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feat: add base for dynamic junk code obfuscation algorithm

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- Implemented the base for Junk Code dynamic generation.
- Implemented logic for ZydisRegister to GP register conversion.
- Fixed a heuristic analysis feature that stored unused stack registers.
- Ignored reserved stack registers.
- Increased the number of obfuscation passes.
This commit is contained in:
keowu
2025-06-09 21:21:53 -03:00
parent a337df3096
commit c1d6e48682
2 changed files with 28 additions and 247 deletions
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269
RyujinConsole/RyujinConsole/Ryujin/RyujinCore/RyujinObfuscationCore.cc
View File

@@ -26,8 +26,6 @@ BOOL RyujinObfuscationCore::extractUnusedRegisters() {
ZYDIS_REGISTER_RCX,
ZYDIS_REGISTER_RDX,
ZYDIS_REGISTER_RBX,
ZYDIS_REGISTER_RSP,
ZYDIS_REGISTER_RBP,
ZYDIS_REGISTER_RSI,
ZYDIS_REGISTER_RDI,
ZYDIS_REGISTER_R8,
@@ -319,254 +317,37 @@ void RyujinObfuscationCore::insertJunkCode() {
std::uniform_int_distribution<uint32_t> dist(0, 0xFFFF);
auto random_value = dist(gen);
// Each free register has its own junk code (todo: this should be random and generated with some algorithm)
switch (reg) {
/*
Converting ZydisRegister to GP Register based on it's own ID.
*/
// Only x64 registers
if (ZydisRegisterGetClass(reg) != ZYDIS_REGCLASS_GPR64) continue;
case ZYDIS_REGISTER_RAX: {
// Converting ZydisRegister to GB Register Index
auto idx = ZydisRegisterGetId(reg);
// Junk Code Entry
a.push(asmjit::x86::rax);
a.pushf();
a.mov(asmjit::x86::rax, 0);
// Ignore stack unused registers, if the feature for extracting unused register fail
if (idx == 4 /*RSP*/ || idx == 5 /*RBP*/) continue;
a.xor_(asmjit::x86::rax, random_value);
a.inc(asmjit::x86::rax);
a.dec(asmjit::x86::rax);
a.add(asmjit::x86::rax, random_value);
a.sub(asmjit::x86::rax, random_value);
// Converting GB Register Index to a GB Register
auto regx = a.gpz(uint32_t(idx));
// Junk Code Out
a.popf();
a.pop(asmjit::x86::rax);
/*
Gerando Junk Code instructions de maneira randomica
*/
// Todo: Implementar algoritmo para gerar junk code randomico
a.push(regx);
a.pushf();
break;
a.xor_(regx, random_value);
a.inc(regx);
a.dec(regx);
a.add(regx, random_value);
a.sub(regx, random_value);
}
case ZYDIS_REGISTER_RBX: {
// Junk Code Entry
a.push(asmjit::x86::rbx);
a.pushf();
a.mov(asmjit::x86::rbx, 0);
a.rol(asmjit::x86::rbx, random_value);
a.ror(asmjit::x86::rbx, random_value);
a.xchg(asmjit::x86::rbx, asmjit::x86::rbx);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::rbx);
break;
}
case ZYDIS_REGISTER_RCX: {
// Junk Code Entry
a.push(asmjit::x86::rcx);
a.pushf();
a.mov(asmjit::x86::rcx, 0);
a.mov(asmjit::x86::rcx, random_value);
a.add(asmjit::x86::rcx, random_value);
a.mov(asmjit::x86::rcx, random_value);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::rcx);
break;
}
case ZYDIS_REGISTER_RDX: {
// Junk Code Entry
a.push(asmjit::x86::rdx);
a.pushf();
a.mov(asmjit::x86::rdx, 0);
a.add(asmjit::x86::rdx, random_value);
a.shr(asmjit::x86::rdx, random_value);
a.shl(asmjit::x86::rdx, random_value);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::rdx);
break;
}
case ZYDIS_REGISTER_RSI: {
// Junk Code Entry
a.push(asmjit::x86::rsi);
a.pushf();
a.mov(asmjit::x86::rsi, 0);
a.mov(asmjit::x86::rsi, random_value);
a.not_(asmjit::x86::rsi);
a.not_(asmjit::x86::rsi);
a.add(asmjit::x86::rsi, random_value);
a.sub(asmjit::x86::rsi, random_value);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::rsi);
break;
}
case ZYDIS_REGISTER_RDI: {
// Junk Code Entry
a.push(asmjit::x86::rdi);
a.pushf();
a.mov(asmjit::x86::rdi, 0);
a.mov(asmjit::x86::rdi, random_value);
a.xor_(asmjit::x86::rdi, asmjit::x86::rdi);
a.add(asmjit::x86::rdi, random_value);
a.sub(asmjit::x86::rdi, random_value);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::rdi);
break;
}
case ZYDIS_REGISTER_R8: {
// Junk Code Entry
a.push(asmjit::x86::r8);
a.pushf();
a.mov(asmjit::x86::r8, 0);
a.xor_(asmjit::x86::r8, asmjit::x86::r8);
a.mov(asmjit::x86::r8, random_value);
a.or_(asmjit::x86::r8, random_value);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::r8);
break;
}
case ZYDIS_REGISTER_R9: {
// Junk Code Entry
a.push(asmjit::x86::r9);
a.pushf();
a.mov(asmjit::x86::r9, 0);
a.shr(asmjit::x86::r9, random_value);
a.shl(asmjit::x86::r9, random_value);
a.add(asmjit::x86::r9, random_value);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::r9);
break;
}
case ZYDIS_REGISTER_R10: {
// Junk Code Entry
a.push(asmjit::x86::r10);
a.pushf();
a.mov(asmjit::x86::r10, 0);
a.mov(asmjit::x86::r10, random_value);
a.imul(asmjit::x86::r10, random_value);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::r10);
break;
}
case ZYDIS_REGISTER_R11: {
// Junk Code Entry
a.push(asmjit::x86::r11);
a.pushf();
a.mov(asmjit::x86::r11, 0);
a.inc(asmjit::x86::r11);
a.mov(asmjit::x86::r11, random_value);
a.dec(asmjit::x86::r11);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::r11);
break;
}
case ZYDIS_REGISTER_R12: {
// Junk Code Entry
a.push(asmjit::x86::r12);
a.pushf();
a.mov(asmjit::x86::r12, 0);
a.add(asmjit::x86::r12, random_value);
a.sub(asmjit::x86::r12, random_value);
a.mov(asmjit::x86::r12, random_value);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::r12);
break;
}
case ZYDIS_REGISTER_R13: {
// Junk Code Entry
a.push(asmjit::x86::r13);
a.pushf();
a.mov(asmjit::x86::r13, 0);
a.mov(asmjit::x86::r13, random_value);
a.xor_(asmjit::x86::r13, random_value);
a.add(asmjit::x86::r13, random_value);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::r13);
break;
}
case ZYDIS_REGISTER_R14: {
// Junk Code Entry
a.push(asmjit::x86::r14);
a.pushf();
a.mov(asmjit::x86::r14, 0);
a.xor_(asmjit::x86::r14, random_value);
a.xor_(asmjit::x86::r14, random_value);
a.add(asmjit::x86::r14, random_value);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::r14);
break;
}
case ZYDIS_REGISTER_R15: {
// Junk Code Entry
a.push(asmjit::x86::r15);
a.pushf();
a.mov(asmjit::x86::r15, 0);
a.add(asmjit::x86::r15, random_value);
a.add(asmjit::x86::r15, random_value);
a.sub(asmjit::x86::r15, random_value);
a.xor_(asmjit::x86::r15, random_value);
// Junk Code Out
a.popf();
a.pop(asmjit::x86::r15);
break;
}
default: break;
}
// Junk Code Out
a.popf();
a.pop(regx);
}

2
RyujinConsole/RyujinConsole/Ryujin/RyujinCore/RyujinObfuscationCore.hh
View File

@@ -17,7 +17,7 @@ class RyujinObfuscationCore {
private:
const int MAX_PADDING_SPACE_INSTR = 10;
const int MAX_JUNK_GENERATION_ITERATION = 2;
const int MAX_JUNK_GENERATION_ITERATION = 5;
std::vector<ZydisRegister> m_unusedRegisters;
std::vector<RyujinBasicBlock> m_obfuscated_bb;
uintptr_t m_ProcImageBase;