case: case vm::instrs::jcc_type::switch_case: {
{ std::printf("> switch case blocks:\n");
std::printf( "> switch case blocks:\n" ); for (auto idx = 0u; idx < code_block.jcc.block_addr.size(); ++idx)
for ( auto idx = 0u; idx < code_block.jcc.block_addr.size(); ++idx ) std::printf(" case block at = 0x%p\n",
std::printf( " case block at = 0x%p\n", code_block.jcc.block_addr[ idx ] ); code_block.jcc.block_addr[idx]);
break; break;
} }
} }
} }
} }
std::printf( "> serializing results....\n" ); std::printf("> serializing results....\n");
vmp2::v4::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::v4; 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;
@ -136,18 +188,20 @@ int __cdecl main( int argc, const char *argv[] )
file_header.rtn_offset = image_size + sizeof file_header; file_header.rtn_offset = image_size + sizeof file_header;
vmp2::v4::rtn_t rtn; 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),
output.write( reinterpret_cast< const char * >( module_base ), image_size ); sizeof file_header);
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 ) std::vector<vmp2::v4::code_block_t *> vmp2_blocks;
{ for (const auto &code_block : code_blocks) {
const auto _code_block_size = sizeof vmp2::v4::code_block_t + ( code_block.jcc.block_addr.size() * 8 ) + const auto _code_block_size =
code_block.vinstrs.size() * sizeof vm::instrs::virt_instr_t; 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 = vmp2::v4::code_block_t *_code_block =
reinterpret_cast< vmp2::v4::code_block_t * >( malloc( _code_block_size ) ); reinterpret_cast<vmp2::v4::code_block_t *>(malloc(_code_block_size));
// serialize block meta data... // serialize block meta data...
_code_block->vip_begin = code_block.vip_begin; _code_block->vip_begin = code_block.vip_begin;
@ -158,119 +212,112 @@ int __cdecl main( int argc, const char *argv[] )
_code_block->num_block_addrs = code_block.jcc.block_addr.size(); _code_block->num_block_addrs = code_block.jcc.block_addr.size();
// serialize jcc branches... // serialize jcc branches...
for ( auto idx = 0u; idx < code_block.jcc.block_addr.size(); ++idx ) for (auto idx = 0u; idx < code_block.jcc.block_addr.size(); ++idx)
_code_block->branch_addr[ idx ] = code_block.jcc.block_addr[ idx ]; _code_block->branch_addr[idx] = code_block.jcc.block_addr[idx];
auto block_vinstrs = reinterpret_cast< vm::instrs::virt_instr_t * >( auto block_vinstrs = reinterpret_cast<vm::instrs::virt_instr_t *>(
reinterpret_cast< std::uintptr_t >( _code_block ) + sizeof vmp2::v4::code_block_t + reinterpret_cast<std::uintptr_t>(_code_block) +
( code_block.jcc.block_addr.size() * 8 ) ); 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)
block_vinstrs[ idx ] = code_block.vinstrs[ idx ]; block_vinstrs[idx] = code_block.vinstrs[idx];
vmp2_blocks.push_back( _code_block ); 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 ) + 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) +
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 { 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; code_blocks_size += vmp2_block->next_block_offset;
} ); });
rtn.size = code_blocks_size; rtn.size = code_blocks_size;
rtn.code_block_count = vmp2_blocks.size(); rtn.code_block_count = vmp2_blocks.size();
rtn.vm_enter_offset = vm_entry_rva; rtn.vm_enter_offset = vm_entry_rva;
output.write( reinterpret_cast< const char * >( &rtn ), sizeof( vmp2::v4::rtn_t::size ) + output.write(reinterpret_cast<const char *>(&rtn),
sizeof( vmp2::v4::rtn_t::code_block_count ) + sizeof(vmp2::v4::rtn_t::size) +
sizeof( vmp2::v4::rtn_t::vm_enter_offset ) ); 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 ); std::for_each(vmp2_blocks.begin(), vmp2_blocks.end(),
free( vmp2_block ); [&](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")) {
else if ( parser.exists( "unpack" ) && parser.exists( "out" ) ) engine::unpack_t unpacker(parser.get<std::string>("bin"), module_data);
{
std::vector< std::uint8_t > packed_bin, unpacked_bin;
if ( !umtils->open_binary_file( parser.get< std::string >( "unpack" ), packed_bin ) )
{
std::printf( "> failed to read bin off disk...\n" );
return -1;
}
engine::unpack_t unpacker( packed_bin );
if ( !unpacker.init() ) if (!unpacker.init()) {
{ std::printf("> failed to init unpacker...\n");
std::printf( "> failed to init unpacker...\n" );
return -1; return -1;
} }
if ( !unpacker.unpack( unpacked_bin ) ) if (!unpacker.unpack(unpacked_bin)) {
{ std::printf("> failed to unpack binary... refer to log above...\n");
std::printf( "> failed to unpack binary... refer to log above...\n" );
return -1; return -1;
} }
std::printf( "> writing result to = %s\n", parser.get< std::string >( "out" ).c_str() ); std::printf("> writing result to = %s\n",
std::ofstream output( parser.get< std::string >( "out" ), std::ios::binary ); parser.get<std::string>("out").c_str());
output.write( reinterpret_cast< char * >( unpacked_bin.data() ), unpacked_bin.size() );
std::ofstream output(parser.get<std::string>("out"), std::ios::binary);
output.write(reinterpret_cast<char *>(unpacked_bin.data()),
unpacked_bin.size());
output.close(); output.close();
} } else if (parser.exists("emuall")) {
else if ( parser.exists( "bin" ) && parser.exists( "emuall" ) && parser.exists( "out" ) ) auto entries = vm::locate::get_vm_entries(module_base, image_size);
{
const auto module_base = reinterpret_cast< std::uintptr_t >( std::vector<
LoadLibraryExA( parser.get< std::string >( "bin" ).c_str(), NULL, DONT_RESOLVE_DLL_REFERENCES ) ); std::pair<std::uintptr_t, std::vector<vm::instrs::code_block_t> > >
virt_rtns;
const auto image_base = umtils->image_base( parser.get< std::string >( "bin" ).c_str() );
const auto image_size = NT_HEADER( module_base )->OptionalHeader.SizeOfImage; for (const auto &[vm_enter_offset, encrypted_rva, hndlr_tble] : entries) {
std::printf("> emulating vm enter at rva = 0x%x\n", vm_enter_offset);
auto vm_handler_tables = vm::locate::all_handler_tables( module_base ); vm::ctx_t vm_ctx(module_base, image_base, image_size, vm_enter_offset);
auto vm_enters = vm::locate::all_vm_enters( module_base, vm_handler_tables );
if (!vm_ctx.init()) {
std::vector< std::pair< std::uintptr_t, std::vector< vm::instrs::code_block_t > > > virt_rtns; std::printf(
for ( const auto &[ vm_enter_offset, encrypted_rva ] : vm_enters ) "[!] failed to init vmctx... this can be for many reasons..."
{ " try validating your vm entry rva... make sure the binary is "
std::printf( "> emulating vm enter at rva = 0x%x\n", vm_enter_offset ); "unpacked and is"
vm::ctx_t vm_ctx( module_base, image_base, image_size, vm_enter_offset ); "protected with VMProtect 2...\n");
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; return -1;
} }
vm::emu_t emu( &vm_ctx ); vm::emu_t emu(&vm_ctx);
if ( !emu.init() ) if (!emu.init()) {
{ std::printf("[!] failed to init emulator...\n");
std::printf( "[!] failed to init emulator...\n" );
return -1; return -1;
} }
std::vector< vm::instrs::code_block_t > code_blocks; std::vector<vm::instrs::code_block_t> code_blocks;
if ( !emu.get_trace( code_blocks ) ) if (!emu.get_trace(code_blocks)) {
{ std::printf(
std::printf( "[!] something failed during tracing, review the console for more information...\n" ); "[!] something failed during tracing, review the console for more "
"information...\n");
continue; continue;
} }
std::printf( "> number of blocks = %d\n", code_blocks.size() ); std::printf("> number of blocks = %d\n", code_blocks.size());
virt_rtns.push_back( { vm_enter_offset, code_blocks } ); virt_rtns.push_back({vm_enter_offset, code_blocks});
} }
std::printf( "> traced %d virtual routines...\n", virt_rtns.size() ); std::printf("> traced %d virtual routines...\n", virt_rtns.size());
std::printf( "> serializing results....\n" ); std::printf("> serializing results....\n");
vmp2::v4::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::v4; 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;
@ -280,22 +327,24 @@ int __cdecl main( int argc, const char *argv[] )
file_header.rtn_count = virt_rtns.size(); file_header.rtn_count = virt_rtns.size();
file_header.rtn_offset = image_size + sizeof file_header; file_header.rtn_offset = image_size + sizeof file_header;
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),
output.write( reinterpret_cast< const char * >( module_base ), image_size ); sizeof file_header);
output.write(reinterpret_cast<const char *>(module_base), image_size);
for ( auto &[ vm_enter_offset, virt_rtn ] : virt_rtns ) for (auto &[vm_enter_offset, virt_rtn] : virt_rtns) {
{ vmp2::v4::rtn_t rtn{(u32)virt_rtn.size()};
vmp2::v4::rtn_t rtn{ virt_rtn.size() }; std::vector<vmp2::v4::code_block_t *> vmp2_blocks;
std::vector< vmp2::v4::code_block_t * > vmp2_blocks;
for ( const auto &code_block : virt_rtn ) for (const auto &code_block : virt_rtn) {
{ const auto _code_block_size =
const auto _code_block_size = sizeof vmp2::v4::code_block_t + ( code_block.jcc.block_addr.size() * 8 ) + sizeof(vmp2::v4::code_block_t) +
code_block.vinstrs.size() * sizeof vm::instrs::virt_instr_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 = vmp2::v4::code_block_t *_code_block =
reinterpret_cast< vmp2::v4::code_block_t * >( malloc( _code_block_size ) ); reinterpret_cast<vmp2::v4::code_block_t *>(
malloc(_code_block_size));
// serialize block meta data... // serialize block meta data...
_code_block->vip_begin = code_block.vip_begin; _code_block->vip_begin = code_block.vip_begin;
@ -306,97 +355,45 @@ int __cdecl main( int argc, const char *argv[] )
_code_block->num_block_addrs = code_block.jcc.block_addr.size(); _code_block->num_block_addrs = code_block.jcc.block_addr.size();
// serialize jcc branches... // serialize jcc branches...
for ( auto idx = 0u; idx < code_block.jcc.block_addr.size(); ++idx ) for (auto idx = 0u; idx < code_block.jcc.block_addr.size(); ++idx)
_code_block->branch_addr[ idx ] = code_block.jcc.block_addr[ idx ]; _code_block->branch_addr[idx] = code_block.jcc.block_addr[idx];
auto block_vinstrs = reinterpret_cast< vm::instrs::virt_instr_t * >( auto block_vinstrs = reinterpret_cast<vm::instrs::virt_instr_t *>(
reinterpret_cast< std::uintptr_t >( _code_block ) + sizeof vmp2::v4::code_block_t + reinterpret_cast<std::uintptr_t>(_code_block) +
( code_block.jcc.block_addr.size() * 8 ) ); 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)
block_vinstrs[ idx ] = code_block.vinstrs[ idx ]; block_vinstrs[idx] = code_block.vinstrs[idx];
vmp2_blocks.push_back( _code_block ); vmp2_blocks.push_back(_code_block);
} }
std::size_t code_blocks_size = sizeof( vmp2::v4::rtn_t::size ) + 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::vm_enter_offset) +
sizeof( vmp2::v4::rtn_t::code_block_count ); 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 { 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; code_blocks_size += vmp2_block->next_block_offset;
} ); });
rtn.size = code_blocks_size; rtn.size = code_blocks_size;
rtn.code_block_count = vmp2_blocks.size(); rtn.code_block_count = vmp2_blocks.size();
rtn.vm_enter_offset = vm_enter_offset; rtn.vm_enter_offset = vm_enter_offset;
output.write( reinterpret_cast< const char * >( &rtn ), sizeof( vmp2::v4::rtn_t::size ) + output.write(reinterpret_cast<const char *>(&rtn),
sizeof( vmp2::v4::rtn_t::code_block_count ) + sizeof(vmp2::v4::rtn_t::size) +
sizeof( vmp2::v4::rtn_t::vm_enter_offset ) ); 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 { std::for_each(vmp2_blocks.begin(), vmp2_blocks.end(),
output.write( reinterpret_cast< const char * >( vmp2_block ), vmp2_block->next_block_offset ); [&](vmp2::v4::code_block_t *vmp2_block) -> void {
free( vmp2_block ); output.write(reinterpret_cast<const char *>(vmp2_block),
} ); vmp2_block->next_block_offset);
free(vmp2_block);
});
} }
output.close(); 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 )
{
std::printf( "> emulating vm enter at rva = 0x%x\n", vm_enter_offset );
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" );
return -1;
}
std::printf( "> number of blocks = %d\n", code_blocks.size() );
for ( auto &code_block : code_blocks )
{
for ( const auto &vinstr : code_block.vinstrs )
{
if ( vinstr.operand.has_imm && vinstr.operand.imm.u == const_val )
{
std::printf( "> found constant in vm enter at = 0x%x\n", vm_enter_offset );
std::getchar();
}
}
}
}
}
} }

722
src/unpacker.cpp
Unescape View File

@ -1,273 +1,264 @@
#include <unpacker.hpp> #include <unpacker.hpp>
namespace engine namespace engine {
{ unpack_t::unpack_t(const std::string &module_name,
unpack_t::unpack_t( const std::vector< std::uint8_t > &packed_bin ) const std::vector<std::uint8_t> &packed_bin)
: bin( packed_bin ), uc_ctx( nullptr ), heap_offset( 0ull ), pack_section_offset( 0ull ) : module_name(module_name),
{ bin(packed_bin),
win_img = reinterpret_cast< win::image_t<> * >( bin.data() ); uc_ctx(nullptr),
heap_offset(0ull),
pack_section_offset(0ull) {
win_img = reinterpret_cast<win::image_t<> *>(bin.data());
img_base = win_img->get_nt_headers()->optional_header.image_base; img_base = win_img->get_nt_headers()->optional_header.image_base;
img_size = win_img->get_nt_headers()->optional_header.size_image; img_size = win_img->get_nt_headers()->optional_header.size_image;
std::printf( "> image base = 0x%p, image size = 0x%x\n", img_base, img_size ); std::printf("> image base = 0x%p, image size = 0x%x\n", img_base, img_size);
} }
unpack_t::~unpack_t( void ) unpack_t::~unpack_t(void) {
{ if (uc_ctx) uc_close(uc_ctx);
if ( uc_ctx )
uc_close( uc_ctx );
for ( auto &ptr : uc_hooks ) for (auto &ptr : uc_hooks)
if ( ptr ) if (ptr) delete ptr;
delete ptr; }
}
bool unpack_t::init( void ) bool unpack_t::init(void) {
{
uc_err err; uc_err err;
if ( ( err = uc_open( UC_ARCH_X86, UC_MODE_64, &uc_ctx ) ) ) if ((err = uc_open(UC_ARCH_X86, UC_MODE_64, &uc_ctx))) {
{ std::printf("> uc_open err = %d\n", err);
std::printf( "> uc_open err = %d\n", err );
return false; return false;
} }
if ( ( err = uc_mem_map( uc_ctx, IAT_VECTOR_TABLE, PAGE_4KB, UC_PROT_ALL ) ) ) if ((err = uc_mem_map(uc_ctx, IAT_VECTOR_TABLE, PAGE_4KB, UC_PROT_ALL))) {
{ std::printf("> uc_mem_map iat vector table err = %d\n", err);
std::printf( "> uc_mem_map iat vector table err = %d\n", err );
return false; return false;
} }
if ( ( err = uc_mem_map( uc_ctx, STACK_BASE, STACK_SIZE, UC_PROT_ALL ) ) ) if ((err = uc_mem_map(uc_ctx, STACK_BASE, STACK_SIZE, UC_PROT_ALL))) {
{ std::printf("> uc_mem_map stack err, reason = %d\n", err);
std::printf( "> uc_mem_map stack err, reason = %d\n", err );
return false; return false;
} }
if ( ( err = uc_mem_map( uc_ctx, img_base, img_size, UC_PROT_ALL ) ) ) if ((err = uc_mem_map(uc_ctx, img_base, img_size, UC_PROT_ALL))) {
{ std::printf("> map memory failed, reason = %d\n", err);
std::printf( "> map memory failed, reason = %d\n", err );
return false; return false;
} }
// init iat vector table full of 'ret' instructions... // init iat vector table full of 'ret' instructions...
auto c3_page = malloc( PAGE_4KB ); auto c3_page = malloc(PAGE_4KB);
{ {
memset( c3_page, 0xC3, PAGE_4KB ); memset(c3_page, 0xC3, PAGE_4KB);
if ( ( err = uc_mem_write( uc_ctx, IAT_VECTOR_TABLE, c3_page, PAGE_4KB ) ) ) if ((err = uc_mem_write(uc_ctx, IAT_VECTOR_TABLE, c3_page, PAGE_4KB))) {
{ std::printf("> failed to init iat vector table...\n");
std::printf( "> failed to init iat vector table...\n" ); free(c3_page);
free( c3_page );
return false; return false;
} }
} }
free( c3_page ); free(c3_page);
map_bin.resize( img_size ); map_bin.resize(img_size);
memcpy( map_bin.data(), bin.data(), // copies pe headers (includes section headers) memcpy(map_bin.data(),
win_img->get_nt_headers()->optional_header.size_headers ); bin.data(), // copies pe headers (includes section headers)
win_img->get_nt_headers()->optional_header.size_headers);
win::section_header_t *sec_begin = win_img->get_nt_headers()->get_sections(), win::section_header_t *sec_begin = win_img->get_nt_headers()->get_sections(),
*sec_end = sec_begin + win_img->get_nt_headers()->file_header.num_sections; *sec_end =
sec_begin +
win_img->get_nt_headers()->file_header.num_sections;
std::for_each(
sec_begin, sec_end, [&](const win::section_header_t &sec_header) {
memcpy(map_bin.data() + sec_header.virtual_address,
bin.data() + sec_header.ptr_raw_data, sec_header.size_raw_data);
});
auto basereloc_dir =
win_img->get_directory(win::directory_id::directory_entry_basereloc);
std::for_each( sec_begin, sec_end, [ & ]( const win::section_header_t &sec_header ) { auto reloc_dir = reinterpret_cast<win::reloc_directory_t *>(
memcpy( map_bin.data() + sec_header.virtual_address, bin.data() + sec_header.ptr_raw_data, basereloc_dir->rva + map_bin.data());
sec_header.size_raw_data );
} );
auto basereloc_dir = win_img->get_directory( win::directory_id::directory_entry_basereloc );
auto reloc_dir = reinterpret_cast< win::reloc_directory_t * >( basereloc_dir->rva + map_bin.data() );
win::reloc_block_t *reloc_block = &reloc_dir->first_block; win::reloc_block_t *reloc_block = &reloc_dir->first_block;
// apply relocations to all sections... // apply relocations to all sections...
while ( reloc_block->base_rva && reloc_block->size_block ) while (reloc_block->base_rva && reloc_block->size_block) {
{ std::for_each(
std::for_each( reloc_block->begin(), reloc_block->end(), [ & ]( win::reloc_entry_t &entry ) { reloc_block->begin(), reloc_block->end(),
switch ( entry.type ) [&](win::reloc_entry_t &entry) {
{ switch (entry.type) {
case win::reloc_type_id::rel_based_dir64: case win::reloc_type_id::rel_based_dir64: {
{ auto reloc_at = reinterpret_cast<std::uintptr_t *>(
auto reloc_at = entry.offset + reloc_block->base_rva + map_bin.data());
reinterpret_cast< std::uintptr_t * >( entry.offset + reloc_block->base_rva + map_bin.data() );
*reloc_at = img_base + ((*reloc_at) - img_base);
*reloc_at = img_base + ( ( *reloc_at ) - img_base );
break; break;
} }
default: default:
break; break;
} }
} ); });
reloc_block = reloc_block->next(); reloc_block = reloc_block->next();
} }
// iat hook specific function... // install iat hooks...
for ( auto import_dir = reinterpret_cast< win::import_directory_t * >( for (auto import_dir = reinterpret_cast<win::import_directory_t *>(
win_img->get_directory( win::directory_id::directory_entry_import )->rva + map_bin.data() ); win_img->get_directory(win::directory_id::directory_entry_import)
import_dir->rva_name; ++import_dir ) ->rva +
{ map_bin.data());
for ( auto iat_thunk = import_dir->rva_name; ++import_dir) {
reinterpret_cast< win::image_thunk_data_t<> * >( import_dir->rva_first_thunk + map_bin.data() ); for (auto iat_thunk = reinterpret_cast<win::image_thunk_data_t<> *>(
iat_thunk->address; ++iat_thunk ) import_dir->rva_first_thunk + map_bin.data());
{ iat_thunk->address; ++iat_thunk) {
if ( iat_thunk->is_ordinal ) if (iat_thunk->is_ordinal) continue;
continue;
auto iat_name = reinterpret_cast<win::image_named_import_t *>(
iat_thunk->address + map_bin.data());
auto iat_name = reinterpret_cast< win::image_named_import_t * >( iat_thunk->address + map_bin.data() ); if (iat_hooks.find(iat_name->name) != iat_hooks.end()) {
std::printf("> iat hooking %s to vector table %p\n", iat_name->name,
iat_hooks[iat_name->name].first + IAT_VECTOR_TABLE);
if ( iat_hooks.find( iat_name->name ) != iat_hooks.end() ) iat_thunk->function =
iat_thunk->function = iat_hooks[ iat_name->name ].first + IAT_VECTOR_TABLE; iat_hooks[iat_name->name].first + IAT_VECTOR_TABLE;
}
} }
} }
// map the entire map buffer into unicorn-engine since we have set everything else up... // map the entire map buffer into unicorn-engine since we have set everything
if ( ( err = uc_mem_write( uc_ctx, img_base, map_bin.data(), map_bin.size() ) ) ) // else up...
{ if ((err = uc_mem_write(uc_ctx, img_base, map_bin.data(), map_bin.size()))) {
std::printf( "> failed to write memory... reason = %d\n", err ); std::printf("> failed to write memory... reason = %d\n", err);
return false; return false;
} }
// setup unicorn-engine hooks on IAT vector table, sections with 0 raw size/ptr, and an invalid memory // setup unicorn-engine hooks on IAT vector table, sections with 0 raw
// handler... // size/ptr, and an invalid memory handler...
uc_hooks.push_back( new uc_hook ); uc_hooks.push_back(new uc_hook);
if ( ( err = uc_hook_add( uc_ctx, uc_hooks.back(), UC_HOOK_CODE, &engine::unpack_t::iat_dispatcher, this, if ((err = uc_hook_add(uc_ctx, uc_hooks.back(), UC_HOOK_CODE,
IAT_VECTOR_TABLE, IAT_VECTOR_TABLE + PAGE_4KB ) ) ) (void *)&engine::unpack_t::iat_dispatcher, this,
{ IAT_VECTOR_TABLE, IAT_VECTOR_TABLE + PAGE_4KB))) {
std::printf( "> uc_hook_add error, reason = %d\n", err ); std::printf("> uc_hook_add error, reason = %d\n", err);
return false; return false;
} }
uc_hooks.push_back( new uc_hook ); uc_hooks.push_back(new uc_hook);
if ( ( err = uc_hook_add( uc_ctx, uc_hooks.back(), if ((err = uc_hook_add(
UC_HOOK_MEM_READ_UNMAPPED | UC_HOOK_MEM_WRITE_UNMAPPED | UC_HOOK_MEM_FETCH_UNMAPPED | uc_ctx, uc_hooks.back(),
UC_HOOK_INSN_INVALID, UC_HOOK_MEM_READ_UNMAPPED | UC_HOOK_MEM_WRITE_UNMAPPED |
&engine::unpack_t::invalid_mem, this, true, false ) ) ) UC_HOOK_MEM_FETCH_UNMAPPED | UC_HOOK_INSN_INVALID,
{ (void *)&engine::unpack_t::invalid_mem, this, true, false))) {
std::printf( "> uc_hook_add error, reason = %d\n", err ); std::printf("> uc_hook_add error, reason = %d\n", err);
return false; return false;
} }
// execution break points on all sections that are executable but have no physical size on disk... // execution break points on all sections that are executable but have no
std::for_each( sec_begin, sec_end, [ & ]( win::section_header_t &header ) { // physical size on disk...
if ( !header.ptr_raw_data && !header.size_raw_data && header.characteristics.mem_execute && std::for_each(sec_begin, sec_end, [&](const win::section_header_t &header) {
header.characteristics.mem_write && !header.is_discardable() ) if (!header.ptr_raw_data && !header.size_raw_data &&
{ header.characteristics.mem_execute &&
uc_hooks.push_back( new uc_hook ); header.characteristics.mem_write && !header.is_discardable()) {
if ( ( err = uc_hook_add( uc_ctx, uc_hooks.back(), UC_HOOK_CODE | UC_HOOK_MEM_WRITE, uc_hooks.push_back(new uc_hook);
&engine::unpack_t::unpack_section_callback, this, if ((err = uc_hook_add(
uc_ctx, uc_hooks.back(), UC_HOOK_CODE | UC_HOOK_MEM_WRITE,
(void *)&engine::unpack_t::unpack_section_callback, this,
header.virtual_address + img_base, header.virtual_address + img_base,
header.virtual_address + header.virtual_size + img_base ) ) ) header.virtual_address + header.virtual_size + img_base))) {
{ std::printf("> failed to add hook... reason = %d\n", err);
std::printf( "> failed to add hook... reason = %d\n", err ); return;
return false;
} }
pack_section_offset = header.virtual_address + header.virtual_size; pack_section_offset = header.virtual_address + header.virtual_size;
} }
else if ( header.characteristics.mem_execute ) });
{
uc_hooks.push_back( new uc_hook );
if ( ( err = uc_hook_add( uc_ctx, uc_hooks.back(), UC_HOOK_CODE, &engine::unpack_t::code_exec_callback,
this, header.virtual_address + img_base,
header.virtual_address + header.virtual_size + img_base ) ) )
{
std::printf( "> failed to add hook... reason = %d\n", err );
return false;
}
}
} );
return true; return true;
} }
bool unpack_t::unpack( std::vector< std::uint8_t > &output ) bool unpack_t::unpack(std::vector<std::uint8_t> &output) {
{
uc_err err; uc_err err;
auto nt_headers = win_img->get_nt_headers(); auto nt_headers = win_img->get_nt_headers();
std::uintptr_t rip = nt_headers->optional_header.entry_point + img_base, rsp = STACK_BASE + STACK_SIZE; std::uintptr_t rip = nt_headers->optional_header.entry_point + img_base,
rsp = STACK_BASE + STACK_SIZE;
if ( ( err = uc_reg_write( uc_ctx, UC_X86_REG_RSP, &rsp ) ) ) if ((err = uc_reg_write(uc_ctx, UC_X86_REG_RSP, &rsp))) {
{ std::printf("> uc_reg_write error, reason = %d\n", err);
std::printf( "> uc_reg_write error, reason = %d\n", err );
return false; return false;
} }
if ( ( err = uc_reg_write( uc_ctx, UC_X86_REG_RIP, &rip ) ) ) if ((err = uc_reg_write(uc_ctx, UC_X86_REG_RIP, &rip))) {
{ std::printf("> uc_reg_write error, reason = %d\n", err);
std::printf( "> uc_reg_write error, reason = %d\n", err );
return false; return false;
} }
std::printf( "> beginning execution at = 0x%p\n", rip ); std::printf("> beginning execution at = %p\n", rip);
if ( ( err = uc_emu_start( uc_ctx, rip, 0ull, 0ull, 0ull ) ) ) if ((err = uc_emu_start(uc_ctx, rip, 0ull, 0ull, 0ull))) {
{ std::printf("> error starting emu... reason = %d\n", err);
std::printf( "> error starting emu... reason = %d\n", err );
return false; return false;
} }
output.resize( img_size ); output.resize(img_size);
if ( ( err = uc_mem_read( uc_ctx, img_base, output.data(), output.size() ) ) ) if ((err = uc_mem_read(uc_ctx, img_base, output.data(), output.size()))) {
{ std::printf("> uc_mem_read failed... err = %d\n", err);
std::printf( "> uc_mem_read failed... err = %d\n", err );
return false; return false;
} }
auto output_img = reinterpret_cast< win::image_t<> * >( output.data() ); auto output_img = reinterpret_cast<win::image_t<> *>(output.data());
auto sections = output_img->get_nt_headers()->get_sections(); auto sections = output_img->get_nt_headers()->get_sections();
auto section_cnt = output_img->get_file_header()->num_sections; auto section_cnt = output_img->get_file_header()->num_sections;
// { section virtual address -> vector of section offset to reloc } // { section virtual address -> vector of section offset to reloc }
std::map< std::uint32_t, std::vector< std::uint16_t > > new_relocs; std::map<std::uint32_t, std::vector<std::uint16_t> > new_relocs;
// search executable sections for MOV RAX, 00 00 00 00 00 00 00 00... // search executable sections for MOV RAX, 00 00 00 00 00 00 00 00...
std::for_each( sections, sections + section_cnt, [ & ]( win::section_header_t &header ) { std::for_each(
if ( header.characteristics.mem_execute ) sections, sections + section_cnt, [&](win::section_header_t &header) {
{ if (header.characteristics.mem_execute) {
auto result = output.data() + header.virtual_address; auto result = output.data() + header.virtual_address;
do do {
{ result = reinterpret_cast<std::uint8_t *>(vm::locate::sigscan(
result = reinterpret_cast< std::uint8_t * >( xtils::um_t::get_instance()->sigscan(
result, result,
header.virtual_size - header.virtual_size -
( reinterpret_cast< std::uintptr_t >( result ) - (reinterpret_cast<std::uintptr_t>(result) -
( header.virtual_address + reinterpret_cast< std::uintptr_t >( output.data() ) ) ), (header.virtual_address +
MOV_RAX_0_SIG, MOV_RAX_0_MASK ) ); reinterpret_cast<std::uintptr_t>(output.data()))),
MOV_RAX_0_SIG, MOV_RAX_0_MASK));
if ( result ) if (result) {
{
result += 2; // advance ahead of the 0x48 0xB8... result += 2; // advance ahead of the 0x48 0xB8...
// offset from section begin... // offset from section begin...
auto reloc_offset = auto reloc_offset = (reinterpret_cast<std::uintptr_t>(result)) -
( reinterpret_cast< std::uintptr_t >( result ) ) - reinterpret_cast<std::uintptr_t>(
reinterpret_cast< std::uintptr_t >( output.data() + header.virtual_address ); output.data() + header.virtual_address);
new_relocs[ ( header.virtual_address + reloc_offset ) & ~0xFFFull ].push_back( reloc_offset ); new_relocs[(header.virtual_address + reloc_offset) & ~0xFFFull]
.push_back(reloc_offset);
} }
} while ( result ); } while (result);
} }
header.ptr_raw_data = header.virtual_address; header.ptr_raw_data = header.virtual_address;
header.size_raw_data = header.virtual_size; header.size_raw_data = header.virtual_size;
} ); });
// determines if a relocation block exists for a given page... // determines if a relocation block exists for a given page...
static const auto has_reloc_page = [ & ]( std::uint32_t page ) -> bool { static const auto has_reloc_page = [&](std::uint32_t page) -> bool {
auto img = reinterpret_cast< win::image_t<> * >( output.data() ); auto img = reinterpret_cast<win::image_t<> *>(output.data());
auto sections = img->get_nt_headers()->get_sections(); auto sections = img->get_nt_headers()->get_sections();
auto section_cnt = img->get_file_header()->num_sections; auto section_cnt = img->get_file_header()->num_sections;
auto basereloc_dir = img->get_directory( win::directory_id::directory_entry_basereloc ); auto basereloc_dir =
auto reloc_dir = reinterpret_cast< win::reloc_directory_t * >( basereloc_dir->rva + output.data() ); img->get_directory(win::directory_id::directory_entry_basereloc);
auto reloc_dir = reinterpret_cast<win::reloc_directory_t *>(
basereloc_dir->rva + output.data());
win::reloc_block_t *reloc_block = &reloc_dir->first_block; win::reloc_block_t *reloc_block = &reloc_dir->first_block;
while ( reloc_block->base_rva && reloc_block->size_block ) while (reloc_block->base_rva && reloc_block->size_block) {
{ if (reloc_block->base_rva == page) return true;
if ( reloc_block->base_rva == page )
return true;
reloc_block = reloc_block->next(); reloc_block = reloc_block->next();
} }
@ -277,231 +268,354 @@ namespace engine
// calc size to add new reloc info... // calc size to add new reloc info...
std::size_t resize_cnt = 0ull; std::size_t resize_cnt = 0ull;
for ( const auto &[ reloc_rva, relocs ] : new_relocs ) for (const auto &[reloc_rva, relocs] : new_relocs)
if ( !has_reloc_page( reloc_rva ) ) if (!has_reloc_page(reloc_rva))
resize_cnt += sizeof( win::reloc_block_t ) + ( relocs.size() * sizeof( win::reloc_entry_t ) ); resize_cnt += sizeof(win::reloc_block_t) +
(relocs.size() * sizeof(win::reloc_entry_t));
// last block needs to contain 0 for block_rva and size_block... // last block needs to contain 0 for block_rva and size_block...
if ( resize_cnt ) if (resize_cnt) resize_cnt += sizeof(win::reloc_block_t);
resize_cnt += sizeof win::reloc_block_t;
output.resize( output.size() + resize_cnt ); output.resize(output.size() + resize_cnt);
output_img = reinterpret_cast< win::image_t<> * >( output.data() ); output_img = reinterpret_cast<win::image_t<> *>(output.data());
auto basereloc_dir = output_img->get_directory( win::directory_id::directory_entry_basereloc ); auto basereloc_dir =
auto reloc_dir = reinterpret_cast< win::reloc_directory_t * >( basereloc_dir->rva + output.data() ); output_img->get_directory(win::directory_id::directory_entry_basereloc);
auto reloc_dir = reinterpret_cast<win::reloc_directory_t *>(
basereloc_dir->rva + output.data());
basereloc_dir->size += resize_cnt; basereloc_dir->size += resize_cnt;
for ( const auto &[ reloc_rva, relocs ] : new_relocs ) for (const auto &[reloc_rva, relocs] : new_relocs) {
{ if (has_reloc_page(reloc_rva)) continue;
if ( has_reloc_page( reloc_rva ) )
continue;
win::reloc_block_t *reloc_block = &reloc_dir->first_block; win::reloc_block_t *reloc_block = &reloc_dir->first_block;
while ( reloc_block->base_rva && reloc_block->size_block ) while (reloc_block->base_rva && reloc_block->size_block)
reloc_block = reloc_block->next(); reloc_block = reloc_block->next();
reloc_block->base_rva = reloc_rva; reloc_block->base_rva = reloc_rva;
reloc_block->size_block = relocs.size() * sizeof( win::reloc_entry_t ) + sizeof uint64_t; reloc_block->size_block =
relocs.size() * sizeof(win::reloc_entry_t) + sizeof(uint64_t);
reloc_block->next()->base_rva = 0ull; reloc_block->next()->base_rva = 0ull;
reloc_block->next()->size_block = 0ull; reloc_block->next()->size_block = 0ull;
for ( auto idx = 0u; idx < relocs.size(); ++idx ) for (auto idx = 0u; idx < relocs.size(); ++idx) {
{ reloc_block->entries[idx].type = win::reloc_type_id::rel_based_dir64;
reloc_block->entries[ idx ].type = win::reloc_type_id::rel_based_dir64; reloc_block->entries[idx].offset = relocs[idx];
reloc_block->entries[ idx ].offset = relocs[ idx ];
} }
} }
return true; return true;
} }
void unpack_t::local_alloc_hook( uc_engine *uc_ctx, unpack_t *obj ) void unpack_t::local_alloc_hook(uc_engine *uc_ctx, unpack_t *obj) {
{
uc_err err; uc_err err;
std::uintptr_t rax, rdx; std::uintptr_t rax, rdx;
if ( ( err = uc_reg_read( uc_ctx, UC_X86_REG_RDX, &rdx ) ) ) if ((err = uc_reg_read(uc_ctx, UC_X86_REG_RDX, &rdx))) {
{ std::printf("> failed to read RDX... reason = %d\n", rdx);
std::printf( "> failed to read RDX... reason = %d\n", rdx );
return; return;
} }
auto size = ( ( rdx + PAGE_4KB ) & ~0xFFFull ); auto size = ((rdx + PAGE_4KB) & ~0xFFFull);
if ( ( err = uc_mem_map( uc_ctx, HEAP_BASE + obj->heap_offset, size, UC_PROT_ALL ) ) ) if ((err = uc_mem_map(uc_ctx, HEAP_BASE + obj->heap_offset, size,
{ UC_PROT_ALL))) {
std::printf( "> failed to allocate memory... reason = %d\n", err ); std::printf("> failed to allocate memory... reason = %d\n", err);
return; return;
} }
rax = HEAP_BASE + obj->heap_offset; rax = HEAP_BASE + obj->heap_offset;
obj->heap_offset += size; obj->heap_offset += size;
if ( ( err = uc_reg_write( uc_ctx, UC_X86_REG_RAX, &rax ) ) ) if ((err = uc_reg_write(uc_ctx, UC_X86_REG_RAX, &rax))) {
{ std::printf("> failed to write rax... reason = %d\n", err);
std::printf( "> failed to write rax... reason = %d\n", err );
return; return;
} }
} }
void unpack_t::local_free_hook( uc_engine *uc_ctx, unpack_t *obj ) void unpack_t::local_free_hook(uc_engine *uc_ctx, unpack_t *obj) {
{
uc_err err; uc_err err;
std::uintptr_t rax = 0ull; std::uintptr_t rax = 0ull;
if ( ( err = uc_reg_write( uc_ctx, UC_X86_REG_RAX, &rax ) ) ) if ((err = uc_reg_write(uc_ctx, UC_X86_REG_RAX, &rax))) {
{ std::printf("> failed to write rax... reason = %d\n", err);
std::printf( "> failed to write rax... reason = %d\n", err );
return; return;
} }
} }
void unpack_t::load_library_hook( uc_engine *uc_ctx, unpack_t *obj ) void unpack_t::unmap_view_of_file_hook(uc_engine *uc, unpack_t *obj) {
{ std::uintptr_t rcx, rax = true;
uc_err err; uc_reg_read(uc, UC_X86_REG_RCX, &rcx);
std::uintptr_t rcx = 0ull; uc_reg_write(uc, UC_X86_REG_RAX, &rax);
std::printf("> UnmapViewOfFile(%p)\n", rcx);
}
if ( ( err = uc_reg_read( uc_ctx, UC_X86_REG_RCX, &rcx ) ) ) void unpack_t::close_handle_hook(uc_engine *uc, unpack_t *obj) {
{ std::uintptr_t rcx, rax = true;
std::printf( "> uc_reg_read error, reason = %d\n", err ); uc_reg_read(uc, UC_X86_REG_RCX, &rcx);
uc_reg_write(uc, UC_X86_REG_RAX, &rax);
std::printf("> CloseHandle(%x)\n", rcx);
}
void unpack_t::get_module_file_name_w_hook(uc_engine *uc, unpack_t *obj) {
uc_err err;
std::uintptr_t rcx, rdx, r8;
uc_reg_read(uc, UC_X86_REG_RCX, &rcx);
uc_reg_read(uc, UC_X86_REG_RDX, &rdx);
uc_reg_read(uc, UC_X86_REG_R8, &r8);
std::printf("> GetModuleFileNameW(%p, %p, %d)\n", rcx, rdx, r8);
uc_strcpy(uc, rdx, (char *)obj->module_name.c_str());
std::uint32_t size = obj->module_name.size();
uc_reg_write(uc, UC_X86_REG_RAX, &size);
}
void unpack_t::create_file_w_hook(uc_engine *uc, unpack_t *obj) {
char buff[256];
std::uintptr_t rcx, rax = PACKED_FILE_HANDLE;
uc_reg_read(uc, UC_X86_REG_RCX, &rcx);
uc_strcpy(uc, buff, rcx);
std::printf("> CreateFileW(%s)\n", buff);
uc_reg_write(uc, UC_X86_REG_RAX, &rax);
}
void unpack_t::get_file_size_hook(uc_engine *uc, unpack_t *obj) {
std::uintptr_t rcx, rdx, rax;
uc_reg_read(uc, UC_X86_REG_RCX, &rcx);
uc_reg_read(uc, UC_X86_REG_RDX, &rdx);
std::printf("> GetFileSize(%x, %p)\n", rcx, rdx);
if (rcx == PACKED_FILE_HANDLE) {
rax = obj->bin.size();
uc_reg_write(uc, UC_X86_REG_RAX, &rax);
} else {
std::printf("> asking for file size to unknown handle = %x\n", rcx);
uc_emu_stop(uc);
}
}
void unpack_t::create_file_mapping_hook(uc_engine *uc, unpack_t *obj) {
std::uintptr_t rcx, r8, rax = PACKED_FILE_HANDLE;
uc_reg_read(uc, UC_X86_REG_RCX, &rcx);
uc_reg_read(uc, UC_X86_REG_R8, &r8);
std::printf("> CreateFileMappingW(%x, %x)\n", rcx, r8);
if (rcx == PACKED_FILE_HANDLE) {
uc_reg_write(uc, UC_X86_REG_RAX, &rax);
} else {
std::printf("> asking to create mapping for unknown handle = %x\n", rcx);
uc_emu_stop(uc);
}
}
void unpack_t::map_view_of_file_hook(uc_engine *uc, unpack_t *obj) {
std::uintptr_t rcx, rdx, r8, r9, rax;
uc_reg_read(uc, UC_X86_REG_RCX, &rcx);
uc_reg_read(uc, UC_X86_REG_RDX, &rdx);
uc_reg_read(uc, UC_X86_REG_R8, &r8);
uc_reg_read(uc, UC_X86_REG_R9, &r9);
std::printf("> MapViewOfFile(%x, %x, %x, %x)\n", rcx, rdx, r8, r9);
if (rcx == PACKED_FILE_HANDLE) {
uc_err err;
auto size = ((obj->bin.size() + PAGE_4KB) & ~0xFFFull);
if ((err =
uc_mem_map(uc, HEAP_BASE + obj->heap_offset, size, UC_PROT_ALL))) {
std::printf("> failed to allocate memory... reason = %d\n", err);
return; return;
} }
char buff[ 256 ]; rax = HEAP_BASE + obj->heap_offset;
uc_strcpy( uc_ctx, buff, rcx ); obj->heap_offset += size;
std::printf( "> LoadLibraryA(\"%s\")\n", buff );
auto module_base = reinterpret_cast< std::uintptr_t >( LoadLibraryA( buff ) );
auto module_size = if ((err = uc_mem_write(uc, rax, obj->bin.data(), obj->bin.size()))) {
reinterpret_cast< win::image_t<> * >( module_base )->get_nt_headers()->optional_header.size_image; std::printf("> failed to map view of file... reason = %d\n", err);
return;
}
if ( std::find( obj->loaded_modules.begin(), obj->loaded_modules.end(), module_base ) != if ((err = uc_reg_write(uc, UC_X86_REG_RAX, &rax))) {
obj->loaded_modules.end() ) std::printf("> failed to write rax... reason = %d\n", err);
{
if ( ( err = uc_reg_write( uc_ctx, UC_X86_REG_RAX, &module_base ) ) )
{
std::printf( "> failed to set rax... reason = %d\n", err );
return; return;
} }
} else {
std::printf("> asking to map file for unknown handle = %x\n", rcx);
uc_emu_stop(uc);
} }
else }
{
if ( ( err = uc_mem_map( uc_ctx, module_base, module_size, UC_PROT_ALL ) ) ) void unpack_t::virtual_protect_hook(uc_engine *uc, unpack_t *obj) {
{ std::uintptr_t rcx, rdx, r8, r9, rax = true;
std::printf( "> failed to load library... reason = %d\n", err ); uc_reg_read(uc, UC_X86_REG_RCX, &rcx);
uc_reg_read(uc, UC_X86_REG_RDX, &rdx);
uc_reg_read(uc, UC_X86_REG_R8, &r8);
uc_reg_read(uc, UC_X86_REG_R9, &r9);
std::printf("> VirtualProtect(%p, %x, %x, %p)\n", rcx, rdx, r8, r9);
uc_reg_write(uc, UC_X86_REG_RAX, &rax);
}
void unpack_t::load_library_hook(uc_engine *uc_ctx, unpack_t *obj) {
uc_err err;
std::uintptr_t rcx = 0ull;
if ((err = uc_reg_read(uc_ctx, UC_X86_REG_RCX, &rcx))) {
std::printf("> uc_reg_read error, reason = %d\n", err);
return; return;
} }
if ( ( err = uc_mem_write( uc_ctx, module_base, reinterpret_cast< void * >( module_base ), module_size ) ) ) char buff[256];
{ uc_strcpy(uc_ctx, buff, rcx);
std::printf( "> failed to copy module into emulator... reason = %d\n", err ); std::printf("> LoadLibraryA(\"%s\")\n", buff);
if (!obj->loaded_modules[buff]) {
std::printf("> loading library from disk...\n");
std::vector<std::uint8_t> module_data, tmp;
if (!vm::util::open_binary_file(buff, module_data)) {
std::printf(
"> failed to open a dependency... please put %s in the same folder "
"as vmemu...\n",
buff);
exit(-1);
}
auto img = reinterpret_cast<win::image_t<> *>(module_data.data());
auto image_size = img->get_nt_headers()->optional_header.size_image;
tmp.resize(image_size);
std::memcpy(tmp.data(), module_data.data(), PAGE_4KB);
std::for_each(img->get_nt_headers()->get_sections(),
img->get_nt_headers()->get_sections() +
img->get_nt_headers()->file_header.num_sections,
[&](const auto &section_header) {
std::memcpy(
tmp.data() + section_header.virtual_address,
module_data.data() + section_header.ptr_raw_data,
section_header.size_raw_data);
});
const auto module_base = reinterpret_cast<std::uintptr_t>(tmp.data());
img = reinterpret_cast<win::image_t<> *>(module_base);
const auto image_base = img->get_nt_headers()->optional_header.image_base;
const auto alloc_addr = module_base & ~0xFFFull;
obj->loaded_modules[buff] = alloc_addr;
// install iat hooks...
for (auto import_dir = reinterpret_cast<win::import_directory_t *>(
img->get_directory(win::directory_id::directory_entry_import)
->rva +
module_base);
import_dir->rva_name; ++import_dir) {
for (auto iat_thunk = reinterpret_cast<win::image_thunk_data_t<> *>(
import_dir->rva_first_thunk + module_base);
iat_thunk->address; ++iat_thunk) {
if (iat_thunk->is_ordinal) continue;
auto iat_name = reinterpret_cast<win::image_named_import_t *>(
iat_thunk->address + module_base);
if (obj->iat_hooks.find(iat_name->name) != obj->iat_hooks.end()) {
std::printf("> iat hooking %s to vector table %p\n", iat_name->name,
obj->iat_hooks[iat_name->name].first + IAT_VECTOR_TABLE);
iat_thunk->function =
obj->iat_hooks[iat_name->name].first + IAT_VECTOR_TABLE;
}
}
}
if ((err = uc_mem_map(uc_ctx, alloc_addr, image_size, UC_PROT_ALL))) {
std::printf("> failed to load library... reason = %d\n", err);
return; return;
} }
if ( ( err = uc_reg_write( uc_ctx, UC_X86_REG_RAX, &module_base ) ) ) if ((err = uc_mem_write(uc_ctx, alloc_addr, tmp.data(), image_size))) {
{ std::printf("> failed to copy module into emulator... reason = %d\n",
std::printf( "> failed to set rax... reason = %d\n", err ); err);
return; return;
} }
obj->loaded_modules.push_back( module_base ); if ((err = uc_reg_write(uc_ctx, UC_X86_REG_RAX, &alloc_addr))) {
std::printf("> failed to set rax... reason = %d\n", err);
return;
}
std::printf("> mapped %s to base address %p\n", buff, alloc_addr);
} else {
const auto alloc_addr = obj->loaded_modules[buff];
std::printf("> library already loaded... returning %p...\n", alloc_addr);
if ((err = uc_reg_write(uc_ctx, UC_X86_REG_RAX, &alloc_addr))) {
std::printf("> failed to set rax... reason = %d\n", err);
return;
} }
} }
} // namespace engine
void unpack_t::uc_strcpy( uc_engine *uc_ctx, char *buff, std::uintptr_t addr ) void unpack_t::uc_strcpy(uc_engine *uc_ctx, char *buff, std::uintptr_t addr) {
{
uc_err err; uc_err err;
char i = 0u; char i = 0u;
auto idx = 0ul; auto idx = 0ul;
do do {
{ if ((err = uc_mem_read(uc_ctx, addr + idx, &i, sizeof i))) {
if ( ( err = uc_mem_read( uc_ctx, addr + idx, &i, sizeof i ) ) ) std::printf("[!] error reading string byte... reason = %d\n", err);
break; break;
}
} while ((buff[idx++] = i));
}
} while ( ( buff[ idx++ ] = i ) ); void unpack_t::uc_strcpy(uc_engine *uc, std::uintptr_t addr, char *buff) {
uc_err err;
for (char idx = 0u, c = buff[idx]; buff[idx]; ++idx, c = buff[idx]) {
if ((err = uc_mem_write(uc, addr + idx, &c, sizeof c))) {
std::printf("[!] error writing string byte... reason = %d\n", err);
break;
} }
}
}
bool unpack_t::iat_dispatcher( uc_engine *uc, uint64_t address, uint32_t size, unpack_t *unpack ) bool unpack_t::iat_dispatcher(uc_engine *uc, uint64_t address, uint32_t size,
{ unpack_t *unpack) {
auto vec = address - IAT_VECTOR_TABLE; auto vec = address - IAT_VECTOR_TABLE;
for ( auto &[ iat_name, iat_hook_data ] : unpack->iat_hooks ) for (auto &[iat_name, iat_hook_data] : unpack->iat_hooks) {
{ if (iat_hook_data.first == vec) {
if ( iat_hook_data.first == vec ) iat_hook_data.second(uc, unpack);
{
std::printf( "> hooking import = %s\n", iat_name.c_str() );
iat_hook_data.second( uc, unpack );
return true; return true;
} }
} }
return false; return false;
} }
bool unpack_t::code_exec_callback( uc_engine *uc, uint64_t address, uint32_t size, unpack_t *unpack ) bool unpack_t::unpack_section_callback(uc_engine *uc, uc_mem_type type,
{ uint64_t address, int size,
static ZydisDecoder decoder; int64_t value, unpack_t *unpack) {
static ZydisFormatter formatter; if (address == unpack->pack_section_offset + unpack->img_base) {
static ZydisDecodedInstruction instr; std::printf("> last byte written to unpack section... dumping...\n");
uc_emu_stop(uc);
if ( static std::atomic< bool > once{ false }; !once.exchange( true ) )
{
ZydisDecoderInit( &decoder, ZYDIS_MACHINE_MODE_LONG_64, ZYDIS_ADDRESS_WIDTH_64 );
ZydisFormatterInit( &formatter, ZYDIS_FORMATTER_STYLE_INTEL );
}
auto instr_ptr = reinterpret_cast< void * >( unpack->map_bin.data() + ( address - unpack->img_base ) );
if ( ZYAN_SUCCESS( ZydisDecoderDecodeBuffer( &decoder, instr_ptr, PAGE_4KB, &instr ) ) )
{
if ( instr.mnemonic == ZYDIS_MNEMONIC_CALL && instr.operands[ 0 ].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.operands[ 0 ].reg.value == ZYDIS_REGISTER_RAX )
{
std::uintptr_t rax = 0u, rip = 0u;
uc_reg_read( uc, UC_X86_REG_RAX, &rax );
uc_reg_read( uc, UC_X86_REG_RIP, &rip );
if ( rax > unpack->img_base + unpack->img_size ) // skip calls to kernel32.dll...
{
rip += instr.length;
uc_reg_write( uc, UC_X86_REG_RIP, &rip );
}
}
}
return true;
}
bool unpack_t::unpack_section_callback( uc_engine *uc, uc_mem_type type, uint64_t address, int size, int64_t value,
unpack_t *unpack )
{
if ( address == unpack->pack_section_offset + unpack->img_base )
{
std::printf( "> dumping...\n" );
uc_emu_stop( uc );
return false; return false;
} }
return true; return true;
} }
void unpack_t::invalid_mem( uc_engine *uc, uc_mem_type type, uint64_t address, int size, int64_t value, void unpack_t::invalid_mem(uc_engine *uc, uc_mem_type type, uint64_t address,
unpack_t *unpack ) int size, int64_t value, unpack_t *unpack) {
{ switch (type) {
switch ( type ) case UC_MEM_READ_UNMAPPED: {
{ uc_mem_map(uc, address & ~0xFFFull, PAGE_4KB, UC_PROT_ALL);
case UC_MEM_READ_UNMAPPED: std::printf(">>> reading invalid memory at address = %p, size = 0x%x\n",
std::printf( ">>> reading invalid memory at address = 0x%p, size = 0x%x\n", address, size ); address, size);
break; break;
case UC_MEM_WRITE_UNMAPPED: }
std::printf( ">>> writing invalid memory at address = 0x%p, size = 0x%x, val = 0x%x\n", address, size, case UC_MEM_WRITE_UNMAPPED: {
value ); uc_mem_map(uc, address & ~0xFFFull, PAGE_4KB, UC_PROT_ALL);
std::printf(
">>> writing invalid memory at address = %p, size = 0x%x, val = "
"0x%x\n",
address, size, value);
break; break;
case UC_MEM_FETCH_UNMAPPED: }
{ case UC_MEM_FETCH_UNMAPPED: {
std::printf( ">>> fetching invalid instructions at address = 0x%p\n", address ); std::printf(">>> fetching invalid instructions at address = %p\n",
address);
break; break;
} }
default: default:
break; break;
} }
} }
} // namespace engine } // namespace engine

766
src/vmemu_t.cpp
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