Beispiel #1
0
        // Token: 0x06000121 RID: 289 RVA: 0x0000DB90 File Offset: 0x0000BD90
        private static void PatchRelocations(PortableExecutable image, IntPtr pAlloc)
        {
            IMAGE_DATA_DIRECTORY image_DATA_DIRECTORY = image.NTHeader.OptionalHeader.DataDirectory[5];

            if (image_DATA_DIRECTORY.Size > 0u)
            {
                uint num  = 0u;
                uint num2 = (uint)((long)pAlloc.ToInt32() - (long)((ulong)image.NTHeader.OptionalHeader.ImageBase));
                uint num3 = image.GetPtrFromRVA(image_DATA_DIRECTORY.VirtualAddress);
                uint num4 = (uint)Marshal.SizeOf(typeof(IMAGE_BASE_RELOCATION));
                IMAGE_BASE_RELOCATION image_BASE_RELOCATION;
                while (num < image_DATA_DIRECTORY.Size && image.Read <IMAGE_BASE_RELOCATION>((long)((ulong)num3), SeekOrigin.Begin, out image_BASE_RELOCATION))
                {
                    int  num5       = (int)((image_BASE_RELOCATION.SizeOfBlock - num4) / 2u);
                    uint ptrFromRVA = image.GetPtrFromRVA(image_BASE_RELOCATION.VirtualAddress);
                    for (int i = 0; i < num5; i++)
                    {
                        ushort num6;
                        if (image.Read <ushort>((long)((ulong)(num3 + num4) + (ulong)((long)((long)i << 1))), SeekOrigin.Begin, out num6) && (num6 >> 12 & 3) != 0)
                        {
                            uint num7 = (uint)((ulong)ptrFromRVA + (ulong)((long)(num6 & 4095)));
                            uint num8;
                            if (!image.Read <uint>((long)((ulong)num7), SeekOrigin.Begin, out num8))
                            {
                                throw image.GetLastError();
                            }
                            image.Write <uint>(-4L, SeekOrigin.Current, num8 + num2);
                        }
                    }
                    num  += image_BASE_RELOCATION.SizeOfBlock;
                    num3 += image_BASE_RELOCATION.SizeOfBlock;
                }
            }
        }
Beispiel #2
0
        private static void PatchImports(PortableExecutable image, IntPtr hProcess, int processId)
        {
            string empty  = string.Empty;
            string empty2 = string.Empty;

            foreach (IMAGE_IMPORT_DESCRIPTOR current in image.EnumImports())
            {
                if (image.ReadString((long)((ulong)image.GetPtrFromRVA(current.Name)), SeekOrigin.Begin, out empty, -1, null))
                {
                    IntPtr intPtr   = IntPtr.Zero;
                    IntPtr arg_4F_0 = IntPtr.Zero;
                    intPtr = ManualMap.GetRemoteModuleHandle(empty, processId);
                    if (intPtr.IsNull())
                    {
                        throw new FileNotFoundException(string.Format("Unable to load dependent module '{0}'.", empty));
                    }
                    uint             num  = image.GetPtrFromRVA(current.FirstThunkPtr);
                    uint             num2 = (uint)Marshal.SizeOf(typeof(IMAGE_THUNK_DATA));
                    IMAGE_THUNK_DATA iMAGE_THUNK_DATA;
                    while (image.Read <IMAGE_THUNK_DATA>((long)((ulong)num), SeekOrigin.Begin, out iMAGE_THUNK_DATA) && iMAGE_THUNK_DATA.u1.AddressOfData > 0u)
                    {
                        IntPtr intPtr2 = IntPtr.Zero;
                        object obj;
                        if ((iMAGE_THUNK_DATA.u1.Ordinal & 2147483648u) == 0u)
                        {
                            if (!image.ReadString((long)((ulong)(image.GetPtrFromRVA(iMAGE_THUNK_DATA.u1.AddressOfData) + 2u)), SeekOrigin.Begin, out empty2, -1, null))
                            {
                                throw image.GetLastError();
                            }
                            obj = empty2;
                        }
                        else
                        {
                            obj = (ushort)(iMAGE_THUNK_DATA.u1.Ordinal & 65535u);
                        }
                        if (!(intPtr2 = WinAPI.GetModuleHandleA(empty)).IsNull())
                        {
                            IntPtr ptr = obj.GetType().Equals(typeof(string)) ? WinAPI.GetProcAddress(intPtr2, (string)obj) : WinAPI.GetProcAddress(intPtr2, (uint)((ushort)obj & 65535));
                            if (!ptr.IsNull())
                            {
                                intPtr2 = intPtr.Add((long)ptr.Subtract((long)intPtr2.ToInt32()).ToInt32());
                            }
                        }
                        else
                        {
                            intPtr2 = WinAPI.GetProcAddressEx(hProcess, intPtr, obj);
                        }
                        if (intPtr2.IsNull())
                        {
                            throw new EntryPointNotFoundException(string.Format("Unable to locate imported function '{0}' from module '{1}' in the remote process.", empty2, empty));
                        }
                        image.Write <int>((long)((ulong)num), SeekOrigin.Begin, intPtr2.ToInt32());
                        num += num2;
                    }
                }
            }
        }
Beispiel #3
0
        private static void PatchRelocations(PortableExecutable image, IntPtr pAlloc)
        {
            // Base relocations are essentially Microsofts ingenious way of preserving portability in images.
            // for all absolute address calls/jmps/references...etc, an entry is made into the base relocation
            // table telling the loader exactly where an "absolute" address is being used. This allows the loader
            // to iterate through the relocations and patch these absolute values to ensure they are correct when
            // the image is loaded somewhere that isn't its preferred base address.
            IMAGE_DATA_DIRECTORY relocDir = image.NTHeader.OptionalHeader.DataDirectory[(int)DATA_DIRECTORIES.BaseRelocTable];

            if (relocDir.Size > 0) //check if there are in fact any relocations.
            {
                uint n       = 0;
                uint delta   = (uint)(pAlloc.ToInt32() - image.NTHeader.OptionalHeader.ImageBase); //The difference in loaded/preferred addresses.
                uint pReloc  = image.GetPtrFromRVA(relocDir.VirtualAddress);
                uint szReloc = (uint)Marshal.SizeOf(typeof(IMAGE_BASE_RELOCATION));
                IMAGE_BASE_RELOCATION reloc;

                while (n < relocDir.Size && image.Read(pReloc, SeekOrigin.Begin, out reloc))
                {
                    // A relocation block consists of an IMAGE_BASE_RELOCATION, and an array of WORDs.
                    // To calculate the number of relocations (represented by WORDs), just do some simple math.
                    int    nrelocs = (int)((reloc.SizeOfBlock - szReloc) / sizeof(ushort));
                    uint   pageVa  = image.GetPtrFromRVA(reloc.VirtualAddress); //The Page RVA for this set of relocations (usually a 4K boundary).
                    ushort vreloc;
                    uint   old;

                    for (int i = 0; i < nrelocs; i++)
                    {
                        // There are only 2 types of relocations on Intel machines: ABSOLUTE (padding, nothing needs to be done) and HIGHLOW (0x03)
                        // Highlow means that all 32 bits of the "delta" value need to be added to the relocation value.
                        if (image.Read(pReloc + szReloc + (i << 1), SeekOrigin.Begin, out vreloc) && (vreloc >> 12 & 3) != 0)
                        {
                            uint vp = (uint)(pageVa + (vreloc & 0x0FFF));
                            if (image.Read <uint>(vp, SeekOrigin.Begin, out old))
                            {
                                image.Write <uint>(-4, SeekOrigin.Current, (uint)(old + delta));
                            }
                            else
                            {
                                throw image.GetLastError(); //unlikely, but I hate crashing targets because something in the PE was messed up.
                            }
                        }
                    }
                    n      += reloc.SizeOfBlock;
                    pReloc += reloc.SizeOfBlock;
                }
            }
        }
Beispiel #4
0
        private static void PatchImports(PortableExecutable image, IntPtr hProcess, int processId)
        {
            string module = string.Empty;
            string fname  = string.Empty;

            foreach (var desc in image.EnumImports())
            {
                if (image.ReadString(image.GetPtrFromRVA(desc.Name), SeekOrigin.Begin, out module))
                {
                    IntPtr pModule = IntPtr.Zero;
                    IntPtr tModule = IntPtr.Zero;
                    //Thanks to FastLoadDependencies, all dependent modules *should* be loaded into the remote process already.
                    pModule = GetRemoteModuleHandle(module, processId);

                    if (pModule.IsNull())
                    {
                        throw new FileNotFoundException(string.Format("Unable to load dependent module '{0}'.", module));
                    }

                    //now have a supposedly valid module handle remote process, all that remains to be done is patch the info.
                    uint             pThunk  = image.GetPtrFromRVA(desc.FirstThunkPtr); //despite the fact FirstThunk and OriginalFirstThunk are identical within an unmapped PE, only FirstThunk is looked up after mapping.
                    uint             szThunk = (uint)Marshal.SizeOf(typeof(IMAGE_THUNK_DATA));
                    IMAGE_THUNK_DATA thunk;

                    while (image.Read(pThunk, SeekOrigin.Begin, out thunk) && thunk.u1.AddressOfData > 0) //final thunk is signified by a null-filled IMAGE_THUNK_DATA structure.
                    {
                        IntPtr remote  = IntPtr.Zero;
                        object procVal = null;
                        if ((thunk.u1.Ordinal & 0x80000000) == 0)                                                               //import by name
                        {
                            if (image.ReadString(image.GetPtrFromRVA(thunk.u1.AddressOfData) + 2, SeekOrigin.Begin, out fname)) //get the function name.
                            {
                                procVal = fname;
                            }
                            else
                            {
                                throw image.GetLastError(); //error occurred during memory iteration, this is only a safeguard and shouldn't really ever occur, but the universe loves proving me wrong.
                            }
                        }
                        else //import by ordinal.
                        {
                            procVal = (ushort)(thunk.u1.Ordinal & 0xFFFF);
                        }

                        // the following section of code simply aims to reduce overhead. A check is first performed to see if the current module
                        // is loaded in the current process first, if so it simply uses relative addresses to calculate the function address in the remote
                        // process. If the module isn't found in our process, a call to GetProcAddressEx is used to find the remote address. Of course, you
                        // could simply guarantee the first case by calling LoadLibrary internally, but I find that can have unwanted side effects.
                        if (!(remote = WinAPI.GetModuleHandleA(module)).IsNull())
                        {
                            IntPtr local = procVal.GetType().Equals(typeof(string))
                                            ? WinAPI.GetProcAddress(remote, (string)procVal)
                                            : WinAPI.GetProcAddress(remote, (uint)((ushort)procVal) & 0x0000FFFF);
                            if (!local.IsNull())
                            {
                                remote = pModule.Add(local.Subtract(remote.ToInt32()).ToInt32());
                            }
                        }
                        else
                        {
                            remote = WinAPI.GetProcAddressEx(hProcess, pModule, procVal);
                        }

                        if (remote.IsNull()) //alas, couldn't find the function.
                        {
                            throw new EntryPointNotFoundException(string.Format("Unable to locate imported function '{0}' from module '{1}' in the remote process.", fname, module));
                        }

                        image.Write <int>(pThunk, SeekOrigin.Begin, remote.ToInt32()); //overwrite the thunk and continue on our merry way.
                        pThunk += szThunk;
                    }
                }
            }
        }