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#include <vmctx.hpp>
namespace vm {
vmctx_t::vmctx_t(std::uintptr_t module_base,
std::uintptr_t image_base,
std::uintptr_t image_size,
std::uintptr_t vm_entry_rva)
: m_module_base(module_base),
m_image_base(image_base),
m_vm_entry_rva(vm_entry_rva),
m_image_size(image_size) {}
bool vmctx_t::init() {
vm::utils::init();
vm::instrs::init();
// flatten and deobfuscate the vm entry...
if (!vm::utils::flatten(m_vm_entry, m_module_base + m_vm_entry_rva))
return false;
vm::utils::deobfuscate(m_vm_entry);
// find mov reg, [rsp+0x90]. this register will be VIP...
const auto vip_fetch = std::find_if(
m_vm_entry.begin(), m_vm_entry.end(),
[&](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;
});
if (vip_fetch == m_vm_entry.end())
return false;
m_vip = vip_fetch->instr.operands[0].reg.value;
// find the register that will be used for the virtual stack...
// mov reg, rsp...
const auto vsp_fetch = std::find_if(
m_vm_entry.begin(), m_vm_entry.end(),
[&](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;
});
if (vsp_fetch == m_vm_entry.end())
return false;
m_vsp = vsp_fetch->instr.operands[0].reg.value;
return true;
}
} // namespace vm