作者：Leeqwind
作者博客：https://xiaodaozhi.com/kernel/31.html
近期在研究和開發基於虛擬化的虛擬 HOOK 技術。在 Windows 7 x64 環境開發實測期間，發現針對 NtCreateThreadEx 函數的 HOOK 存在問題：該函數大部分情況下變得只返回 0xC00000F2 (STATUS_INVALID_PARAMETER_4) 第 4 個參數無效的狀態碼。這導致系統出現很多問題，大部分的新線程都無法成功創建。為了解決這個問題，在這篇文章中對問題進行追溯，查找到底是哪裡導致的。
經過追蹤：發現位於在 NtAllocateVirtualMemory 中如下位置賦值了提到的錯誤狀態碼：
kd> p nt! ?? ::NNGAKEGL::`string'+0x47703: fffff800`041e171e b8f20000c0 mov eax,0C00000F2h
調用棧如下：
kd> k # Child-SP RetAddr Call Site 00 fffff880`028e7470 fffff800`03e918d3 nt! ?? ::NNGAKEGL::`string'+0x47703 01 fffff880`028e7610 fffff800`03e8de70 nt!KiSystemServiceCopyEnd+0x13 02 fffff880`028e7818 fffff800`04180a63 nt!KiServiceLinkage 03 fffff880`028e7820 fffff800`03e918d3 nt!NtSetInformationProcess+0x4c6 04 fffff880`028e7b70 fffff800`03e8de70 nt!KiSystemServiceCopyEnd+0x13 05 fffff880`028e7d08 fffff800`04180226 nt!KiServiceLinkage 06 fffff880`028e7d10 fffff800`0417e84d nt!RtlCreateUserStack+0x122 07 fffff880`028e7e00 fffff800`0417e47e nt!PspAllocateThread+0x299 08 fffff880`028e8020 fffff800`04182385 nt!PspCreateThread+0x1d2 09 fffff880`028e82a0 fffff880`03ea22ee nt!NtCreateThreadEx+0x25d 0a fffff880`028e89f0 fffff800`03e918d3 DetectModule!Handle_SSDT_NtCreateThreadEx+0x9e 0b fffff880`028e8a70 00000000`76e51d9a nt!KiSystemServiceCopyEnd+0x13 0c 00000000`0366af18 000007fe`fd01b4a3 ntdll!NtCreateThreadEx+0xa 0d 00000000`0366af20 00000000`76bf65b6 KernelBase!CreateRemoteThreadEx+0x163 0e 00000000`0366b3e0 000007fe`f57f7186 kernel32!CreateThreadStub+0x36 0f 00000000`0366b430 00000000`00000000 0x000007fe`f57f7186
具體的調用鏈：
NtCreateThreadEx > PspCreateThread > PspAllocateThread > RtlCreateUserStack > ZwSetInformationProcess > NtSetInformationProcess > ZwAllocateVirtualMemory > NtAllocateVirtualMemory
最終在 NtAllocateVirtualMemory 函數中因其第4個參數的問題導致了 0xC00000F2 的狀態碼。報錯誤碼的指令前面的 10 條執行指令如下：
eb05 jmp nt!NtAllocateVirtualMemory+0x119 (fffff800`04189da9) 488b056092f3ff mov rax,qword ptr [nt!MmHighestUserAddress (fffff800`040c3010)] 48050000ffff add rax,0FFFFFFFFFFFF0000h 483bd8 cmp rbx,rax 0f8755790500 ja nt! ?? ::NNGAKEGL::`string'+0x476f9 (fffff800`041e1714) 488b054a92f3ff mov rax,qword ptr [nt!MmHighestUserAddress (fffff800`040c3010)] 482bc3 sub rax,rbx 482dffff0000 sub rax,0FFFFh 493bc7 cmp rax,r15 0f8246790500 jb nt! ?? ::NNGAKEGL::`string'+0x47703 (fffff800`041e171e) b8f20000c0 mov eax,0C00000F2h
通過 IDA Hex 插件查看：
if ( v147 > MmHighestUserAddress - 0x10000 )
return 0xC00000F0i64;
if ( MmHighestUserAddress - v147 - 0xFFFF < v19 )
return 0xC00000F2i64;
在上面的第二個 if 判斷命中條件，返回了 0xC00000F2 狀態碼。
在 Windbg 中捕獲的該函數的指令執行路徑如下，在分析時由於篇幅關係，在下面的指令片段中均把機器碼左側 64 位地址的高 32 位隱去：
nt!NtAllocateVirtualMemory: `04189c90 4c894c2420 mov qword ptr [rsp+20h],r9 `04189c95 4c89442418 mov qword ptr [rsp+18h],r8 `04189c9a 4889542410 mov qword ptr [rsp+10h],rdx `04189c9f 48894c2408 mov qword ptr [rsp+8],rcx `04189ca4 53 push rbx `04189ca5 56 push rsi `04189ca6 57 push rdi `04189ca7 4154 push r12 `04189ca9 4155 push r13 `04189cab 4156 push r14 `04189cad 4157 push r15 `04189caf 4881ec60010000 sub rsp,160h `04189cb6 4d8bd1 mov r10,r9 `04189cb9 498bc0 mov rax,r8 `04189cbc 4c8bca mov r9,rdx `04189cbf 4c8be9 mov r13,rcx `04189cc2 4d85c0 test r8,r8 `04189cc5 0f8523080000 jne nt!NtAllocateVirtualMemory+0x85e (`0418a4ee) `0418a4ee 4883f820 cmp rax,20h `0418a4f2 0f8223710500 jb nt! ?? ::NNGAKEGL::`string'+0x475f0 (`041e161b) `0418a4f8 488bc8 mov rcx,rax `0418a4fb e82002ceff call nt!RtlFindMostSignificantBit (`03e6a720) `0418a500 440fbec0 movsx r8d,al `0418a504 b83f000000 mov eax,3Fh `0418a509 412bc0 sub eax,r8d `0418a50c 4898 cdqe `0418a50e 48898424b0010000 mov qword ptr [rsp+1B0h],rax `0418a516 4883f835 cmp rax,35h `0418a51a 0f86abf7ffff jbe nt!NtAllocateVirtualMemory+0x3b (`04189ccb) `04189ccb 4533c0 xor r8d,r8d `04189cce 418bf8 mov edi,r8d `04189cd1 654c8b242588010000 mov r12,qword ptr gs:[188h] `04189cda 4d8b5c2470 mov r11,qword ptr [r12+70h] `04189cdf 4c895c2478 mov qword ptr [rsp+78h],r11 `04189ce4 8bb424c0010000 mov esi,dword ptr [rsp+1C0h] `04189ceb 448bf6 mov r14d,esi `04189cee 4183e67f and r14d,7Fh `04189cf2 0fb7050f93f3ff movzx eax,word ptr [nt!KeNumberNodes (`040c3008)] `04189cf9 443bf0 cmp r14d,eax `04189cfc 0f8734790500 ja nt! ?? ::NNGAKEGL::`string'+0x4760b (`041e1636) `04189d02 83e680 and esi,0FFFFFF80h `04189d05 f7c6ffcf07df test esi,0DF07CFFFh `04189d0b 0f852f790500 jne nt! ?? ::NNGAKEGL::`string'+0x47615 (`041e1640) `04189d11 f7c600300800 test esi,83000h `04189d17 0f842d790500 je nt! ?? ::NNGAKEGL::`string'+0x4761f (`041e164a) `04189d1d f7c60000e820 test esi,20E80000h `04189d23 0f85e2090000 jne nt!NtAllocateVirtualMemory+0xa7b (`0418a70b) `04189d29 8b8424c8010000 mov eax,dword ptr [rsp+1C8h] `04189d30 89442460 mov dword ptr [rsp+60h],eax `04189d34 8bc8 mov ecx,eax `04189d36 e8c5bcd1ff call nt!MiMakeProtectionMask (`03ea5a00) `04189d3b 89442474 mov dword ptr [rsp+74h],eax `04189d3f 83f8ff cmp eax,0FFFFFFFFh `04189d42 0f84c2790500 je nt! ?? ::NNGAKEGL::`string'+0x476ef (`041e170a) `04189d48 410fb69424f6010000 movzx edx,byte ptr [r12+1F6h] `04189d51 88542470 mov byte ptr [rsp+70h],dl `04189d55 84d2 test dl,dl `04189d57 7436 je nt!NtAllocateVirtualMemory+0xff (`04189d8f) `04189d8f 498b19 mov rbx,qword ptr [r9] `04189d92 48899c24a0000000 mov qword ptr [rsp+0A0h],rbx `04189d9a 4d8b3a mov r15,qword ptr [r10] `04189d9d 4c897c2468 mov qword ptr [rsp+68h],r15 `04189da2 eb05 jmp nt!NtAllocateVirtualMemory+0x119 (`04189da9) `04189da9 488b056092f3ff mov rax,qword ptr [nt!MmHighestUserAddress (`040c3010)] `04189db0 48050000ffff add rax,0FFFFFFFFFFFF0000h `04189db6 483bd8 cmp rbx,rax `04189db9 0f8755790500 ja nt! ?? ::NNGAKEGL::`string'+0x476f9 (`041e1714) `04189dbf 488b054a92f3ff mov rax,qword ptr [nt!MmHighestUserAddress (`040c3010)] `04189dc6 482bc3 sub rax,rbx `04189dc9 482dffff0000 sub rax,0FFFFh `04189dcf 493bc7 cmp rax,r15 `04189dd2 0f8246790500 jb nt! ?? ::NNGAKEGL::`string'+0x47703 (`041e171e) `041e171e b8f20000c0 mov eax,0C00000F2h
根據上面的指令執行路徑可知，關鍵的寄存器是 r9 寄存器。但在函數稍開始位置將第二個參數寄存器 rdx 的值賦值給 r9 寄存器。
參數4：在賦值 r9 之前，函數將 r9 寄存器賦值給 r10 寄存器；在函數稍後位置將 r10 寄存器存儲的值作為地址取指針長度的值賦值給 r15 寄存器，並且在最後作為 cmp 比較的依據之一，即代碼中的 v19 變量。
參數2：在將 rdx 的值賦值 r9 寄存器之後，在稍後位置將 r9 寄存器的值作為地址取指針長度的值賦值 rbx 寄存器，並通過將 MmHighestUserAddress-rbx-0xFFFF 獲得的值與前面的 r15 寄存器進行大小比較。
函數原型：
NTSTATUS
NTAPI
NtAllocateVirtualMemory(
IN HANDLE ProcessHandle,
IN OUT PVOID *BaseAddress,
IN ULONG_PTR ZeroBits,
IN OUT PSIZE_T RegionSize,
IN ULONG AllocationType,
IN ULONG Protect
);
MmHighestUserAddress 初值：
mov rax, 7FFFFFEFFFFh lea rdx, aSafeboot_0 ; "SAFEBOOT:" mov cs:MmHighestUserAddress, rax mov rax, 7FFFFFF0000h mov cs:MmUserProbeAddress, rax
如果前面相減得到的 rax 值小於 r15 值，那麼報錯。
if ( MmHighestUserAddress - *BaseAddress - 0xFFFF < *RegionSize )
return 0xC00000F2i64;
在報錯指令位置下斷點，截獲到一次報錯的上下文，判斷的兩個寄存器值如下：
kd> r rax, r15 rax=000007fffffe0000 r15=fffffa8000000000
顯而易見地，問題出在 r15 寄存器的值，而 r15 寄存器的值是由 r10 寄存器存儲的指針指向地址的值賦值的。
kd> r r10 r10=fffff880030f8918 kd> dq fffff880030f8918 l1 fffff880`030f8918 fffffa80`00000000
顯而易見地這是一個非常離譜的值，通常此處通過 RegionSize 參數指向域的值確定分配虛擬內存的區域大小，而 0xfffffa8000000000 顯然超過了正常用戶地址空間的範圍。
至於為什麼會傳入這樣無效的值，繼續向上探究：
nt!NtSetInformationProcess: `041d659c fff3 push rbx kd> r rdx rdx=0000000000000029 kd> p nt!NtSetInformationProcess+0x2: `041d659e 56 push rsi `041d659f 57 push rdi `041d65a0 4154 push r12 `041d65a2 4155 push r13 `041d65a4 4156 push r14 `041d65a6 4157 push r15 `041d65a8 4881ec10030000 sub rsp,310h `041d65af 488b052a44e8ff mov rax,qword ptr [nt!_security_cookie (`0405a9e0)] `041d65b6 4833c4 xor rax,rsp `041d65b9 4889842400030000 mov qword ptr [rsp+300h],rax `041d65c1 458bf9 mov r15d,r9d `041d65c4 4d8be0 mov r12,r8 `041d65c7 4c8bd1 mov r10,rcx `041d65ca 48894c2458 mov qword ptr [rsp+58h],rcx `041d65cf 4c898424b0000000 mov qword ptr [rsp+0B0h],r8 `041d65d7 44897c2474 mov dword ptr [rsp+74h],r15d `041d65dc 654c8b342588010000 mov r14,qword ptr gs:[188h] ;; Get _KTHREAD pointer `041d65e5 4c89b42480000000 mov qword ptr [rsp+80h],r14 `041d65ed 418abef6010000 mov dil,byte ptr [r14+1F6h] ;; PreviousMode `041d65f4 33f6 xor esi,esi `041d65f6 403afe cmp dil,sil ;; PreviousMode == KernelMode `041d65f9 0f8461030000 je nt!NtSetInformationProcess+0x3c3 (`041d6960) `041d6960 bb08000000 mov ebx,8 `041d6965 448d6bf9 lea r13d,[rbx-7] `041d6969 e949fdffff jmp nt!NtSetInformationProcess+0x11a (`041d66b7) `041d66b7 83fa17 cmp edx,17h `041d66ba 0f8f76010000 jg nt!NtSetInformationProcess+0x299 (`041d6836) `041d6836 83fa27 cmp edx,27h `041d6839 0f8e2f010000 jle nt!NtSetInformationProcess+0x3d1 (`041d696e) `041d683f 83ea28 sub edx,28h `041d6842 0f84c95f0600 je nt! ?? ::NNGAKEGL::`string'+0x4ce75 (`0423c811) `041d6848 412bd5 sub edx,r13d ; r13d=029h `041d684b 0f8573030000 jne nt!NtSetInformationProcess+0x627 (`041d6bc4) `041d6851 4883cbff or rbx,0FFFFFFFFFFFFFFFFh `041d6855 4c3bd3 cmp r10,rbx `041d6858 0f850b5f0600 jne nt! ?? ::NNGAKEGL::`string'+0x4cdbf (`0423c769) `041d685e 4183ff28 cmp r15d,28h `041d6862 0f85155f0600 jne nt! ?? ::NNGAKEGL::`string'+0x4cdd3 (`0423c77d) `041d6868 403afe cmp dil,sil `041d686b 0f85d8030000 jne nt!NtSetInformationProcess+0x6ac (`041d6c49) `041d6871 4c8bfe mov r15,rsi `041d6874 458b3424 mov r14d,dword ptr [r12] `041d6878 4183fe40 cmp r14d,40h `041d687c 0f87f15e0600 ja nt! ?? ::NNGAKEGL::`string'+0x4cdc9 (`0423c773) `041d6882 418b44240c mov eax,dword ptr [r12+0Ch] `041d6887 410b442408 or eax,dword ptr [r12+8] `041d688c 410b442404 or eax,dword ptr [r12+4] `041d6891 0f85dc5e0600 jne nt! ?? ::NNGAKEGL::`string'+0x4cdc9 (`0423c773) `041d6897 4983c410 add r12,10h `041d689b 49393424 cmp qword ptr [r12],rsi kd> r r12 r12=fffff88003aefd98 kd> p `041d689f 0f84215f0600 je nt! ?? ::NNGAKEGL::`string'+0x4ce23 (`0423c7c6) `041d68a5 49ba1400000080f7ffff mov r10,0FFFFF78000000014h `041d68af 4d8b12 mov r10,qword ptr [r10] `041d68b2 0f31 rdtsc `041d68b4 48c1e220 shl rdx,20h `041d68b8 480bc2 or rax,rdx `041d68bb 4c03d0 add r10,rax `041d68be 4183e21f and r10d,1Fh `041d68c2 4503d5 add r10d,r13d `041d68c5 4d8b1c24 mov r11,qword ptr [r12] ;; 從r12指向地址取值賦給r11 `041d68c9 4c899c24f8000000 mov qword ptr [rsp+0F8h],r11 ;; 為[rsp+0F8h]變量賦值 `041d68d1 65488b042588010000 mov rax,qword ptr gs:[188h] `041d68da 488b4870 mov rcx,qword ptr [rax+70h] `041d68de 0fbaa13c04000011 bt dword ptr [rcx+43Ch],11h `041d68e6 0f823e010000 jb nt!NtSetInformationProcess+0x48d (`041d6a2a) `041d68ec 4d8b4c2408 mov r9,qword ptr [r12+8] `041d68f1 4c3bce cmp r9,rsi `041d68f4 0f85d65e0600 jne nt! ?? ::NNGAKEGL::`string'+0x4ce2d (`0423c7d0) `0423c7d0 4983f920 cmp r9,20h `0423c7d4 7217 jb nt! ?? ::NNGAKEGL::`string'+0x4ce51 (`0423c7ed) `0423c7d6 498bc9 mov rcx,r9 `0423c7d9 e8423fc8ff call nt!RtlFindMostSignificantBit (`03ec0720) `0423c7de 0fbec8 movsx ecx,al `0423c7e1 b83f000000 mov eax,3Fh `0423c7e6 2bc1 sub eax,ecx `0423c7e8 4c63c8 movsxd r9,eax `0423c7eb eb04 jmp nt! ?? ::NNGAKEGL::`string'+0x4ce55 (`0423c7f1) `0423c7f1 4983f935 cmp r9,35h `0423c7f5 0f8739a2f9ff ja nt!NtSetInformationProcess+0x497 (`041d6a34) `0423c7fb e9faa0f9ff jmp nt!NtSetInformationProcess+0x35d (`041d68fa) `041d68fa 4d8d6c2410 lea r13,[r12+10h] `041d68ff 4c896c2420 mov qword ptr [rsp+20h],r13 `041d6904 4533c0 xor r8d,r8d `041d6907 498bd3 mov rdx,r11 `041d690a 418bca mov ecx,r10d `041d690d e8863e0000 call nt!MiScanUserAddressSpace (`041da798) `041d6912 8bc8 mov ecx,eax `041d6914 3bc6 cmp eax,esi `041d6916 7c28 jl nt!NtSetInformationProcess+0x3a3 (`041d6940) `041d6940 3bce cmp ecx,esi `041d6942 0f8cec000000 jl nt!NtSetInformationProcess+0x497 (`041d6a34) `041d6a34 498d542410 lea rdx,[r12+10h] `041d6a39 488932 mov qword ptr [rdx],rsi `041d6a3c 410fbaee0d bts r14d,0Dh `041d6a41 c744242804000000 mov dword ptr [rsp+28h],4 `041d6a49 4489742420 mov dword ptr [rsp+20h],r14d `041d6a4e 4c8d8c24f8000000 lea r9,[rsp+0F8h] ;; 取[rsp+0F8h]變量的地址給r9寄存器 `041d6a56 4d8b442408 mov r8,qword ptr [r12+8] `041d6a5b 488bcb mov rcx,rbx `041d6a5e e87da4d0ff call nt!ZwAllocateVirtualMemory (`03ee0ee0) kd> p nt!NtSetInformationProcess+0x4c6: `041d6a63 8bc8 mov ecx,eax kd> r rax rax=00000000c00000f2 kd> r rsp rsp=fffff88003aef820 kd> dq rsp+0x0f8 l1 fffff880`03aef918 fffff800`00000000 kd> dq fffff88003aefd98 l1 fffff880`03aefd98 fffff800`00000000
函數定義：
NTSTATUS
NTAPI
NtSetInformationProcess (
IN HANDLE ProcessHandle,
IN PROCESSINFOCLASS ProcessInformationClass,
IN PVOID ProcessInformation,
IN ULONG ProcessInformationLength
);
其中第二個參數是定義設置進程信息的類型。根據上面的指令執行路徑得知，這次調用傳遞給該函數的第二個參數值為0x29，根據 PROCESSINFOCLASS 定義：
typedef enum _PROCESSINFOCLASS {
...
ProcessThreadStackAllocation = 0x29, // 0x29, 41
...
} PROCESSINFOCLASS;
進程信息類型為 0x29 時表示設置進程的線程棧分配信息。
在這次 NtSetInformationProcess 函數調用中，可以看到傳入 ZwAllocateVirtualMemory 函數的第四個參數來自它自身第三個參數 r8 寄存器指向的結構體對象基址 +10 偏移的域值。
第三個參數是 ProcessInformation，指向一個由調用者分配的緩衝區，作為用於提供指定的進程信息類型所需的各種數據的結構。
在該函數調用初期查看這個緩衝區中的數據：
kd> dq 0xfffff880`03aefd88 fffff880`03aefd88 00000000`00000000 00000000`00000000 fffff880`03aefd98 fffff880`00000000 00000000`00000000 fffff880`03aefda8 00000000`00000000 00000000`00000000
可以確定的是上級函數傳入 NtSetInformationProcess 的第三個參數時緩衝區中的數據就是這樣的，就是說偏移為 +10h 位置的域其值為 0xFFFFF88000000000 這種異常的值。
所以此時繼續向上探究。在 nt!RtlCreateUserStack 函數首地址下斷點捕獲其調用路徑：
nt!RtlCreateUserStack: `041cf104 4c89442418 mov qword ptr [rsp+18h],r8 `041cf109 4889542410 mov qword ptr [rsp+10h],rdx `041cf10e 48894c2408 mov qword ptr [rsp+8],rcx `041cf113 53 push rbx `041cf114 56 push rsi `041cf115 4154 push r12 `041cf117 4155 push r13 `041cf119 4156 push r14 `041cf11b 4157 push r15 `041cf11d 4881ecb8000000 sub rsp,0B8h `041cf124 4d8be9 mov r13,r9 `041cf127 488bf2 mov rsi,rdx `041cf12a 488bd9 mov rbx,rcx `041cf12d 4d8bf9 mov r15,r9 `041cf130 49c1ef38 shr r15,38h `041cf134 44887c2430 mov byte ptr [rsp+30h],r15b `041cf139 48b8ffffffffffffff00 mov rax,0FFFFFFFFFFFFFFh `041cf143 4c23e8 and r13,rax `041cf146 4c89ac2408010000 mov qword ptr [rsp+108h],r13 `041cf14e 4180ff40 cmp r15b,40h `041cf152 0f8764060400 ja nt! ?? ::NNGAKEGL::`string'+0x7020 (`0420f7bc) `041cf158 4b8d446d00 lea rax,[r13+r13*2] `041cf15d 4889442460 mov qword ptr [rsp+60h],rax `041cf162 65488b042588010000 mov rax,qword ptr gs:[188h] `041cf16b 488b4870 mov rcx,qword ptr [rax+70h] `041cf16f 4c8bb138030000 mov r14,qword ptr [rcx+338h] `041cf176 4c89742458 mov qword ptr [rsp+58h],r14 `041cf17b 4885db test rbx,rbx `041cf17e 0f848b010000 je nt!RtlCreateUserStack+0x20b (`041cf30f) `041cf184 4885d2 test rdx,rdx `041cf187 0f8482010000 je nt!RtlCreateUserStack+0x20b (`041cf30f) `041cf18d b800400000 mov eax,4000h `041cf192 4885db test rbx,rbx `041cf195 480f44d8 cmove rbx,rax `041cf199 483bde cmp rbx,rsi `041cf19c 0f832c060400 jae nt! ?? ::NNGAKEGL::`string'+0x7032 (`0420f7ce) `0420f7ce 488db3ffff0f00 lea rsi,[rbx+0FFFFFh] `0420f7d5 4881e60000f0ff and rsi,0FFFFFFFFFFF00000h `0420f7dc e9c1f9fbff jmp nt!RtlCreateUserStack+0x9e (`041cf1a2) `041cf1a2 498d4dff lea rcx,[r13-1] `041cf1a6 48f7d1 not rcx `041cf1a9 4e8d642bff lea r12,[rbx+r13-1] `041cf1ae 4c23e1 and r12,rcx `041cf1b1 4881c6ffff0000 add rsi,0FFFFh `041cf1b8 4881e60000ffff and rsi,0FFFFFFFFFFFF0000h `041cf1bf 498b8618030000 mov rax,qword ptr [r14+318h] `041cf1c6 48898424a0000000 mov qword ptr [rsp+0A0h],rax `041cf1ce eb05 jmp nt!RtlCreateUserStack+0xd1 (`041cf1d5) `041cf1d5 4885c0 test rax,rax `041cf1d8 0f8503060400 jne nt! ?? ::NNGAKEGL::`string'+0x7045 (`0420f7e1) `041cf1de 410fb6c7 movzx eax,r15b `041cf1e2 89442478 mov dword ptr [rsp+78h],eax `041cf1e6 8364247c00 and dword ptr [rsp+7Ch],0 `041cf1eb 83a4248400000000 and dword ptr [rsp+84h],0 `041cf1f3 83a4248000000000 and dword ptr [rsp+80h],0 `041cf1fb 4889b42488000000 mov qword ptr [rsp+88h],rsi ; assign-> RegionSize `041cf203 4c89842490000000 mov qword ptr [rsp+90h],r8 `041cf20b 41b928000000 mov r9d,28h `041cf211 4c8d442478 lea r8,[rsp+78h] `041cf216 418d5101 lea edx,[r9+1] `041cf21a 4983cfff or r15,0FFFFFFFFFFFFFFFFh `041cf21e 498bcf mov rcx,r15 `041cf221 e83aadd0ff call nt!ZwSetInformationProcess (`03ed9f60) kd> r r8 r8=fffff8800422bd88 kd> dq [r8] fffff880`0422bd88 00000000`00000000 00000000`00000000 fffff880`0422bd98 fffff880`00100000 00000000`00000000 fffff880`0422bda8 00000000`00000384 00000000`00000000 fffff880`0422bdb8 00000000`00000018 fffff880`0422bdd0 kd> r rax=0000000000000000 rbx=fffff88000002000 rcx=ffffffffffffffff rdx=0000000000000029 rsi=fffff88000100000 rdi=0000000000000000 rip=fffff800041cf221 rsp=fffff8800422bd10 rbp=fffffa8004170b30 r8=fffff8800422bd88 r9=0000000000000028 r10=0000000000000001 r11=fffff8800422bde0 r12=fffff88000002000 r13=0000000000001000 r14=000007fffffd7000 r15=ffffffffffffffff iopl=0 nv up ei ng nz na po nc cs=0010 ss=0018 ds=002b es=002b fs=0053 gs=002b efl=00000286
根據執行路徑可知，傳入給 ZwSetInformationProcess 的第三個參數指針指向的是位於 RtlCreateUserStack 棧區域的局部結構體變量。在將結構體地址賦值給 r8 寄存器之前，函數執行對結構體 6 個域賦值操作，其中需要關注的是第 5 個域，即在前面一直追尋的指示 RegionSize 的來源的域，這個域是通過 rsi 寄存器賦值的。
向上追溯，發現在 rsi 寄存器取 rbx+0xFFFFF 地址之後，再經過幾次邏輯與運算：
lea rsi,[rbx+0FFFFFh] and rsi,0FFFFFFFFFFF00000h add rsi,0FFFFh and rsi,0FFFFFFFFFFFF0000h
此時 rbx 的值是 0xFFFFF88000002000，而 rbx 是在函數執行開始時由 rcx 寄存器直接賦值的，而 rcx 寄存器是作為函數的第 1 個參數傳入的。該函數原型如下：
NTSTATUS
NTAPI
RtlCreateUserStack (
_In_opt_ SIZE_T CommittedStackSize,
_In_opt_ SIZE_T MaximumStackSize,
_In_opt_ ULONG_PTR ZeroBits,
_In_ SIZE_T PageSize,
_In_ ULONG_PTR ReserveAlignment,
_Out_ PINITIAL_TEB InitialTeb
);
其中第一個參數是 CommittedStackSize，作為棧的初始提交大小。顯然地在這裡傳入該函數的這個參數就是不尋常的值。那麼繼續向上探究：
nt!PspAllocateThread: `041cd5b4 488bc4 mov rax,rsp `041cd5b7 4c894820 mov qword ptr [rax+20h],r9 `041cd5bb 44884018 mov byte ptr [rax+18h],r8b `041cd5bf 48895010 mov qword ptr [rax+10h],rdx `041cd5c3 48894808 mov qword ptr [rax+8],rcx `041cd5c7 53 push rbx `041cd5c8 56 push rsi `041cd5c9 57 push rdi `041cd5ca 4154 push r12 `041cd5cc 4155 push r13 `041cd5ce 4156 push r14 `041cd5d0 4157 push r15 `041cd5d2 4881ece0010000 sub rsp,1E0h `041cd5d9 458ad0 mov r10b,r8b `041cd5dc 4c8be9 mov r13,rcx `041cd5df 33ff xor edi,edi `041cd5e1 48897c2470 mov qword ptr [rsp+70h],rdi `041cd5e6 4c3bcf cmp r9,rdi `041cd5e9 740b je nt!PspAllocateThread+0x42 (`041cd5f6) `041cd5eb 410fba210f bt dword ptr [r9],0Fh `041cd5f0 0f823c0ff6ff jb nt! ?? ::NNGAKEGL::`string'+0x241f0 (`0412e532) `041cd5f6 4c8ba42460020000 mov r12,qword ptr [rsp+260h] `041cd5fe 65488b042588010000 mov rax,qword ptr gs:[188h] `041cd607 4889842498000000 mov qword ptr [rsp+98h],rax `041cd60f 4c8b842478020000 mov r8,qword ptr [rsp+278h] `041cd617 4189b878010000 mov dword ptr [r8+178h],edi `041cd61e 4588907c010000 mov byte ptr [r8+17Ch],r10b `041cd625 4c8bb42440020000 mov r14,qword ptr [rsp+240h] `041cd62d 4c3bf7 cmp r14,rdi `041cd630 0f848a060000 je nt!PspAllocateThread+0x70b (`041cdcc0) `041cd636 483b0df349f4ff cmp rcx,qword ptr [nt!PsInitialSystemProcess (`04112030)] `041cd63d 0f841a0ff6ff je nt! ?? ::NNGAKEGL::`string'+0x2421f (`0412e55d) `041cd643 483bd7 cmp rdx,rdi `041cd646 0f851a040000 jne nt!PspAllocateThread+0x4b2 (`041cda66) `041cd64c 498b85c8010000 mov rax,qword ptr [r13+1C8h] `041cd653 48f7d8 neg rax `041cd656 1bf6 sbb esi,esi `041cd658 83e658 and esi,58h `041cd65b 41bf98040000 mov r15d,498h `041cd661 4103f7 add esi,r15d `041cd664 488d442458 lea rax,[rsp+58h] `041cd669 4889442440 mov qword ptr [rsp+40h],rax `041cd66e 89742438 mov dword ptr [rsp+38h],esi `041cd672 897c2430 mov dword ptr [rsp+30h],edi `041cd676 89742428 mov dword ptr [rsp+28h],esi `041cd67a 48897c2420 mov qword ptr [rsp+20h],rdi `041cd67f 458aca mov r9b,r10b `041cd682 4c8bc2 mov r8,rdx `041cd685 488b15c449f4ff mov rdx,qword ptr [nt!PsThreadType (`04112050)] `041cd68c 418aca mov cl,r10b `041cd68f e84cd60000 call nt!ObCreateObject (`041dace0) `041cd694 8bd8 mov ebx,eax `041cd696 89442450 mov dword ptr [rsp+50h],eax `041cd69a 3bc7 cmp eax,edi `041cd69c 0f8cc00ef6ff jl nt! ?? ::NNGAKEGL::`string'+0x24224 (`0412e562) `041cd6a2 448bc6 mov r8d,esi `041cd6a5 33d2 xor edx,edx `041cd6a7 488b5c2458 mov rbx,qword ptr [rsp+58h] `041cd6ac 488bcb mov rcx,rbx `041cd6af e8dc61d1ff call nt!memset (`03ee3890) `041cd6b4 413bf7 cmp esi,r15d `041cd6b7 0f87b40ef6ff ja nt! ?? ::NNGAKEGL::`string'+0x24233 (`0412e571) `041cd6bd 4889bb30040000 mov qword ptr [rbx+430h],rdi `041cd6c4 488d8bb0030000 lea rcx,[rbx+3B0h] `041cd6cb 48898c2480000000 mov qword ptr [rsp+80h],rcx `041cd6d3 498b8580010000 mov rax,qword ptr [r13+180h] `041cd6da 488901 mov qword ptr [rcx],rax `041cd6dd 41f6042404 test byte ptr [r12],4 `041cd6e2 0f85c00ef6ff jne nt! ?? ::NNGAKEGL::`string'+0x2426a (`0412e5a8) `041cd6e8 488db338040000 lea rsi,[rbx+438h] `041cd6ef 48893e mov qword ptr [rsi],rdi `041cd6f2 c7834004000007000000 mov dword ptr [rbx+440h],7 `041cd6fc 488d8bc0030000 lea rcx,[rbx+3C0h] `041cd703 33d2 xor edx,edx `041cd705 448d4201 lea r8d,[rdx+1] `041cd709 e88e56d0ff call nt!KeInitializeSemaphore (`03ed2d9c) `041cd70e 488d8b68030000 lea rcx,[rbx+368h] `041cd715 48894908 mov qword ptr [rcx+8],rcx `041cd719 488909 mov qword ptr [rcx],rcx `041cd71c 488d83e8030000 lea rax,[rbx+3E8h] `041cd723 48894008 mov qword ptr [rax+8],rax `041cd727 488900 mov qword ptr [rax],rax `041cd72a 4889bb80040000 mov qword ptr [rbx+480h],rdi `041cd731 4889bb98030000 mov qword ptr [rbx+398h],rdi `041cd738 488d83a0030000 lea rax,[rbx+3A0h] `041cd73f 48894008 mov qword ptr [rax+8],rax `041cd743 488900 mov qword ptr [rax],rax `041cd746 48a11400000080f7ffff mov rax,qword ptr [FFFFF78000000014h] `041cd750 488b4c2458 mov rcx,qword ptr [rsp+58h] `041cd755 48898160030000 mov qword ptr [rcx+360h],rax `041cd75c 48898c24b8000000 mov qword ptr [rsp+0B8h],rcx `041cd764 89bc24c0000000 mov dword ptr [rsp+0C0h],edi `041cd76b f0480fba2e00 lock bts qword ptr [rsi],0 `041cd771 0f823d0ef6ff jb nt! ?? ::NNGAKEGL::`string'+0x24276 (`0412e5b4) `041cd777 4c8b7c2458 mov r15,qword ptr [rsp+58h] `041cd77c 498d9fb8030000 lea rbx,[r15+3B8h] `041cd783 48899c24b0000000 mov qword ptr [rsp+0B0h],rbx `041cd78b 488d9424b8000000 lea rdx,[rsp+0B8h] `041cd793 488b0d2eb4ebff mov rcx,qword ptr [nt!PspCidTable (`04088bc8)] `041cd79a e8a5050000 call nt!ExCreateHandle (`041cdd44) `041cd79f 488903 mov qword ptr [rbx],rax `041cd7a2 483bc7 cmp rax,rdi `041cd7a5 0f84170ef6ff je nt! ?? ::NNGAKEGL::`string'+0x24284 (`0412e5c2) `041cd7ab 4c3bf7 cmp r14,rdi `041cd7ae 0f8429050000 je nt!PspAllocateThread+0x728 (`041cdcdd) `041cd7b4 668bf7 mov si,di `041cd7b7 89742460 mov dword ptr [rsp+60h],esi `041cd7bb 41f6042480 test byte ptr [r12],80h `041cd7c0 0f8592020000 jne nt!PspAllocateThread+0x4a4 (`041cda58) `041cd7c6 41f6042402 test byte ptr [r12],2 `041cd7cb 0f85dc040000 jne nt!PspAllocateThread+0x6f8 (`041cdcad) `041cd7d1 41b808000000 mov r8d,8 `041cd7d7 4c8ba42470020000 mov r12,qword ptr [rsp+270h] `041cd7df 4c3be7 cmp r12,rdi `041cd7e2 0f84c90ef6ff je nt! ?? ::NNGAKEGL::`string'+0x2437b (`0412e6b1) `041cd7e8 4939bd20030000 cmp qword ptr [r13+320h],rdi `041cd7ef 0f8512030000 jne nt!PspAllocateThread+0x552 (`041cdb07) `041cd7f5 41f6042401 test byte ptr [r12],1 `041cd7fa 0f858e0ef6ff jne nt! ?? ::NNGAKEGL::`string'+0x24358 (`0412e68e) `041cd800 bb00100000 mov ebx,1000h `041cd805 41397c2420 cmp dword ptr [r12+20h],edi `041cd80a 0f853e0ef6ff jne nt! ?? ::NNGAKEGL::`string'+0x24318 (`0412e64e) `041cd810 488d942450010000 lea rdx,[rsp+150h] `041cd818 498bcd mov rcx,r13 `041cd81b e8f04bd4ff call nt!KeStackAttachProcess (`03f12410) `041cd820 4c8bb42448020000 mov r14,qword ptr [rsp+248h] `041cd828 4c89742428 mov qword ptr [rsp+28h],r14 `041cd82d 48c744242000000100 mov qword ptr [rsp+20h],10000h `041cd836 4c8bcb mov r9,rbx `041cd839 4d8b442408 mov r8,qword ptr [r12+8] `041cd83e 498b542418 mov rdx,qword ptr [r12+18h] `041cd843 498b4c2410 mov rcx,qword ptr [r12+10h] `041cd848 e8b7180000 call nt!RtlCreateUserStack (`041cf104) kd> r rax=0000000000000000 rbx=0000000000001000 rcx=fffff88000002000 rdx=000007fe00000000 rsi=fffffa8003020000 rdi=0000000000000000 rip=041cd848 rsp=fffff8800422be00 rbp=fffffa8004170b30 r8=0000000000000000 r9=0000000000001000 r10=0000000000000001 r11=fffff8800422bde0 r12=fffff8800422c310 r13=fffffa8004170b30 r14=fffff8800422c340 r15=fffffa8003028b60 kd> dq [rsp+270h] l1 fffff880`0422c070 fffff880`0422c310 kd> dq fffff880`0422c310 l4 fffff880`0422c310 00000000`00000000 00000000`00000000 fffff880`0422c320 fffff880`00002000 000007fe`00000000
根據上面的執行路徑，傳入 RtlCreateUserStack 函數的第一個參數 rcx 寄存器是由 qword ptr [r12+10h] 賦值的。而 r12 寄存器在稍早時候取 [rsp+270h] 指向地址的指針長度的值。
[rsp+270h] 是調用者傳遞給該函數的第 11 個參數。繼續向上追溯：
nt!PspCreateThread: `041cd2ac 48895c2410 mov qword ptr [rsp+10h],rbx `041cd2b1 55 push rbp `041cd2b2 56 push rsi `041cd2b3 57 push rdi `041cd2b4 4154 push r12 `041cd2b6 4155 push r13 `041cd2b8 4156 push r14 `041cd2ba 4157 push r15 `041cd2bc 4881ec40020000 sub rsp,240h `041cd2c3 488b051667e8ff mov rax,qword ptr [nt!_security_cookie (`040539e0)] `041cd2ca 4833c4 xor rax,rsp `041cd2cd 4889842430020000 mov qword ptr [rsp+230h],rax `041cd2d5 4c8bac24c0020000 mov r13,qword ptr [rsp+2C0h] `041cd2dd 488bbc24a0020000 mov rdi,qword ptr [rsp+2A0h] `041cd2e5 4c8bb424a8020000 mov r14,qword ptr [rsp+2A8h] `041cd2ed 4c8bbc24c8020000 mov r15,qword ptr [rsp+2C8h] `041cd2f5 65488b1c2588010000 mov rbx,qword ptr gs:[188h] `041cd2fe 48898c2480000000 mov qword ptr [rsp+80h],rcx `041cd306 488b8c24b0020000 mov rcx,qword ptr [rsp+2B0h] `041cd30e 4c89842488000000 mov qword ptr [rsp+88h],r8 `041cd316 4533c0 xor r8d,r8d `041cd319 48898c2490000000 mov qword ptr [rsp+90h],rcx `041cd321 488b8c24b8020000 mov rcx,qword ptr [rsp+2B8h] `041cd329 498bc1 mov rax,r9 `041cd32c 48898c2498000000 mov qword ptr [rsp+98h],rcx `041cd334 488b8c24e8020000 mov rcx,qword ptr [rsp+2E8h] `041cd33c 89542464 mov dword ptr [rsp+64h],edx `041cd340 458ae0 mov r12b,r8b `041cd343 48894c2470 mov qword ptr [rsp+70h],rcx `041cd348 4d3be8 cmp r13,r8 `041cd34b 7407 je a8 (`041cd354) `041cd34d 448aa3f6010000 mov r12b,byte ptr [rbx+1F6h] `041cd354 4c89442468 mov qword ptr [rsp+68h],r8 `041cd359 be080000c0 mov esi,0C0000008h `041cd35e 493bc0 cmp rax,r8 `041cd361 0f842a020000 je 2e5 (`041cd591) `041cd367 4c89442430 mov qword ptr [rsp+30h],r8 `041cd36c 4c8b05ad4cf4ff mov r8,qword ptr [nt!PsProcessType (`04112020)] `041cd373 488d4c2478 lea rcx,[rsp+78h] `041cd378 48894c2428 mov qword ptr [rsp+28h],rcx `041cd37d 458acc mov r9b,r12b `041cd380 ba02000000 mov edx,2 `041cd385 488bc8 mov rcx,rax `041cd388 c744242044666c74 mov dword ptr [rsp+20h],746C6644h `041cd390 e84ba10000 call nt!ObReferenceObjectByHandleWithTag (`041d74e0) `041cd395 488b6c2478 mov rbp,qword ptr [rsp+78h] `041cd39a 4533c0 xor r8d,r8d `041cd39d 413bc0 cmp eax,r8d `041cd3a0 0f8c9a010000 jl 294 (`041cd540) `041cd3a6 453ae0 cmp r12b,r8b `041cd3a9 0f85bc010000 jne 2bf (`041cd56b) `041cd56b 483b2dbe4af4ff cmp rbp,qword ptr [nt!PsInitialSystemProcess (`04112030)] `041cd572 0f8537feffff jne 103 (`041cd3af) `041cd3af 8b8c24d0020000 mov ecx,dword ptr [rsp+2D0h] `041cd3b6 41b901000000 mov r9d,1 `041cd3bc 418bc0 mov eax,r8d `041cd3bf 4184c9 test r9b,cl `041cd3c2 410f45c1 cmovne eax,r9d `041cd3c6 f6c102 test cl,2 `041cd3c9 0f85ba010000 jne 2dd (`041cd589) `041cd3cf 89442460 mov dword ptr [rsp+60h],eax `041cd3d3 f6c104 test cl,4 `041cd3d6 0f855e200500 jne nt! ?? ::NNGAKEGL::`string'+0x2a7ca (`0421f43a) `041cd3dc f6c108 test cl,8 `041cd3df 0f8598010000 jne 2d1 (`041cd57d) `041cd3e5 66ff8bc4010000 dec word ptr [rbx+1C4h] `041cd3ec 0f0d8d78010000 prefetchw [rbp+178h] `041cd3f3 488b8578010000 mov rax,qword ptr [rbp+178h] `041cd3fa 4883e0fe and rax,0FFFFFFFFFFFFFFFEh `041cd3fe 488d4802 lea rcx,[rax+2] `041cd402 f0480fb18d78010000 lock cmpxchg qword ptr [rbp+178h],rcx `041cd40b 0f8535200500 jne nt! ?? ::NNGAKEGL::`string'+0x2a7d6 (`0421f446) `041cd411 488bcd mov rcx,rbp `041cd414 e8d70ad2ff call nt!ObfReferenceObject (`03eedef0) `041cd419 488b442470 mov rax,qword ptr [rsp+70h] `041cd41e 488b942488000000 mov rdx,qword ptr [rsp+88h] `041cd426 4c8d9c24a0000000 lea r11,[rsp+0A0h] `041cd42e 4d8bce mov r9,r14 `041cd431 458ac4 mov r8b,r12b `041cd434 4c895c2458 mov qword ptr [rsp+58h],r11 `041cd439 4889442450 mov qword ptr [rsp+50h],rax `041cd43e 488d442468 lea rax,[rsp+68h] `041cd443 4889442448 mov qword ptr [rsp+48h],rax `041cd448 488d442460 lea rax,[rsp+60h] `041cd44d 488bcd mov rcx,rbp `041cd450 4889442440 mov qword ptr [rsp+40h],rax `041cd455 488b8424e0020000 mov rax,qword ptr [rsp+2E0h] `041cd45d 4889442438 mov qword ptr [rsp+38h],rax `041cd462 488b8424d8020000 mov rax,qword ptr [rsp+2D8h] `041cd46a 4889442430 mov qword ptr [rsp+30h],rax `041cd46f 4c897c2428 mov qword ptr [rsp+28h],r15 `041cd474 4c896c2420 mov qword ptr [rsp+20h],r13 `041cd479 e836010000 call nt!PspAllocateThread (`041cd5b4) kd> dq [rsp+50h] l1 fffff880`04286070 fffff880`04286310 kd> dq fffff880`04286310 l4 fffff880`04286310 00000000`00000000 00000000`00000000 fffff880`04286320 fffff880`00000000 00000144`00000000
觀察上面的執行路徑不難發現傳遞給 PspAllocateThread 函數的第 11 個參數來自 PspCreateThread 函數的 [rsp+2E8h] 第 14 個參數，而在當前函數中沒有進行任何修改和取值訪問。
而在 NtCreateThreadEx 函數中由於虛擬化設置問題暫時無法進行單步追蹤。所以通過 IDA 對其彙編代碼進行分析，再加上通過 PspAllocateThread 函數返回后的上下文，對運行現場的環境進一步的追蹤：
`403701DF loc_1403701DF: `403701DF mov [rsp+748h+var_6D8], bl `403701E3 mov rax, [rsp+748h+arg_40] `403701EB mov [rsp+748h+var_6C8], rax `403701F3 mov rax, [rsp+748h+arg_48] `403701FB mov [rsp+748h+var_6C0], rax `40370203 mov rax, [rsp+748h+arg_38] `4037020B mov [rsp+748h+var_6D0], rax `40370210 mov [rsp+748h+var_6B8], ebx `40370217 xor edx, edx ; Val `40370219 mov r8d, 150h ; Size `4037021F lea rcx, [rsp+748h+var_198] ; Dst `40370227 call memset `4037022C test rdi, rdi `4037022F jz short loc_140370285 `40370231 mov rax, gs:188h `4037023A lea r9, [rsp+748h+var_198] `40370242 mov r8d, 1 `40370248 mov dl, [rax+1F6h] `4037024E mov rcx, rdi `40370251 call PspBuildCreateProcessContext `40370256 test eax, eax `40370258 js loc_140370396 `4037025E lea rax, [rsp+748h+var_70] `40370266 bt dword ptr [rsp+748h+var_198], 0Ch `4037026F cmovnb rax, rbx `40370273 mov rbx, rax `40370276 bt dword ptr [rsp+748h+var_198], 0Eh `4037027F jb loc_1403C8D38 `40370285 `40370285 loc_140370285: `40370285 mov [rsp+748h+var_638], 10000Bh `40370290 mov rax, cs:PspUserThreadStart `40370297 mov [rsp+748h+var_570], rax `4037029F mov rax, [rsp+748h+arg_20] `403702A7 mov [rsp+748h+var_5E8], rax `403702AF mov rax, [rsp+748h+arg_28] `403702B7 mov [rsp+748h+var_5E0], rax `403702BF mov ecx, 2Bh `403702C4 mov [rsp+748h+var_62E], cx `403702CC mov [rsp+748h+var_62C], cx `403702D4 lea eax, [rcx+28h] `403702D7 mov [rsp+748h+var_62A], ax `403702DF mov [rsp+748h+var_628], cx `403702E7 mov [rsp+748h+var_626], cx `403702EF lea eax, [rcx+8] `403702F2 mov [rsp+748h+var_630], ax `403702FA mov ecx, 1F80h `403702FF mov [rsp+748h+var_634], ecx `40370306 mov eax, 27Fh `4037030B mov [rsp+748h+var_568], ax `40370313 mov [rsp+748h+var_550], ecx `4037031A lea rax, [rsp+748h+var_6D8] `4037031F mov [rsp+748h+var_6E0], rax `40370324 and [rsp+748h+var_6E8], 0 `4037032A and [rsp+748h+var_6F0], 0 `40370330 mov dword ptr [rsp+748h+var_6F8], r12d ; __int64 `40370335 lea rax, [rsp+748h+var_6A8] `4037033D mov [rsp+748h+var_700], rax ; __int64 `40370342 lea rax, [rsp+748h+var_668] `4037034A mov [rsp+748h+var_708], rax ; __int64 `4037034F mov rax, qword ptr [rsp+748h+var_190] `40370357 mov qword ptr [rsp+748h+var_710], rax ; int `4037035C mov qword ptr [rsp+748h+var_718], rbx ; int `40370361 lea rax, [rsp+748h+var_198] `40370369 mov [rsp+748h+var_720], rax ; __int64 `4037036E and [rsp+748h+var_728], 0 `40370374 mov r9, r15 ; __int64 `40370377 mov r8, r14 ; __int64 `4037037A mov edx, r13d ; __int64 `4037037D mov rcx, rsi ; PVOID `40370380 call PspCreateThread
上面的反彙編指令片段是在 IDA 中截取的。根據彙編代碼顯示，[rsp+748h+var_6E0] 是傳入 PspCreateThread 函數的第 14 個參數。其取值為 [rsp+748h+var_6D8] 局部變量的地址。var_6D8 是位於棧上的一個結構體對象，需要關注的是其中 +10 偏移的域，在稍早時候對結構體賦初值，這個域由第 9 個參數 [rsp+748h+arg_40] 賦值。
`403701DF mov [rsp+748h+var_6D8], bl `403701E3 mov rax, [rsp+748h+arg_40] `403701EB mov [rsp+748h+var_6C8], rax
由第 9 個參數賦初值，那就說明這個值是由 NtCreateThreadEx 的調用者傳入的。該函數原型如下：
NTSTATUS
NTAPI
Handle_SSDT_NtCreateThreadEx(
OUT PHANDLE ThreadHandle,
IN ACCESS_MASK DesiredAccess,
IN POBJECT_ATTRIBUTES ObjectAttributes,
IN HANDLE ProcessHandle,
IN LPTHREAD_START_ROUTINE StartAddress,
IN LPVOID Parameter,
IN BOOL CreateSuspended,
IN ULONG StackZeroBits,
IN ULONG SizeOfStackCommit,
IN ULONG SizeOfStackReserve,
OUT LPVOID BytesBuffer
);
第 9 個參數是 SizeOfStackCommit，但我在 Hook 處理函數中監控這個參數，它的值始終是處於正常範圍的數值，從未出現前面分析中的 0xFFFFF88000000000 這樣的數據。突然注意到在 Hook 處理函數中調用原函數時對棧上的參數進行賦值的代碼：
`050721af 488b8424d0000000 mov rax,qword ptr [rsp+0D0h] `050721b7 4889442450 mov qword ptr [rsp+50h],rax `050721bc 8b8424c8000000 mov eax,dword ptr [rsp+0C8h] `050721c3 89442448 mov dword ptr [rsp+48h],eax `050721c7 8b8424c0000000 mov eax,dword ptr [rsp+0C0h] `050721ce 89442440 mov dword ptr [rsp+40h],eax `050721d2 8b8424b8000000 mov eax,dword ptr [rsp+0B8h] `050721d9 89442438 mov dword ptr [rsp+38h],eax `050721dd 8b8424b0000000 mov eax,dword ptr [rsp+0B0h] `050721e4 89442430 mov dword ptr [rsp+30h],eax `050721e8 488b8424a8000000 mov rax,qword ptr [rsp+0A8h] `050721f0 4889442428 mov qword ptr [rsp+28h],rax `050721f5 488b8424a0000000 mov rax,qword ptr [rsp+0A0h] `050721fd 4889442420 mov qword ptr [rsp+20h],rax `05072202 4c8b8c2498000000 mov r9,qword ptr [rsp+98h] `0507220a 4c8b842490000000 mov r8,qword ptr [rsp+90h] `05072212 8b942488000000 mov edx,dword ptr [rsp+88h] `05072219 488b8c2480000000 mov rcx,qword ptr [rsp+80h] `05072221 ff542468 call qword ptr [rsp+68h]
上面代碼中 mov dword ptr [rsp+40h], eax 這條指令對 SizeOfStackCommit 參數進行傳值。在傳值之前我無意中看了一下 rsp+40h 地址的原值：
kd> dq [rsp+40h] l1 fffff880`0310ea30 fffff880`0310ea98
原來如此，由於 Hook 處理函數和原函數指針類型定義失誤，將這個參數定義成了 ULONG32 類型，所以在傳參時只通過 eax 進行賦值，棧上的參數位置高 32 位被忽略並保持原值；但在實際的 NtCreateThreadEx 函數中，應是將這個參數作為 ULONG_PTR 進行解析，在 64 位下應是 ULONG64 寬度，所以將參數中沒有清零的高 32 位也作為參數值的一部分了，這就最終導致了前面的錯誤狀態碼。而這次的錯誤和虛擬化無關。
真是一次坑爹的分析。