static void patchDwords(MyPEImage peImage, IBinaryReader reader, int count) { for (int i = 0; i < count; i++) { uint rva = reader.ReadUInt32(); uint data = reader.ReadUInt32(); peImage.dotNetSafeWrite(rva, BitConverter.GetBytes(data)); } }
bool patch2(MyPEImage peImage) { uint numPatches = peImage.offsetReadUInt32(peImage.Length - 4); uint offset = checked (peImage.Length - 4 - numPatches * 8); bool startedPatchingBadData = false; for (uint i = 0; i < numPatches; i++, offset += 8) { uint rva = getValue(peImage.offsetReadUInt32(offset)); var value = peImage.offsetReadUInt32(offset + 4); if (value == 4) { i++; offset += 8; rva = getValue(peImage.offsetReadUInt32(offset)); value = peImage.offsetReadUInt32(offset + 4); } else { value = getValue(value); } // Seems there's a bug in their code where they sometimes overwrite valid data // with invalid data. if (startedPatchingBadData && value == 0x3115) { continue; } startedPatchingBadData |= !peImage.dotNetSafeWrite(rva, BitConverter.GetBytes(value)); } return(true); }
public bool decrypt(MyPEImage peImage, ISimpleDeobfuscator simpleDeobfuscator, ref DumpedMethods dumpedMethods, Dictionary<uint, byte[]> tokenToNativeCode, bool unpackedNativeFile) { if (encryptedResource.Method == null) return false; encryptedResource.init(simpleDeobfuscator); if (!encryptedResource.FoundResource) return false; var methodsData = encryptedResource.decrypt(); bool hooksJitter = findDnrCompileMethod(encryptedResource.Method.DeclaringType) != null; xorKey = getXorKey(); xorEncrypt(methodsData); var methodsDataReader = MemoryImageStream.Create(methodsData); int patchCount = methodsDataReader.ReadInt32(); int mode = methodsDataReader.ReadInt32(); int tmp = methodsDataReader.ReadInt32(); methodsDataReader.Position -= 4; if ((tmp & 0xFF000000) == 0x06000000) { // It's method token + rva. DNR 3.7.0.3 (and earlier?) - 3.9.0.1 methodsDataReader.Position += 8L * patchCount; patchCount = methodsDataReader.ReadInt32(); mode = methodsDataReader.ReadInt32(); patchDwords(peImage, methodsDataReader, patchCount); while (methodsDataReader.Position < methodsData.Length - 1) { uint token = methodsDataReader.ReadUInt32(); int numDwords = methodsDataReader.ReadInt32(); patchDwords(peImage, methodsDataReader, numDwords / 2); } } else if (!hooksJitter || mode == 1) { // DNR 3.9.8.0, 4.0, 4.1, 4.2, 4.3, 4.4 // If it's .NET 1.x, then offsets are used, not RVAs. bool useOffsets = unpackedNativeFile && module.IsClr1x; patchDwords(peImage, methodsDataReader, patchCount); while (methodsDataReader.Position < methodsData.Length - 1) { uint rva = methodsDataReader.ReadUInt32(); uint token = methodsDataReader.ReadUInt32(); // token, unknown, or index int size = methodsDataReader.ReadInt32(); if (size > 0) { var newData = methodsDataReader.ReadBytes(size); if (useOffsets) peImage.dotNetSafeWriteOffset(rva, newData); else peImage.dotNetSafeWrite(rva, newData); } } } else { // DNR 4.0 - 4.5 (jitter is hooked) var methodDef = peImage.DotNetFile.MetaData.TablesStream.MethodTable; var rvaToIndex = new Dictionary<uint, int>((int)methodDef.Rows); uint offset = (uint)methodDef.StartOffset; for (int i = 0; i < methodDef.Rows; i++) { uint rva = peImage.offsetReadUInt32(offset); offset += methodDef.RowSize; if (rva == 0) continue; if ((peImage.readByte(rva) & 3) == 2) rva++; else rva += (uint)(4 * (peImage.readByte(rva + 1) >> 4)); rvaToIndex[rva] = i; } patchDwords(peImage, methodsDataReader, patchCount); int count = methodsDataReader.ReadInt32(); dumpedMethods = new DumpedMethods(); while (methodsDataReader.Position < methodsData.Length - 1) { uint rva = methodsDataReader.ReadUInt32(); uint index = methodsDataReader.ReadUInt32(); bool isNativeCode = index >= 0x70000000; int size = methodsDataReader.ReadInt32(); var methodData = methodsDataReader.ReadBytes(size); int methodIndex; if (!rvaToIndex.TryGetValue(rva, out methodIndex)) { Logger.w("Could not find method having code RVA {0:X8}", rva); continue; } uint methodToken = 0x06000001 + (uint)methodIndex; if (isNativeCode) { totalEncryptedNativeMethods++; if (tokenToNativeCode != null) tokenToNativeCode[methodToken] = methodData; // Convert return true / false methods. The others are converted to // throw 0xDEADCODE. if (DeobUtils.isCode(nativeLdci4, methodData)) { uint val = BitConverter.ToUInt32(methodData, 4); // ldc.i4 XXXXXXXXh / ret methodData = new byte[] { 0x20, 0, 0, 0, 0, 0x2A }; methodData[1] = (byte)val; methodData[2] = (byte)(val >> 8); methodData[3] = (byte)(val >> 16); methodData[4] = (byte)(val >> 24); } else if (DeobUtils.isCode(nativeLdci4_0, methodData)) { // ldc.i4.0 / ret methodData = new byte[] { 0x16, 0x2A }; } else { tokenToNativeMethod[methodToken] = methodData; // ldc.i4 0xDEADCODE / conv.u4 / throw methodData = new byte[] { 0x20, 0xDE, 0xC0, 0xAD, 0xDE, 0x6D, 0x7A }; } } var dm = new DumpedMethod(); peImage.readMethodTableRowTo(dm, MDToken.ToRID(methodToken)); dm.code = methodData; var codeReader = peImage.Reader; codeReader.Position = peImage.rvaToOffset(dm.mdRVA); byte[] code; var mbHeader = MethodBodyParser.parseMethodBody(codeReader, out code, out dm.extraSections); peImage.updateMethodHeaderInfo(dm, mbHeader); dumpedMethods.add(dm); } } return true; }