восстановление SSDT

//SSDT Hook Detector
//By xWeasel - April 2007
//Finds SSDT hooks by looping through the system service descriptor table
//if syscall address is outside of the kernel's address space, then it's a hooked function

#include <ntddk.h>
#include "ntifs_6001.h"



typedef struct _MODULE_INFO {
    ULONG dwReserved[2];
    ULONG dwBase;
    ULONG dwSize;
    ULONG dwFlags;
    USHORT wIndex;
    USHORT wRank;
    USHORT wLoadCount;
    USHORT NameOffset;
    char cPath[256];
} MODULE_INFO, *PMODULE_INFO, **PPMODULE_INFO;

typedef struct _MODULE_LIST {
    ULONG dwModules;
    MODULE_INFO Modules[1];
} MODULE_LIST, *PMODULE_LIST, **PPMODULE_LIST;

VOID EnumSSDTEntries(ULONG ulKernelBase, ULONG ulKernelEnd);
PMODULE_LIST GetModuleList();

//Driver entry point
NTSTATUS DriverEntry(IN PDRIVER_OBJECT theDriverObject, IN PUNICODE_STRING theRegistryPath){
    NTSTATUS ntStatus;
    ULONG ulKernelBase, ulKernelEnd;
    PMODULE_LIST pModules = NULL;
    PMODULE_INFO pKernelInfo;

    pModules = GetModuleList();
    if(pModules != NULL){
        pKernelInfo = &pModules->Modules[0];
        ulKernelBase = pKernelInfo->dwBase;
        ulKernelEnd = pKernelInfo->dwBase + pKernelInfo->dwSize;
        EnumSSDTEntries(ulKernelBase, ulKernelEnd);
        ExFreePoolWithTag(pModules, 'mlst');
    }else{
        DbgPrint("Failed to get module list! Exiting...\n");
    }
   
    return STATUS_SUCCESS;
}

//Loop through SSDT entries and check if any system calls aren't within ntoskrnl's range (base and base+size)
VOID EnumSSDTEntries(ULONG ulKernelBase, ULONG ulKernelEnd){
    ULONG ulServiceIndex;
    DbgPrint("Number of services in SSDT: %u\n", (ULONG)KeServiceDescriptorTable->TableSize);
    for(ulServiceIndex = 0; ulServiceIndex < KeServiceDescriptorTable->TableSize; ulServiceIndex++){
        DbgPrint("Syscall #%d is located at %08lX.\n", ulServiceIndex, KeServiceDescriptorTable->ServiceTable[ulServiceIndex]);
        if((ULONG)KeServiceDescriptorTable->ServiceTable[ulServiceIndex] < ulKernelBase || (ULONG)KeServiceDescriptorTable->ServiceTable[ulServiceIndex] > ulKernelEnd){
            DbgPrint("  Syscall #%d at %08lX is hooked!!\n", ulServiceIndex, KeServiceDescriptorTable->ServiceTable[ulServiceIndex]);
        }
    }
}

//List loaded modules (we only need the first one, which is the kernel)
PMODULE_LIST GetModuleList(){
    NTSTATUS NtStatus;
    ULONG ulNeededSize;
    PULONG pulModuleList;

    ZwQuerySystemInformation(SystemModuleInformation, &ulNeededSize, 0, &ulNeededSize);
    pulModuleList = ExAllocatePoolWithTag(PagedPool, ulNeededSize, 'mlst');
    NtStatus = ZwQuerySystemInformation(SystemModuleInformation, pulModuleList, ulNeededSize, 0);

    if(!NT_SUCCESS(NtStatus)){
        DbgPrint("ZwQuerySystemInformation failed! ulNeededSize = %ul, NtStatus = %u.\n", ulNeededSize, NtStatus);
    }
   
    return (PMODULE_LIST) pulModuleList;
}