一
****准备阶段****
1.在Steam下载并安装POLYGON
2.找到游戏目录POLYGON\POLYGON\Binaries\Win64
3.找到游戏文件POLYGON-Win64-Shipping.exe
4.拖进IDA等待漫长分析过程
1.Visual Studio 2022
2.C++20
1.Cheat Engine
2.IDA Pro
3.Inject Tool
[!TIP]
游戏有EasyAntiCheat保护
二
****开始****
1、直接打开CE添加这几个地址,确认游戏是基于Dx11
（1）找到ImGui官方源代码,编译一份example_win32_directx11.exe,手动增加一下SwapChain地址输出.官方库地址:https://github.com/ocornut/imgui
（2）运行得到输出:g_pSwapChain:00007FFA24E17000
（3）在CE中搜索并进行指针扫描
2、重新开游戏简单筛选一下，两个应该是都可以用的。
3、最终选用
[!NOTE]
在同一台设备上,Dx虚表位置**“固定”**
[!IMPORTANT]
有关GName的寻找原理请参见前文，本文不做赘述
（1）先通过字符串熟练地找到void __fastcall FNamePool_FNamePool(__int64 a1)
（2）分析交叉引用，如下表：
[!NOTE]
Down
表示当前函数调用了FNamePool_FNamePool
函数。Up
表示FNamePool_FNamePool
函数被当前函数调用。
（1）依次看看几个Up调用内容，不要找太长的函数，也尽量避开明显提到其他组件的函数，要时时刻刻切记我们寻找的只是简单的通过：
static bool bNamePoolInitialized;
alignas(FNamePool) static uint8 NamePoolData[sizeof(FNamePool)];
这种方式进行的构造函数调用，在为数不多的Up调用中寻找到以下符合要求的伪函数：
_DWORD *__fastcall sub_142B04A20(_DWORD *a1, _BYTE *a2)
{
bool v2; // zf
_BYTE *v3; // r8
__int64 v5; // rax
int v6; // eax
RTL_SRWLOCK *v7; // rax
_DWORD *result; // rax
const char *v9; // [rsp+20h] [rbp-18h] BYREF
int v10; // [rsp+28h] [rbp-10h]
char v11; // [rsp+2Ch] [rbp-Ch]
int v12; // [rsp+40h] [rbp+8h] BYREF
int v13; // [rsp+44h] [rbp+Ch]
v2 = *a2 == 0;
v3 = a2 + 2;
v9 = a2 + 2;
v5 = -1i64;
if ( v2 )
{
do
++v5;
while ( v3[v5] );
v11 = 0;
}
else
{
do
++v5;
while ( *(_WORD *)&v3[2 * v5] );
v11 = 1;
}
v10 = v5;
if ( (unsigned int)v5 < 0x400 )
{
if ( byte_148089CF9 )
{
v7 = &stru_1480AD880;
}
else
{
FNamePool_FNamePool((__int64)&stru_1480AD880);
byte_148089CF9 = 1;
}
sub_142B16A60(v7, &v12, &v9);
v13 = v12;
v6 = v12;
}
else
{
v10 = 24;
v9 = "ERROR_NAME_SIZE_EXCEEDED";
v11 = 0;
v6 = sub_142B0CCB0(&v9, 1i64);
}
*a1 = v6;
result = a1;
a1[1] = 0;
return result;
}
（2）GName偏移通过计算0x1480AD880-0x140000000=0x80AD880得到,偏移为0x80AD880
（3）我们开CheatEngine简单检验一下,也确实是这个结果,我们有充分的理由认为,GName地址是**“POLYGON-Win64-Shipping.exe”+0x80AD880**
（4）通过以下代码验证GName正确性：
std::string GetName(uint32_t Id)
{
uint32_t Block = Id >> 16;
uint32_t Offset = Id & 65535;
uint8_t* GameBase = (uint8_t*)GetModuleHandleA("POLYGON-Win64-Shipping.exe");
uint8_t** GName = (uint8_t**)(GameBase + 0x80AD880);
FNameEntry* Info = (FNameEntry*)((GName)[2 + Block] + 2 * Offset);
return std::string(Info->AnsiName, Info->Len);
}
printf("Name:%s\n", GetName(0).c_str());
得到输出：
Name:Non
1、在UnrealEngine.cpp源代码中寻找如下函数：
UWorld* UEngine::GetWorldFromContextObject(const UObject* Object, EGetWorldErrorMode ErrorMode) const
{
if (Object == nullptr)
{
switch (ErrorMode)
{
case EGetWorldErrorMode::Assert:
check(Object);
break;
case EGetWorldErrorMode::LogAndReturnNull:
FFrame::KismetExecutionMessage(TEXT("A null object was passed as a world context object to UEngine::GetWorldFromContextObject()."), ELogVerbosity::Warning);
//UE_LOG(LogEngine, Warning, TEXT("UEngine::GetWorldFromContextObject() passed a nullptr"));
break;
case EGetWorldErrorMode::ReturnNull:
break;
}
return nullptr;
}
bool bSupported = true;
UWorld* World = (ErrorMode == EGetWorldErrorMode::Assert) ? Object->GetWorldChecked(/*out*/ bSupported) : Object->GetWorld();
if (bSupported && (World == nullptr) && (ErrorMode == EGetWorldErrorMode::LogAndReturnNull))
{
FFrame::KismetExecutionMessage(*FString::Printf(TEXT("No world was found for object (%s) passed in to UEngine::GetWorldFromContextObject()."), *GetPathNameSafe(Object)), ELogVerbosity::Warning);
}
return (bSupported ? World : GWorld);
}
它以UWorld*作为返回值,在函数中有大量明文字符串可用来作为特征寻找该函数。
[!NOTE]
如果你发现你在IDA中无法搜索到这些字符串,请设置一下识别的字符串风格,把unicode加进去
2、
.rdata:00000001470E6BE0 aANullObjectWas: ; DATA XREF: sub_144FEE480+1F↑o
.rdata:00000001470E6BE0 text "UTF-16LE", 'A null object was passed as a world context object '
.rdata:00000001470E6C46 text "UTF-16LE", 'to UEngine::GetWorldFromContextObject().',0
__int64 __fastcall sub_144FEE480(__int64 a1, __int64 a2, int a3)
{
__int64 v4; // rsi
__int64 v6; // rax
__int64 v7; // rdi
const wchar_t *v8; // rbx
const wchar_t *v9; // r8
__int64 v10; // rdx
const wchar_t *v11; // [rsp+20h] [rbp-28h] BYREF
int v12; // [rsp+28h] [rbp-20h]
const wchar_t *v13; // [rsp+30h] [rbp-18h] BYREF
int v14; // [rsp+38h] [rbp-10h]
__int64 v15; // [rsp+58h] [rbp+10h] BYREF
v4 = a2;
if ( a2 )
{
LOBYTE(v15) = 1;
if ( a3 == 2 )
v6 = sub_142C63C80(a2, &v15);
else
v6 = (*(__int64 (__fastcall **)(__int64))(*(_QWORD *)a2 + 392i64))(a2);
v7 = v6;
if ( !(_BYTE)v15 )
return qword_1482ACFD0;
if ( !v6 && a3 == 1 )
{
sub_142CD1520(v4, &v13, 0i64);
v8 = &chText;
v9 = &chText;
if ( v14 != (_DWORD)v7 )
v9 = v13;
sub_1429C9990(&v11, L"No world was found for object (%s) passed in to UEngine::GetWorldFromContextObject().", v9);
LOBYTE(v10) = 3;
if ( v12 != (_DWORD)v7 )
v8 = v11;
sub_142CAF290(v8, v10, 0i64);
if ( v11 )
sub_142A062C0();
if ( v13 )
sub_142A062C0();
}
if ( !(_BYTE)v15 )
return qword_1482ACFD0;
return v7;
}
else
{
if ( a3 == 1 )
{
v15 = 0i64;
LOBYTE(a2) = 3;
sub_142CAF290(
L"A null object was passed as a world context object to UEngine::GetWorldFromContextObject().",
a2,
0i64);
}
return 0i64;
}
}
3、锁定return qword_1482ACFD0
，直接计算0x1482ACFD0-0x0x140000000=0x82ACFD0，偏移为0x82ACFD0
（1）还是先看引擎源码，在UObjectHash.cpp，有GObject的定义：
// Global UObject array instance
FUObjectArray GUObjectArray;
（2）分析对GUObjectArray的引用，有很多含有字符串的函数可以作为寻找UObject的跳板，我选择了这个函数：
void UObjectBaseInit()
{
SCOPED_BOOT_TIMING("UObjectBaseInit");
// Zero initialize and later on get value from .ini so it is overridable per game/ platform...
int32 MaxObjectsNotConsideredByGC = 0;
int32 SizeOfPermanentObjectPool = 0;
int32 MaxUObjects = 2 * 1024 * 1024; // Default to ~2M UObjects
bool bPreAllocateUObjectArray = false;
// To properly set MaxObjectsNotConsideredByGC look for "Log: XXX objects as part of root set at end of initial load."
// in your log file. This is being logged from LaunchEnglineLoop after objects have been added to the root set.
// Disregard for GC relies on seekfree loading for interaction with linkers. We also don't want to use it in the Editor, for which
// FPlatformProperties::RequiresCookedData() will be false. Please note that GIsEditor and FApp::IsGame() are not valid at this point.
if (FPlatformProperties::RequiresCookedData())
{
if (IsRunningCookOnTheFly())
{
GCreateGCClusters = false;
}
else
{
GConfig->GetInt(TEXT("/Script/Engine.GarbageCollectionSettings"), TEXT("gc.MaxObjectsNotConsideredByGC"), MaxObjectsNotConsideredByGC, GEngineIni);
// Not used on PC as in-place creation inside bigger pool interacts with the exit purge and deleting UObject directly.
GConfig->GetInt(TEXT("/Script/Engine.GarbageCollectionSettings"), TEXT("gc.SizeOfPermanentObjectPool"), SizeOfPermanentObjectPool, GEngineIni);
}
// Maximum number of UObjects in cooked game
GConfig->GetInt(TEXT("/Script/Engine.GarbageCollectionSettings"), TEXT("gc.MaxObjectsInGame"), MaxUObjects, GEngineIni);
// If true, the UObjectArray will pre-allocate all entries for UObject pointers
GConfig->GetBool(TEXT("/Script/Engine.GarbageCollectionSettings"), TEXT("gc.PreAllocateUObjectArray"), bPreAllocateUObjectArray, GEngineIni);
}
else
{
#if IS_PROGRAM
// Maximum number of UObjects for programs can be low
MaxUObjects = 100000; // Default to 100K for programs
GConfig->GetInt(TEXT("/Script/Engine.GarbageCollectionSettings"), TEXT("gc.MaxObjectsInProgram"), MaxUObjects, GEngineIni);
#else
// Maximum number of UObjects in the editor
GConfig->GetInt(TEXT("/Script/Engine.GarbageCollectionSettings"), TEXT("gc.MaxObjectsInEditor"), MaxUObjects, GEngineIni);
#endif
}
if (MaxObjectsNotConsideredByGC <= 0 && SizeOfPermanentObjectPool > 0)
{
// If permanent object pool is enabled but disregard for GC is disabled, GC will mark permanent object pool objects
// as unreachable and may destroy them so disable permanent object pool too.
// An alternative would be to make GC not mark permanent object pool objects as unreachable but then they would have to
// be considered as root set objects because they could be referencing objects from outside of permanent object pool.
// This would be inconsistent and confusing and also counter productive (the more root set objects the more expensive MarkAsUnreachable phase is).
SizeOfPermanentObjectPool = 0;
UE_LOG(LogInit, Warning, TEXT("Disabling permanent object pool because disregard for GC is disabled (gc.MaxObjectsNotConsideredByGC=%d)."), MaxObjectsNotConsideredByGC);
}
// Log what we're doing to track down what really happens as log in LaunchEngineLoop doesn't report those settings in pristine form.
UE_LOG(LogInit, Log, TEXT("%s for max %d objects, including %i objects not considered by GC, pre-allocating %i bytes for permanent pool."),
bPreAllocateUObjectArray ? TEXT("Pre-allocating") : TEXT("Presizing"),
MaxUObjects, MaxObjectsNotConsideredByGC, SizeOfPermanentObjectPool);
GUObjectAllocator.AllocatePermanentObjectPool(SizeOfPermanentObjectPool);
GUObjectArray.AllocateObjectPool(MaxUObjects, MaxObjectsNotConsideredByGC, bPreAllocateUObjectArray);
#if UE_WITH_OBJECT_HANDLE_LATE_RESOLVE
UE::CoreUObject::Private::InitObjectHandles(GUObjectArray.GetObjectArrayCapacity());
#endif
void InitGarbageElimination();
InitGarbageElimination();
void InitAsyncThread();
InitAsyncThread();
// Note initialized.
Internal::GetUObjectSubsystemInitialised() = true;
UObjectProcessRegistrants();
}
//上边的函数调用下边的函数
void FUObjectArray::AllocateObjectPool(int32 InMaxUObjects, int32 InMaxObjectsNotConsideredByGC, bool bPreAllocateObjectArray)
{
check(IsInGameThread());
MaxObjectsNotConsideredByGC = InMaxObjectsNotConsideredByGC;
// GObjFirstGCIndex is the index at which the garbage collector will start for the mark phase.
// If disregard for GC is enabled this will be set to an invalid value so that later we
// know if disregard for GC pool has already been closed (at least once)
ObjFirstGCIndex = DisregardForGCEnabled() ? -1 : 0;
// Pre-size array.
check(ObjObjects.Num() == 0);
UE_CLOG(InMaxUObjects <= 0, LogUObjectArray, Fatal, TEXT("Max UObject count is invalid. It must be a number that is greater than 0."));
ObjObjects.PreAllocate(InMaxUObjects, bPreAllocateObjectArray);
if (MaxObjectsNotConsideredByGC > 0)
{
ObjObjects.AddRange(MaxObjectsNotConsideredByGC);
}
}
（3）在IDA中定位到源码后，分析这部分：
if (MaxObjectsNotConsideredByGC <= 0 && SizeOfPermanentObjectPool > 0)
{
// If permanent object pool is enabled but disregard for GC is disabled, GC will mark permanent object pool objects
// as unreachable and may destroy them so disable permanent object pool too.
// An alternative would be to make GC not mark permanent object pool objects as unreachable but then they would have to
// be considered as root set objects because they could be referencing objects from outside of permanent object pool.
// This would be inconsistent and confusing and also counter productive (the more root set objects the more expensive MarkAsUnreachable phase is).
SizeOfPermanentObjectPool = 0;
UE_LOG(LogInit, Warning, TEXT("Disabling permanent object pool because disregard for GC is disabled (gc.MaxObjectsNotConsideredByGC=%d)."), MaxObjectsNotConsideredByGC);
}
//对应下面的伪代码 ReName了变量
if ( MaxObjectsNotConsideredByGC <= 0 && SizeOfPermanentObjectPool > 0 )
{
v1 = 0;
SizeOfPermanentObjectPool = 0;
if ( (unsigned __int8)byte_14807DBE0 >= 3u )
{
sub_142A654A0(&byte_14807DBE0, &off_146698318);
v1 = SizeOfPermanentObjectPool;
}
}
（4）在MaxObjectsNotConsideredByGC = InMaxObjectsNotConsideredByGC时，类成员变量被赋值，对应伪代码：
dword_148153F28 = MaxObjectsNotConsideredByGC;
//以下是类成员分布
// /** First index into objects array taken into account for GC. */
// int32 ObjFirstGCIndex;
// /** Index pointing to last object created in range disregarded for GC. */
// int32 ObjLastNonGCIndex;
// /** Maximum number of objects in the disregard for GC Pool */
// int32 MaxObjectsNotConsideredByGC;
（5）定位类索引首地址，就是类全局变量的地址，用0x148153F28-0x8-0x140000000=0x8153F20
看雪ID：Euarno
https://bbs.kanxue.com/user-home-1001108.htm
*本文为看雪论坛优秀文章，由 Euarno 原创，转载请注明来自看雪社区
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