blew the tires off vmctx for now... fixed a bug in vmlocate... working now...

main
xerox 11 months ago
parent 3061b00f08
commit cbac337a60

@ -1,4 +1,5 @@
---
BasedOnStyle: Chromium
...
...

@ -78,7 +78,6 @@ list(APPEND vmprofiler_SOURCES
"dependencies/vmprofiler/include/vmprofiles.hpp"
"dependencies/vmprofiler/include/vmutils.hpp"
"dependencies/vmprofiler/include/scn.hpp"
"src/vmctx.cpp"
"src/vmlocate.cpp"
"include/vmctx.hpp"
"include/vmlocate.hpp"

@ -3,40 +3,7 @@
#include <vmp2.hpp>
namespace vm {
/// <summary>
/// vm::ctx_t class is used to auto generate vm_entry, calc_jmp, and other
/// per-vm entry information... creating a vm::ctx_t object can make it easier
/// to pass around information pertaining to a given vm entry...
/// </summary>
class ctx_t {
public:
/// <summary>
/// default constructor for vm::ctx_t... all information for a given vm entry
/// must be provided...
/// </summary>
/// <param name="module_base">the linear virtual address of the module
/// base...</param> <param name="image_base">image base from optional nt
/// header... <a
/// href="https://docs.microsoft.com/en-us/windows/win32/api/winnt/ns-winnt-image_optional_header64">IMAGE_OPTIONAL_HEADER64</a>...</param>
/// <param name="image_size">image size from optional nt header... <a
/// href="https://docs.microsoft.com/en-us/windows/win32/api/winnt/ns-winnt-image_optional_header64">IMAGE_OPTIONAL_HEADER64</a>...</param>
/// <param name="vm_entry_rva">relative virtual address from the module base
/// address to the first push prior to a vm entry...</param>
explicit ctx_t(std::uintptr_t module_base, std::uintptr_t image_base,
std::uintptr_t image_size, std::uintptr_t vm_entry_rva);
/// <summary>
/// init all per-vm entry data such as vm_entry, calc_jmp, and vm handlers...
/// </summary>
/// <returns>returns true if no errors...</returns>
bool init();
struct ctx_t {
const std::uintptr_t module_base, image_base, vm_entry_rva, image_size;
/// <summary>
/// the order in which VIP advances...
/// </summary>
vmp2::exec_type_t exec_type;
zydis_routine_t vm_entry;
};
} // namespace vm

@ -5,20 +5,23 @@
#define PUSH_4B_IMM "\x68\x00\x00\x00\x00"
#define PUSH_4B_MASK "x????"
namespace vm::locate
{
inline bool find( const zydis_routine_t &rtn, std::function< bool( const zydis_instr_t & ) > callback )
{
auto res = std::find_if( rtn.begin(), rtn.end(), callback );
return res != rtn.end();
}
namespace vm::locate {
inline bool find(const zydis_routine_t& rtn,
std::function<bool(const zydis_instr_t&)> callback) {
auto res = std::find_if(rtn.begin(), rtn.end(), callback);
return res != rtn.end();
}
struct vm_enter_t
{
std::uint32_t rva;
std::uint32_t encrypted_rva;
};
struct vm_enter_t {
std::uint32_t rva;
std::uint32_t encrypted_rva;
};
std::uintptr_t sigscan( void *base, std::uint32_t size, const char *pattern, const char *mask );
std::vector< vm_enter_t > get_vm_entries( std::uintptr_t module_base, std::uint32_t module_size );
} // namespace vm::locate
std::uintptr_t sigscan(void* base,
std::uint32_t size,
const char* pattern,
const char* mask);
std::vector<vm_enter_t> get_vm_entries(std::uintptr_t module_base,
std::uint32_t module_size);
} // namespace vm::locate

@ -1,19 +0,0 @@
#include <vmctx.hpp>
namespace vm
{
ctx_t::ctx_t( std::uintptr_t module_base, std::uintptr_t image_base, std::uintptr_t image_size,
std::uintptr_t vm_entry_rva )
: module_base( module_base ), image_base( image_base ), image_size( image_size ), vm_entry_rva( vm_entry_rva )
{
}
bool ctx_t::init()
{
if ( !vm::util::flatten( vm_entry, vm_entry_rva + module_base ) )
return false;
vm::util::deobfuscate( vm_entry );
return true;
}
} // namespace vm

@ -1,170 +1,164 @@
#include <vmlocate.hpp>
namespace vm::locate
{
std::uintptr_t sigscan( void *base, std::uint32_t size, const char *pattern, const char *mask )
{
static const auto check_mask = [ & ]( const char *base, const char *pattern, const char *mask ) -> bool {
for ( ; *mask; ++base, ++pattern, ++mask )
if ( *mask == 'x' && *base != *pattern )
return false;
return true;
};
size -= std::strlen( mask );
for ( auto i = 0; i <= size; ++i )
{
void *addr = ( void * )&( ( ( char * )base )[ i ] );
if ( check_mask( ( char * )addr, pattern, mask ) )
return reinterpret_cast< std::uintptr_t >( addr );
}
return {};
namespace vm::locate {
std::uintptr_t sigscan(void* base,
std::uint32_t size,
const char* pattern,
const char* mask) {
static const auto check_mask = [&](const char* base, const char* pattern,
const char* mask) -> bool {
for (; *mask; ++base, ++pattern, ++mask)
if (*mask == 'x' && *base != *pattern)
return false;
return true;
};
size -= std::strlen(mask);
for (auto i = 0; i <= size; ++i) {
void* addr = (void*)&(((char*)base)[i]);
if (check_mask((char*)addr, pattern, mask))
return reinterpret_cast<std::uintptr_t>(addr);
}
return {};
}
std::vector<vm_enter_t> get_vm_entries(std::uintptr_t module_base,
std::uint32_t module_size) {
std::uintptr_t result = module_base;
std::vector<vm_enter_t> entries;
static const auto push_regs = [&](const zydis_routine_t& rtn) -> bool {
for (unsigned reg = ZYDIS_REGISTER_RAX; reg < ZYDIS_REGISTER_R15; ++reg) {
auto res = std::find_if(
rtn.begin(), rtn.end(), [&](const zydis_instr_t& instr) -> bool {
return instr.instr.mnemonic == ZYDIS_MNEMONIC_PUSH &&
instr.instr.operands[0].type ==
ZYDIS_OPERAND_TYPE_REGISTER &&
instr.instr.operands[0].reg.value == reg;
});
// skip RSP push...
if (res == rtn.end() && reg != ZYDIS_REGISTER_RSP)
return false;
}
std::vector< vm_enter_t > get_vm_entries( std::uintptr_t module_base, std::uint32_t module_size )
{
std::uintptr_t result = module_base;
std::vector< vm_enter_t > entries;
static const auto push_regs = [ & ]( const zydis_routine_t &rtn ) -> bool {
for ( unsigned reg = ZYDIS_REGISTER_RAX; reg < ZYDIS_REGISTER_R15; ++reg )
{
auto res = std::find_if( rtn.begin(), rtn.end(), [ & ]( const zydis_instr_t &instr ) -> bool {
return instr.instr.mnemonic == ZYDIS_MNEMONIC_PUSH &&
instr.instr.operands[ 0 ].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.instr.operands[ 0 ].reg.value == reg;
} );
// skip RSP push...
if ( res == rtn.end() && reg != ZYDIS_REGISTER_RSP )
return false;
}
return true;
};
do
{
result = sigscan( ( void * )++result, module_size - ( result - module_base ), PUSH_4B_IMM, PUSH_4B_MASK );
zydis_routine_t rtn;
if ( !scn::executable( module_base, result ) )
continue;
if ( !vm::util::flatten( rtn, result, false, 500, module_base ) )
continue;
// the last instruction in the stream should be a JMP to a register or a return instruction...
const auto &last_instr = rtn[ rtn.size() - 1 ];
if ( !( ( last_instr.instr.mnemonic == ZYDIS_MNEMONIC_JMP &&
last_instr.instr.operands[ 0 ].type == ZYDIS_OPERAND_TYPE_REGISTER ) ||
last_instr.instr.mnemonic == ZYDIS_MNEMONIC_RET ) )
continue;
std::uint8_t num_pushs = 0u;
std::for_each( rtn.begin(), rtn.end(), [ & ]( const zydis_instr_t &instr ) {
if ( instr.instr.mnemonic == ZYDIS_MNEMONIC_PUSH &&
instr.instr.operands[ 0 ].type == ZYDIS_OPERAND_TYPE_IMMEDIATE )
++num_pushs;
} );
/*
only one legit imm pushes for every vm entry...
> 0x822c : push 0xFFFFFFFF890001FA <---
> 0x7fc9 : call xxxxx
> 0x48e4 : push r13
> 0x4690 : push rsi
> 0x4e53 : push r14
> 0x74fb : push rcx
> 0x607c : push rsp
> 0x4926 : pushfq
> 0x4dc2 : push rbp
> 0x5c8c : push r12
> 0x52ac : push r10
> 0x51a5 : push r9
> 0x5189 : push rdx
> 0x7d5f : push r8
> 0x4505 : push rdi
> 0x4745 : push r11
> 0x478b : push rax
> 0x7a53 : push rbx
> 0x500d : push r15
*/
if ( num_pushs != 1 )
continue;
// check for a pushfq...
// > 0x4926 : pushfq <---
if ( !vm::locate::find( rtn, [ & ]( const zydis_instr_t &instr ) -> bool {
return instr.instr.mnemonic == ZYDIS_MNEMONIC_PUSHFQ;
} ) )
continue;
/*
check to see if we push all of these registers...
> 0x48e4 : push r13
> 0x4690 : push rsi
> 0x4e53 : push r14
> 0x74fb : push rcx
> 0x607c : push rsp
> 0x4926 : pushfq
> 0x4dc2 : push rbp
> 0x5c8c : push r12
> 0x52ac : push r10
> 0x51a5 : push r9
> 0x5189 : push rdx
> 0x7d5f : push r8
> 0x4505 : push rdi
> 0x4745 : push r11
> 0x478b : push rax
> 0x7a53 : push rbx
> 0x500d : push r15
*/
if ( !push_regs( rtn ) )
continue;
// check for a mov r13, rax...
if ( !vm::locate::find( rtn, [ & ]( const zydis_instr_t &instr ) -> bool {
return instr.instr.mnemonic == ZYDIS_MNEMONIC_MOV &&
instr.instr.operands[ 0 ].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.instr.operands[ 0 ].reg.value == ZYDIS_REGISTER_R13 &&
instr.instr.operands[ 1 ].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.instr.operands[ 1 ].reg.value == ZYDIS_REGISTER_RAX;
} ) )
continue;
// check for a mov reg, rsp
if ( !vm::locate::find( rtn, [ & ]( const zydis_instr_t &instr ) -> bool {
return instr.instr.mnemonic == ZYDIS_MNEMONIC_MOV &&
instr.instr.operands[ 0 ].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.instr.operands[ 1 ].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.instr.operands[ 1 ].reg.value == ZYDIS_REGISTER_RSP;
} ) )
continue;
// check for a mov reg, [rsp+0x90]
if ( !vm::locate::find( rtn, [ & ]( const zydis_instr_t &instr ) -> bool {
return instr.instr.mnemonic == ZYDIS_MNEMONIC_MOV &&
instr.instr.operands[ 0 ].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.instr.operands[ 1 ].type == ZYDIS_OPERAND_TYPE_MEMORY &&
instr.instr.operands[ 1 ].mem.base == ZYDIS_REGISTER_RSP &&
instr.instr.operands[ 1 ].mem.disp.value == 0x90;
} ) )
continue;
// if code execution gets to here then we can assume this is a legit vm
// entry... its time to build a vm_enter_t... first we check to see if an
// existing entry already exits...
auto push_val = ( std::uint32_t )rtn[ 0 ].instr.operands[ 0 ].imm.value.u;
if ( std::find_if( entries.begin(), entries.end(), [ & ]( const vm_enter_t &vm_enter ) -> bool {
return vm_enter.encrypted_rva == push_val;
} ) != entries.end() )
continue;
vm_enter_t entry{ ( std::uint32_t )( result - module_base ), push_val };
entries.push_back( entry );
} while ( result );
return entries;
}
} // namespace vm::locate
return true;
};
do {
result = sigscan((void*)++result, module_size - (result - module_base),
PUSH_4B_IMM, PUSH_4B_MASK);
zydis_routine_t rtn;
if (!scn::executable(module_base, result))
continue;
if (!vm::util::flatten(rtn, result, false, 500, module_base))
continue;
// the last instruction in the stream should be a JMP to a register or a
// return instruction...
const auto& last_instr = rtn[rtn.size() - 1];
if (!((last_instr.instr.mnemonic == ZYDIS_MNEMONIC_JMP &&
last_instr.instr.operands[0].type == ZYDIS_OPERAND_TYPE_REGISTER) ||
last_instr.instr.mnemonic == ZYDIS_MNEMONIC_RET))
continue;
std::uint8_t num_pushs = 0u;
std::for_each(rtn.begin(), rtn.end(), [&](const zydis_instr_t& instr) {
if (instr.instr.mnemonic == ZYDIS_MNEMONIC_PUSH &&
instr.instr.operands[0].type == ZYDIS_OPERAND_TYPE_IMMEDIATE)
++num_pushs;
});
/*
only one legit imm pushes for every vm entry...
> 0x822c : push 0xFFFFFFFF890001FA <---
> 0x7fc9 : call xxxxx
> 0x48e4 : push r13
> 0x4690 : push rsi
> 0x4e53 : push r14
> 0x74fb : push rcx
> 0x607c : push rsp
> 0x4926 : pushfq
> 0x4dc2 : push rbp
> 0x5c8c : push r12
> 0x52ac : push r10
> 0x51a5 : push r9
> 0x5189 : push rdx
> 0x7d5f : push r8
> 0x4505 : push rdi
> 0x4745 : push r11
> 0x478b : push rax
> 0x7a53 : push rbx
> 0x500d : push r15
*/
if (num_pushs != 1)
continue;
// check for a pushfq...
// > 0x4926 : pushfq <---
if (!vm::locate::find(rtn, [&](const zydis_instr_t& instr) -> bool {
return instr.instr.mnemonic == ZYDIS_MNEMONIC_PUSHFQ;
}))
continue;
/*
check to see if we push all of these registers...
> 0x48e4 : push r13
> 0x4690 : push rsi
> 0x4e53 : push r14
> 0x74fb : push rcx
> 0x607c : push rsp
> 0x4926 : pushfq
> 0x4dc2 : push rbp
> 0x5c8c : push r12
> 0x52ac : push r10
> 0x51a5 : push r9
> 0x5189 : push rdx
> 0x7d5f : push r8
> 0x4505 : push rdi
> 0x4745 : push r11
> 0x478b : push rax
> 0x7a53 : push rbx
> 0x500d : push r15
*/
if (!push_regs(rtn))
continue;
// check for a mov reg, rsp
if (!vm::locate::find(rtn, [&](const zydis_instr_t& instr) -> bool {
return instr.instr.mnemonic == ZYDIS_MNEMONIC_MOV &&
instr.instr.operands[0].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.instr.operands[1].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.instr.operands[1].reg.value == ZYDIS_REGISTER_RSP;
}))
continue;
// check for a mov reg, [rsp+0x90]
if (!vm::locate::find(rtn, [&](const zydis_instr_t& instr) -> bool {
return instr.instr.mnemonic == ZYDIS_MNEMONIC_MOV &&
instr.instr.operands[0].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.instr.operands[1].type == ZYDIS_OPERAND_TYPE_MEMORY &&
instr.instr.operands[1].mem.base == ZYDIS_REGISTER_RSP &&
instr.instr.operands[1].mem.disp.value == 0x90;
}))
continue;
// if code execution gets to here then we can assume this is a legit vm
// entry... its time to build a vm_enter_t... first we check to see if an
// existing entry already exits...
auto push_val = (std::uint32_t)rtn[0].instr.operands[0].imm.value.u;
if (std::find_if(entries.begin(), entries.end(),
[&](const vm_enter_t& vm_enter) -> bool {
return vm_enter.encrypted_rva == push_val;
}) != entries.end())
continue;
vm_enter_t entry{(std::uint32_t)(result - module_base), push_val};
entries.push_back(entry);
} while (result);
return entries;
}
} // namespace vm::locate
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