added vmp2 file format v3 (which adds support for virtual jcc's)

merge-requests/9/head
_xeroxz 3 years ago
commit e95ef25371

@ -144,14 +144,14 @@ namespace vm
auto imm_fetch =
std::find_if( vm_handler.begin(), vm_handler.end(), []( const zydis_instr_t &instr_data ) -> bool {
// mov/movsx/movzx rax/eax/ax/al, [rsi]
return ( instr_data.instr.operand_count > 1 &&
return instr_data.instr.operand_count > 1 &&
( instr_data.instr.mnemonic == ZYDIS_MNEMONIC_MOV ||
instr_data.instr.mnemonic == ZYDIS_MNEMONIC_MOVSX ||
instr_data.instr.mnemonic == ZYDIS_MNEMONIC_MOVZX ) &&
instr_data.instr.operands[ 0 ].type == ZYDIS_OPERAND_TYPE_REGISTER &&
util::reg::to64( instr_data.instr.operands[ 0 ].reg.value ) == ZYDIS_REGISTER_RAX &&
instr_data.instr.operands[ 1 ].type == ZYDIS_OPERAND_TYPE_MEMORY &&
instr_data.instr.operands[ 1 ].mem.base == ZYDIS_REGISTER_RSI );
instr_data.instr.operands[ 1 ].mem.base == ZYDIS_REGISTER_RSI;
} );
if ( imm_fetch == vm_handler.end() )

@ -124,32 +124,28 @@ namespace vm
bool get_rva_decrypt( const zydis_routine_t &vm_entry, std::vector< zydis_decoded_instr_t > &transform_instrs )
{
//
// find mov esi, [rsp+0xA0]
//
auto result =
std::find_if( vm_entry.begin(), vm_entry.end(), []( const zydis_instr_t &instr_data ) -> bool {
if ( instr_data.instr.mnemonic == ZYDIS_MNEMONIC_MOV && instr_data.instr.operand_count == 2 &&
return instr_data.instr.mnemonic == ZYDIS_MNEMONIC_MOV &&
instr_data.instr.operands[ 0 ].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr_data.instr.operands[ 0 ].reg.value == ZYDIS_REGISTER_ESI &&
instr_data.instr.operands[ 1 ].type == ZYDIS_OPERAND_TYPE_MEMORY &&
instr_data.instr.operands[ 1 ].mem.base == ZYDIS_REGISTER_RSP &&
instr_data.instr.operands[ 1 ].mem.disp.has_displacement &&
instr_data.instr.operands[ 1 ].mem.disp.value == 0xA0 )
return true;
return false;
instr_data.instr.operands[ 1 ].mem.disp.value == 0xA0;
} );
if ( result == vm_entry.end() )
return false;
//
// find the next three instruction with ESI as the dest...
//
// find the next three instructions with ESI as
// the first operand... and make sure actions & writes...
for ( auto idx = 0u; idx < 3; ++idx )
{
result = std::find_if( ++result, vm_entry.end(), []( const zydis_instr_t &instr_data ) -> bool {
return instr_data.instr.operands[ 0 ].reg.value == ZYDIS_REGISTER_ESI;
return vm::transform::valid( instr_data.instr.mnemonic ) &&
instr_data.instr.operands[ 0 ].actions == ZYDIS_OPERAND_ACTION_WRITE &&
instr_data.instr.operands[ 0 ].reg.value == ZYDIS_REGISTER_ESI;
} );
if ( result == vm_entry.end() )
@ -228,14 +224,13 @@ namespace vm
// instruction rva's ontop of the virtual stack...
result = std::find_if( code_block.vinstrs.rbegin(), code_block.vinstrs.rend(),
[ & ]( const vm::instrs::virt_instr_t &vinstr ) -> bool {
auto profile = vm::handler::get_profile( vinstr.mnemonic_t );
if ( profile && profile->mnemonic == vm::handler::PUSHVSP )
if ( auto profile = vm::handler::get_profile( vinstr.mnemonic_t );
profile && profile->mnemonic == vm::handler::PUSHVSP )
{
const auto possible_block_1 =
code_block_addr( vmctx, vinstr.trace_data.vsp.qword[ 0 ] ^ xor_key );
const auto possible_block_2 =
code_block_addr( vmctx, vinstr.trace_data.vsp.qword[ 1 ] ^ xor_key );
const auto possible_block_1 = code_block_addr(
vmctx, vinstr.trace_data.vsp.qword[ 0 ] ^ xor_key ),
possible_block_2 = code_block_addr(
vmctx, vinstr.trace_data.vsp.qword[ 1 ] ^ xor_key );
// if this returns too many false positives we might have to get
// our hands dirty and look into trying to emulate each branch
@ -253,7 +248,6 @@ namespace vm
if ( result == code_block.vinstrs.rend() )
{
jcc.block_addr[ 0 ] = code_block_addr( vmctx, last_trace );
jcc.has_jcc = false;
jcc.type = jcc_type::absolute;
}

Loading…
Cancel
Save