PEB(Process Environment Block,进程环境块)存放进程信息,每个进程都有自己的PEB信息。位于用户地址空间。
PEB地址可以通过函数PsGetProcessPeb(EPROCESS)来获得,也可以通过EPROCESS基地址加偏移0x1b0(x86)来获得。
PEB结构
typedef struct _PEB { // Size: 0x1D8 /**/ UCHAR InheritedAddressSpace; /**/ UCHAR ReadImageFileExecOptions; /**/ UCHAR BeingDebugged; /**/ UCHAR SpareBool; /**/ HANDLE Mutant; /**/ HINSTANCE ImageBaseAddress; /*00C*/ VOID *DllList; /**/ PPROCESS_PARAMETERS *ProcessParameters; //进程参数块 /**/ ULONG SubSystemData; /**/ HANDLE DefaultHeap; /*01C*/ KSPIN_LOCK FastPebLock; /**/ ULONG FastPebLockRoutine; /**/ ULONG FastPebUnlockRoutine; /**/ ULONG EnvironmentUpdateCount; /*02C*/ ULONG KernelCallbackTable; /**/ LARGE_INTEGER SystemReserved; /**/ ULONG FreeList; /*03C*/ ULONG TlsExpansionCounter; /**/ ULONG TlsBitmap; /**/ LARGE_INTEGER TlsBitmapBits; /*04C*/ ULONG ReadOnlySharedMemoryBase; /**/ ULONG ReadOnlySharedMemoryHeap; /**/ ULONG ReadOnlyStaticServerData; /**/ ULONG AnsiCodePageData; /*05C*/ ULONG OemCodePageData; /**/ ULONG UnicodeCaseTableData; /**/ ULONG NumberOfProcessors; /**/ LARGE_INTEGER NtGlobalFlag; /**/ LARGE_INTEGER CriticalSectionTimeout; /**/ ULONG HeapSegmentReserve; /*07C*/ ULONG HeapSegmentCommit; /**/ ULONG HeapDeCommitTotalFreeThreshold; /**/ ULONG HeapDeCommitFreeBlockThreshold; /**/ ULONG NumberOfHeaps; /*08C*/ ULONG MaximumNumberOfHeaps; /**/ ULONG ProcessHeaps; /**/ ULONG GdiSharedHandleTable; /**/ ULONG ProcessStarterHelper; /*09C*/ ULONG GdiDCAttributeList; /*0A0*/ KSPIN_LOCK LoaderLock; /*0A4*/ ULONG OSMajorVersion; /*0A8*/ ULONG OSMinorVersion; /*0AC*/ USHORT OSBuildNumber; /*0AE*/ USHORT OSCSDVersion; /*0B0*/ ULONG OSPlatformId; /*0B4*/ ULONG ImageSubsystem; /*0B8*/ ULONG ImageSubsystemMajorVersion; /*0BC*/ ULONG ImageSubsystemMinorVersion; /*0C0*/ ULONG ImageProcessAffinityMask; /*0C4*/ ULONG GdiHandleBuffer[0x22]; /*14C*/ ULONG PostProcessInitRoutine; /**/ ULONG TlsExpansionBitmap; /**/ UCHAR TlsExpansionBitmapBits[0x80]; /*1D4*/ ULONG SessionId; } PEB, *PPEB;
PEB偏移0x10处还有个指针ProcessParameters,指向一个进程参数块PPB、即RTL_USER_PROCESS_PARAMETERS数据结构。
这PPB也是在用户空间的,虽然是个独立存在的数据结构,逻辑上却可以看作是PEB的一部分。
进程参数块RTL_USER_PROCESS_PARAMETERS结构
typedef struct _RTL_USER_PROCESS_PARAMETERS
{
ULONG MaximumLength;
ULONG Length;
ULONG Flags;
ULONG DebugFlags;
PVOID ConsoleHandle;
ULONG ConsoleFlags;
PVOID StandardInput;
PVOID StandardOutput;
PVOID StandardError;
CURDIR CurrentDirectory;
UNICODE_STRING DllPath;
UNICODE_STRING ImagePathName; //进程完整路径
UNICODE_STRING CommandLine;
PVOID Environment;
ULONG StartingX;
ULONG StartingY;
ULONG CountX;
ULONG CountY;
ULONG CountCharsX;
ULONG CountCharsY;
ULONG FillAttribute;
ULONG WindowFlags;
ULONG ShowWindowFlags;
UNICODE_STRING WindowTitle;
UNICODE_STRING DesktopInfo;
UNICODE_STRING ShellInfo;
UNICODE_STRING RuntimeData;
RTL_DRIVE_LETTER_CURDIR CurrentDirectores[];
ULONG EnvironmentSize;
} RTL_USER_PROCESS_PARAMETERS, *PRTL_USER_PROCESS_PARAMETERS;
下面以x86为例,在Windbg中可以具体实验感受一下:
1.先随便找个进程
2.注意PEB是在用户空间,从他的地址也可以看出来,因为7ffdf000<80000000,
所以在查看PEB时要先使用命令 .process 899ac958 切入我们我们所找的SogouExe.exe进程的地址空间中,这个很重要
然后我们查看进程SogouExe.exe的PEB
3.在偏移0x10处看到了结构体RTL_USER_PROCESS_PARAMETERS,从图中可以看出,它位于地址0x20000处
继续查看它
4,在偏移0x38处就存放着进程完整路径。OK,成功找到,这样就可以进入具体的代码实现了
BOOLEAN GetProcessPathByEProcess(PEPROCESS EProcess,WCHAR* wzProcessPath)
{
PPEB Peb = NULL;
KAPC_STATE ApcState;
ULONG_PTR ProcessParameters = NULL; if (EProcess==NULL||!MmIsAddressValid(EProcess))
{
return FALSE;
}
Peb = PsGetProcessPeb(EProcess);
if (Peb==NULL)
{
return FALSE;
} KeStackAttachProcess(EProcess, &ApcState); //切入进程地址空间,很重要 ProcessParameters = *(ULONG_PTR*)((ULONG_PTR)Peb+ProcessParametersOfPeb); memcpy(wzProcessPath,((PUNICODE_STRING)((ULONG_PTR)ProcessParameters+ImagePathNameOfProcessParameters))->Buffer,
((PUNICODE_STRING)((ULONG_PTR)ProcessParameters+ImagePathNameOfProcessParameters))->Length); KeUnstackDetachProcess(&ApcState); //切出进程,很重要 return TRUE;
}