need to add vm::utils::is_mov for ZYDIS_MNEMONIC_MOV/SX/ZX... also need

to make an std::map<zydis_reg_t, unicorn_register>...
master
John Doe 3 years ago
parent 79c3695828
commit eb91191526

@ -51,6 +51,7 @@ set(vmprofiler_SOURCES "")
list(APPEND vmprofiler_SOURCES
"src/vmctx.cpp"
"src/vminstrs.cpp"
"src/vmlocate.cpp"
"src/vmprofiles/jmp.cpp"
"src/vmprofiles/sreg.cpp"

@ -1,23 +1,6 @@
# This file is automatically generated from cmake.toml - DO NOT EDIT
# See https://github.com/build-cpp/cmkr for more information
cmake_minimum_required(VERSION 3.15)
# Regenerate CMakeLists.txt automatically in the root project
set(CMKR_ROOT_PROJECT OFF)
if(CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
set(CMKR_ROOT_PROJECT ON)
# Bootstrap cmkr
include(cmkr.cmake OPTIONAL RESULT_VARIABLE CMKR_INCLUDE_RESULT)
if(CMKR_INCLUDE_RESULT)
cmkr()
endif()
# Enable folder support
set_property(GLOBAL PROPERTY USE_FOLDERS ON)
endif()
# Create a configure-time dependency on cmake.toml to improve IDE support
if(CMKR_ROOT_PROJECT)
configure_file(cmake.toml cmake.toml COPYONLY)

@ -47,7 +47,8 @@ struct vinstr_t {
/// <summary>
/// size varient of the virtual instruction... I.E SREGQ would have a value of
/// "64" here...where the SREGDW varient would have a "32" here...
/// "64" here...where the SREGDW varient would have a "32" here... this is the
/// stack disposition essentially, or the value on the stack...
/// </summary>
u8 size;
@ -140,7 +141,14 @@ extern profiler_t sreg;
/// <summary>
/// unsorted vector of profiles... they get sorted once at runtime...
/// </summary>
inline std::vector<profiler_t*> profiles = {&jmp};
inline std::vector<profiler_t*> profiles = {&jmp, &sreg};
/// <summary>
/// deadstore and opaque branch removal from unicorn engine trace... this is the
/// same algorithm as the one in vm::utils::deobfuscate...
/// </summary>
/// <param name="trace"></param>
void deobfuscate(hndlr_trace_t& trace);
/// <summary>
/// sorts the profiles by descending order of matchers... this will prevent a
@ -148,13 +156,7 @@ inline std::vector<profiler_t*> profiles = {&jmp};
///
/// this function can be called multiple times...
/// </summary>
inline void init() {
if (static std::atomic_bool once = true; once.exchange(false))
std::sort(profiles.begin(), profiles.end(),
[&](profiler_t* a, profiler_t* b) -> bool {
return a->matchers.size() > b->matchers.size();
});
}
void init();
/// <summary>
/// determines the virtual instruction for the vm handler given vsp and vip...
@ -163,46 +165,12 @@ inline void init() {
/// <param name="vsp">vsp native register...</param>
/// <param name="hndlr"></param>
/// <returns>returns vinstr_t structure...</returns>
inline vinstr_t determine(zydis_reg_t& vip,
zydis_reg_t& vsp,
hndlr_trace_t& hndlr) {
const auto& instrs = hndlr.m_instrs;
const auto profile = std::find_if(
profiles.begin(), profiles.end(), [&](profiler_t* profile) -> bool {
for (auto& matcher : profile->matchers) {
const auto matched =
std::find_if(instrs.begin(), instrs.end(),
[&](const emu_instr_t& instr) -> bool {
const auto& i = instr.m_instr;
return matcher(vip, vsp, i);
});
if (matched == instrs.end())
return false;
}
return true;
});
if (profile == profiles.end())
return vinstr_t{mnemonic_t::unknown};
auto result = (*profile)->generate(vip, vsp, hndlr);
return result.has_value() ? result.value() : vinstr_t{mnemonic_t::unknown};
}
vinstr_t determine(zydis_reg_t& vip, zydis_reg_t& vsp, hndlr_trace_t& hndlr);
/// <summary>
/// get profile from mnemonic...
/// </summary>
/// <param name="mnemonic">mnemonic of the profile to get...</param>
/// <returns>pointer to the profile...</returns>
inline profiler_t* get_profile(mnemonic_t mnemonic) {
if (mnemonic == mnemonic_t::unknown)
return nullptr;
const auto res = std::find_if(profiles.begin(), profiles.end(),
[&](profiler_t* profile) -> bool {
return profile->mnemonic == mnemonic;
});
return res == profiles.end() ? nullptr : *res;
}
profiler_t* get_profile(mnemonic_t mnemonic);
} // namespace vm::instrs

@ -0,0 +1,163 @@
#include <vminstrs.hpp>
namespace vm::instrs {
void deobfuscate(hndlr_trace_t& trace) {
static const auto _uses_reg = [](zydis_decoded_operand_t& op,
zydis_reg_t reg) -> bool {
switch (op.type) {
case ZYDIS_OPERAND_TYPE_MEMORY: {
return vm::utils::reg::compare(op.mem.base, reg) ||
vm::utils::reg::compare(op.mem.index, reg);
}
case ZYDIS_OPERAND_TYPE_REGISTER: {
return vm::utils::reg::compare(op.reg.value, reg);
}
default:
break;
}
return false;
};
static const auto _reads = [](zydis_decoded_instr_t& instr,
zydis_reg_t reg) -> bool {
if (instr.operands[0].type == ZYDIS_OPERAND_TYPE_MEMORY &&
vm::utils::reg::compare(instr.operands[0].mem.base, reg))
return true;
for (auto op_idx = 0u; op_idx < instr.operand_count; ++op_idx)
if (instr.operands[op_idx].actions & ZYDIS_OPERAND_ACTION_READ &&
_uses_reg(instr.operands[op_idx], reg))
return true;
return false;
};
static const auto _writes = [](zydis_decoded_instr_t& instr,
zydis_reg_t reg) -> bool {
for (auto op_idx = 0u; op_idx < instr.operand_count; ++op_idx)
// if instruction writes to the specific register...
if (instr.operands[op_idx].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.operands[op_idx].actions & ZYDIS_OPERAND_ACTION_WRITE &&
!(instr.operands[op_idx].actions & ZYDIS_OPERAND_ACTION_READ) &&
vm::utils::reg::compare(instr.operands[op_idx].reg.value, reg))
return true;
return false;
};
std::uint32_t last_size = 0u;
static const std::vector<ZydisMnemonic> blacklist = {
ZYDIS_MNEMONIC_CLC, ZYDIS_MNEMONIC_BT, ZYDIS_MNEMONIC_TEST,
ZYDIS_MNEMONIC_CMP, ZYDIS_MNEMONIC_CMC, ZYDIS_MNEMONIC_STC};
static const std::vector<ZydisMnemonic> whitelist = {
ZYDIS_MNEMONIC_PUSH, ZYDIS_MNEMONIC_POP, ZYDIS_MNEMONIC_CALL,
ZYDIS_MNEMONIC_DIV};
do {
last_size = trace.m_instrs.size();
for (auto itr = trace.m_instrs.begin(); itr != trace.m_instrs.end();
++itr) {
if (std::find(whitelist.begin(), whitelist.end(),
itr->m_instr.mnemonic) != whitelist.end())
continue;
if (std::find(blacklist.begin(), blacklist.end(),
itr->m_instr.mnemonic) != blacklist.end()) {
trace.m_instrs.erase(itr);
break;
}
if (vm::utils::is_jmp(itr->m_instr)) {
trace.m_instrs.erase(itr);
break;
}
zydis_reg_t reg = ZYDIS_REGISTER_NONE;
// look for operands with writes to a register...
for (auto op_idx = 0u; op_idx < itr->m_instr.operand_count; ++op_idx)
if (itr->m_instr.operands[op_idx].type == ZYDIS_OPERAND_TYPE_REGISTER &&
itr->m_instr.operands[op_idx].actions & ZYDIS_OPERAND_ACTION_WRITE)
reg = vm::utils::reg::to64(itr->m_instr.operands[0].reg.value);
// if this current instruction writes to a register, look ahead in the
// instruction stream to see if it gets written too before it gets read...
if (reg != ZYDIS_REGISTER_NONE) {
// find the next place that this register is written too...
auto write_result = std::find_if(itr + 1, trace.m_instrs.end(),
[&](emu_instr_t& instr) -> bool {
return _writes(instr.m_instr, reg);
});
auto read_result = std::find_if(itr + 1, write_result,
[&](emu_instr_t& instr) -> bool {
return _reads(instr.m_instr, reg);
});
// if there is neither a read or a write to this register in the
// instruction stream then we are going to be safe and leave the
// instruction in the stream...
if (read_result == trace.m_instrs.end() &&
write_result == trace.m_instrs.end())
continue;
// if there is no read of the register before the next write... and
// there is a known next write, then remove the instruction from the
// stream...
if (read_result == write_result &&
write_result != trace.m_instrs.end()) {
// if the instruction reads and writes the same register than skip...
if (_reads(read_result->m_instr, reg) &&
_writes(read_result->m_instr, reg))
continue;
trace.m_instrs.erase(itr);
break;
}
}
}
} while (last_size != trace.m_instrs.size());
}
void init() {
if (static std::atomic_bool once = true; once.exchange(false))
std::sort(profiles.begin(), profiles.end(),
[&](profiler_t* a, profiler_t* b) -> bool {
return a->matchers.size() > b->matchers.size();
});
}
vinstr_t determine(zydis_reg_t& vip, zydis_reg_t& vsp, hndlr_trace_t& hndlr) {
const auto& instrs = hndlr.m_instrs;
const auto profile = std::find_if(
profiles.begin(), profiles.end(), [&](profiler_t* profile) -> bool {
for (auto& matcher : profile->matchers) {
const auto matched =
std::find_if(instrs.begin(), instrs.end(),
[&](const emu_instr_t& instr) -> bool {
const auto& i = instr.m_instr;
return matcher(vip, vsp, i);
});
if (matched == instrs.end())
return false;
}
return true;
});
if (profile == profiles.end())
return vinstr_t{mnemonic_t::unknown};
auto result = (*profile)->generate(vip, vsp, hndlr);
return result.has_value() ? result.value() : vinstr_t{mnemonic_t::unknown};
}
profiler_t* get_profile(mnemonic_t mnemonic) {
if (mnemonic == mnemonic_t::unknown)
return nullptr;
const auto res = std::find_if(profiles.begin(), profiles.end(),
[&](profiler_t* profile) -> bool {
return profile->mnemonic == mnemonic;
});
return res == profiles.end() ? nullptr : *res;
}
} // namespace vm::instrs

@ -13,21 +13,22 @@ profiler_t sreg = {
instr.operands[1].type == ZYDIS_OPERAND_TYPE_MEMORY &&
instr.operands[1].mem.base == vsp;
},
// ADD VSP, 8
// ADD VSP, OFFSET
[&](const zydis_reg_t vip,
const zydis_reg_t vsp,
const zydis_decoded_instr_t& instr) -> bool {
return instr.mnemonic == ZYDIS_MNEMONIC_ADD &&
instr.operands[0].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.operands[0].reg.value == vsp &&
instr.operands[1].type == ZYDIS_OPERAND_TYPE_IMMEDIATE &&
instr.operands[1].imm.value.u == 8;
instr.operands[1].type == ZYDIS_OPERAND_TYPE_IMMEDIATE;
},
// MOV REG, [VIP]
[&](const zydis_reg_t vip,
const zydis_reg_t vsp,
const zydis_decoded_instr_t& instr) -> bool {
return instr.mnemonic == ZYDIS_MNEMONIC_MOV &&
return (instr.mnemonic == ZYDIS_MNEMONIC_MOV ||
instr.mnemonic == ZYDIS_MNEMONIC_MOVSX ||
instr.mnemonic == ZYDIS_MNEMONIC_MOVZX) &&
instr.operands[0].type == ZYDIS_OPERAND_TYPE_REGISTER &&
instr.operands[1].type == ZYDIS_OPERAND_TYPE_MEMORY &&
instr.operands[1].mem.base == vip;
@ -44,5 +45,35 @@ profiler_t sreg = {
}}},
[&](zydis_reg_t& vip,
zydis_reg_t& vsp,
hndlr_trace_t& hndlr) -> std::optional<vinstr_t> { return {}; }};
hndlr_trace_t& hndlr) -> std::optional<vinstr_t> {
vinstr_t res;
res.mnemonic = mnemonic_t::sreg;
// locates ADD VSP, VALUE...
const auto add_vsp = std::find_if(
hndlr.m_instrs.begin(), hndlr.m_instrs.end(),
[&](emu_instr_t& instr) -> bool {
const auto& i = instr.m_instr;
return i.mnemonic == ZYDIS_MNEMONIC_ADD &&
i.operands[0].type == ZYDIS_OPERAND_TYPE_REGISTER &&
i.operands[0].reg.value == vsp &&
i.operands[1].type == ZYDIS_OPERAND_TYPE_IMMEDIATE;
});
res.size = add_vsp->m_instr.operands[1].imm.value.u * 8;
// MOV [RSP+REG], REG...
const auto mov_vreg_value = std::find_if(
hndlr.m_instrs.begin(), hndlr.m_instrs.end(),
[&](emu_instr_t& instr) -> bool {
const auto& i = instr.m_instr;
return i.mnemonic == ZYDIS_MNEMONIC_MOV &&
i.operands[0].type == ZYDIS_OPERAND_TYPE_MEMORY &&
i.operands[0].mem.base == ZYDIS_REGISTER_RSP &&
i.operands[0].mem.index != ZYDIS_REGISTER_NONE &&
i.operands[1].type == ZYDIS_OPERAND_TYPE_REGISTER;
});
return res;
}};
}
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