404 lines
13 KiB
C#
404 lines
13 KiB
C#
/*
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Copyright (C) 2011-2012 de4dot@gmail.com
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This file is part of de4dot.
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de4dot is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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de4dot is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with de4dot. If not, see <http://www.gnu.org/licenses/>.
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*/
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using System;
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using System.Collections.Generic;
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using Mono.Cecil;
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using Mono.MyStuff;
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using de4dot.blocks;
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using de4dot.blocks.cflow;
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using de4dot.PE;
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namespace de4dot.code.deobfuscators.Confuser {
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public class DeobfuscatorInfo : DeobfuscatorInfoBase {
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public const string THE_NAME = "Confuser";
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public const string THE_TYPE = "cr";
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BoolOption removeAntiDebug;
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BoolOption removeAntiDump;
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public DeobfuscatorInfo()
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: base() {
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removeAntiDebug = new BoolOption(null, makeArgName("antidb"), "Remove anti debug code", true);
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removeAntiDump = new BoolOption(null, makeArgName("antidump"), "Remove anti dump code", true);
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}
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public override string Name {
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get { return THE_NAME; }
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}
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public override string Type {
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get { return THE_TYPE; }
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}
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public override IDeobfuscator createDeobfuscator() {
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return new Deobfuscator(new Deobfuscator.Options {
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ValidNameRegex = validNameRegex.get(),
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RemoveAntiDebug = removeAntiDebug.get(),
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RemoveAntiDump = removeAntiDump.get(),
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});
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}
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protected override IEnumerable<Option> getOptionsInternal() {
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return new List<Option>() {
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removeAntiDebug,
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removeAntiDump,
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};
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}
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}
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class Deobfuscator : DeobfuscatorBase {
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Options options;
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string obfuscatorName = DeobfuscatorInfo.THE_NAME;
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JitMethodsDecrypter jitMethodsDecrypter;
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MemoryMethodsDecrypter memoryMethodsDecrypter;
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ProxyCallFixer proxyCallFixer;
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ProxyCallFixerV1 proxyCallFixerV1;
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AntiDebugger antiDebugger;
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AntiDumping antiDumping;
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ResourceDecrypter resourceDecrypter;
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ConstantsDecrypter constantsDecrypter;
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Int32ValueInliner int32ValueInliner;
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Int64ValueInliner int64ValueInliner;
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SingleValueInliner singleValueInliner;
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DoubleValueInliner doubleValueInliner;
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StringDecrypter stringDecrypter;
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Unpacker unpacker;
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bool startedDeobfuscating = false;
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internal class Options : OptionsBase {
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public bool RemoveAntiDebug { get; set; }
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public bool RemoveAntiDump { get; set; }
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}
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public override string Type {
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get { return DeobfuscatorInfo.THE_TYPE; }
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}
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public override string TypeLong {
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get { return DeobfuscatorInfo.THE_NAME; }
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}
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public override string Name {
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get { return obfuscatorName; }
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}
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public override IEnumerable<IBlocksDeobfuscator> BlocksDeobfuscators {
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get {
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var list = new List<IBlocksDeobfuscator>();
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list.Add(new ConstantsFolder { ExecuteOnNoChange = true });
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// Add this one last so all cflow is deobfuscated whenever it executes
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if (!startedDeobfuscating && int32ValueInliner != null)
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list.Add(new ConstantsInliner(int32ValueInliner, int64ValueInliner, singleValueInliner, doubleValueInliner) { ExecuteOnNoChange = true });
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return list;
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}
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}
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public Deobfuscator(Options options)
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: base(options) {
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this.options = options;
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StringFeatures = StringFeatures.AllowStaticDecryption | StringFeatures.AllowDynamicDecryption;
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}
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protected override int detectInternal() {
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int val = 0;
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int sum = toInt32(jitMethodsDecrypter != null ? jitMethodsDecrypter.Detected : false) +
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toInt32(memoryMethodsDecrypter != null ? memoryMethodsDecrypter.Detected : false) +
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toInt32(proxyCallFixer != null ? proxyCallFixer.Detected : false) +
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toInt32(proxyCallFixerV1 != null ? proxyCallFixerV1.Detected : false) +
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toInt32(antiDebugger != null ? antiDebugger.Detected : false) +
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toInt32(antiDumping != null ? antiDumping.Detected : false) +
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toInt32(resourceDecrypter != null ? resourceDecrypter.Detected : false) +
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toInt32(constantsDecrypter != null ? constantsDecrypter.Detected : false) +
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toInt32(stringDecrypter != null ? stringDecrypter.Detected : false) +
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toInt32(unpacker != null ? unpacker.Detected : false);
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if (sum > 0)
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val += 100 + 10 * (sum - 1);
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return val;
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}
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protected override void scanForObfuscator() {
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jitMethodsDecrypter = new JitMethodsDecrypter(module, DeobfuscatedFile);
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try {
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jitMethodsDecrypter.find();
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}
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catch {
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}
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if (jitMethodsDecrypter.Detected)
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return;
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memoryMethodsDecrypter = new MemoryMethodsDecrypter(module, DeobfuscatedFile);
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memoryMethodsDecrypter.find();
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if (memoryMethodsDecrypter.Detected)
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return;
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initTheRest();
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}
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void initTheRest() {
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resourceDecrypter = new ResourceDecrypter(module, DeobfuscatedFile);
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resourceDecrypter.find();
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constantsDecrypter = new ConstantsDecrypter(module, getFileData(), DeobfuscatedFile);
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constantsDecrypter.find();
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if (constantsDecrypter.Detected)
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initializeConstantsDecrypter();
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proxyCallFixer = new ProxyCallFixer(module, getFileData(), DeobfuscatedFile);
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proxyCallFixer.findDelegateCreator();
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if (!proxyCallFixer.Detected) {
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proxyCallFixerV1 = new ProxyCallFixerV1(module);
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proxyCallFixerV1.findDelegateCreator(DeobfuscatedFile);
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}
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antiDebugger = new AntiDebugger(module);
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antiDebugger.find();
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antiDumping = new AntiDumping(module);
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antiDumping.find(DeobfuscatedFile);
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stringDecrypter = new StringDecrypter(module);
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stringDecrypter.find(DeobfuscatedFile);
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initializeStringDecrypter();
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unpacker = new Unpacker(module);
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unpacker.find(DeobfuscatedFile, this);
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}
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byte[] getFileData() {
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if (ModuleBytes != null)
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return ModuleBytes;
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return ModuleBytes = DeobUtils.readModule(module);
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}
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[Flags]
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enum DecryptState {
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CanDecryptMethods = 1,
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CanUnpack = 2,
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}
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DecryptState decryptState = DecryptState.CanDecryptMethods | DecryptState.CanUnpack;
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public override bool getDecryptedModule(int count, ref byte[] newFileData, ref DumpedMethods dumpedMethods) {
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byte[] fileData = getFileData();
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var peImage = new PeImage(fileData);
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if ((decryptState & DecryptState.CanDecryptMethods) != 0) {
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bool decrypted = false;
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if (jitMethodsDecrypter != null && jitMethodsDecrypter.Detected) {
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jitMethodsDecrypter.initialize();
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if (!jitMethodsDecrypter.decrypt(peImage, fileData, ref dumpedMethods))
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return false;
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decrypted = true;
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}
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else if (memoryMethodsDecrypter != null && memoryMethodsDecrypter.Detected) {
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memoryMethodsDecrypter.initialize();
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if (!memoryMethodsDecrypter.decrypt(peImage, fileData, ref dumpedMethods))
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return false;
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decrypted = true;
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}
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if (decrypted) {
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decryptState &= ~DecryptState.CanDecryptMethods;
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decryptState |= DecryptState.CanUnpack;
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newFileData = fileData;
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ModuleBytes = newFileData;
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return true;
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}
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}
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if ((decryptState & DecryptState.CanUnpack) != 0) {
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if (unpacker != null && unpacker.Detected) {
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decryptState |= DecryptState.CanDecryptMethods | DecryptState.CanUnpack;
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newFileData = unpacker.unpack();
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ModuleBytes = newFileData;
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return true;
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}
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}
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return false;
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}
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public override IDeobfuscator moduleReloaded(ModuleDefinition module) {
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var newOne = new Deobfuscator(options);
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DeobfuscatedFile.setDeobfuscator(newOne);
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newOne.decryptState = decryptState;
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newOne.DeobfuscatedFile = DeobfuscatedFile;
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newOne.ModuleBytes = ModuleBytes;
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newOne.setModule(module);
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newOne.jitMethodsDecrypter = new JitMethodsDecrypter(module, DeobfuscatedFile, jitMethodsDecrypter);
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if ((newOne.decryptState & DecryptState.CanDecryptMethods) != 0) {
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try {
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newOne.jitMethodsDecrypter.find();
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}
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catch {
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}
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if (newOne.jitMethodsDecrypter.Detected)
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return newOne;
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}
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newOne.memoryMethodsDecrypter = new MemoryMethodsDecrypter(module, DeobfuscatedFile, memoryMethodsDecrypter);
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if ((newOne.decryptState & DecryptState.CanDecryptMethods) != 0) {
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newOne.memoryMethodsDecrypter.find();
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if (newOne.memoryMethodsDecrypter.Detected)
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return newOne;
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}
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newOne.initTheRest();
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return newOne;
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}
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public override void deobfuscateBegin() {
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base.deobfuscateBegin();
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removeObfuscatorAttribute();
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initializeConstantsDecrypter();
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initializeStringDecrypter();
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if (jitMethodsDecrypter != null) {
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addModuleCctorInitCallToBeRemoved(jitMethodsDecrypter.InitMethod);
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addTypeToBeRemoved(jitMethodsDecrypter.Type, "Method decrypter (JIT) type");
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}
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if (memoryMethodsDecrypter != null) {
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addModuleCctorInitCallToBeRemoved(memoryMethodsDecrypter.InitMethod);
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addTypeToBeRemoved(memoryMethodsDecrypter.Type, "Method decrypter (memory) type");
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}
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if (options.RemoveAntiDebug) {
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addModuleCctorInitCallToBeRemoved(antiDebugger.InitMethod);
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addTypeToBeRemoved(antiDebugger.Type, "Anti debugger type");
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if (antiDebugger.Type == DotNetUtils.getModuleType(module))
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addMethodToBeRemoved(antiDebugger.InitMethod, "Anti debugger method");
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}
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if (options.RemoveAntiDump) {
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addModuleCctorInitCallToBeRemoved(antiDumping.InitMethod);
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addTypeToBeRemoved(antiDumping.Type, "Anti dumping type");
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}
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if (proxyCallFixer != null)
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proxyCallFixer.find();
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if (proxyCallFixerV1 != null)
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proxyCallFixerV1.find();
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removeInvalidResources();
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startedDeobfuscating = true;
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}
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void removeInvalidResources() {
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foreach (var rsrc in module.Resources) {
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var resource = rsrc as EmbeddedResource;
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if (resource == null)
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continue;
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if (resource.Offset != 0xFFFFFFFF)
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continue;
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addResourceToBeRemoved(resource, "Invalid resource");
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}
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}
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bool hasInitializedStringDecrypter = false;
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void initializeStringDecrypter() {
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if (hasInitializedStringDecrypter)
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return;
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hasInitializedStringDecrypter = true;
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if (stringDecrypter != null && stringDecrypter.Detected) {
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decryptResources();
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stringDecrypter.initialize();
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staticStringInliner.add(stringDecrypter.Method, (method, gim, args) => stringDecrypter.decrypt(staticStringInliner.Method, (int)args[0]));
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}
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}
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bool hasInitializedConstantsDecrypter = false;
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void initializeConstantsDecrypter() {
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if (hasInitializedConstantsDecrypter)
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return;
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hasInitializedConstantsDecrypter = true;
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decryptResources();
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constantsDecrypter.initialize();
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int32ValueInliner = new Int32ValueInliner();
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int64ValueInliner = new Int64ValueInliner();
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singleValueInliner = new SingleValueInliner();
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doubleValueInliner = new DoubleValueInliner();
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foreach (var info in constantsDecrypter.Decrypters) {
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staticStringInliner.add(info.method, (method, gim, args) => constantsDecrypter.decryptString(method, gim, (uint)args[0], (ulong)args[1]));
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int32ValueInliner.add(info.method, (method, gim, args) => constantsDecrypter.decryptInt32(method, gim, (uint)args[0], (ulong)args[1]));
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int64ValueInliner.add(info.method, (method, gim, args) => constantsDecrypter.decryptInt64(method, gim, (uint)args[0], (ulong)args[1]));
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singleValueInliner.add(info.method, (method, gim, args) => constantsDecrypter.decryptSingle(method, gim, (uint)args[0], (ulong)args[1]));
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doubleValueInliner.add(info.method, (method, gim, args) => constantsDecrypter.decryptDouble(method, gim, (uint)args[0], (ulong)args[1]));
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}
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DeobfuscatedFile.stringDecryptersAdded();
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addTypesToBeRemoved(constantsDecrypter.Types, "Constants decrypter type");
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addFieldsToBeRemoved(constantsDecrypter.Fields, "Constants decrypter field");
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addMethodToBeRemoved(constantsDecrypter.NativeMethod, "Constants decrypter native method");
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addResourceToBeRemoved(constantsDecrypter.Resource, "Encrypted constants");
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}
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void decryptResources() {
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var rsrc = resourceDecrypter.mergeResources();
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if (rsrc == null)
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return;
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addResourceToBeRemoved(rsrc, "Encrypted resources");
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addMethodToBeRemoved(resourceDecrypter.Handler, "Resource decrypter handler");
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addFieldsToBeRemoved(resourceDecrypter.Fields, "Resource decrypter field");
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}
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void removeObfuscatorAttribute() {
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foreach (var type in module.Types) {
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if (type.FullName == "ConfusedByAttribute")
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addAttributeToBeRemoved(type, "Obfuscator attribute");
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}
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}
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public override void deobfuscateMethodEnd(Blocks blocks) {
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if (proxyCallFixer != null)
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proxyCallFixer.deobfuscate(blocks);
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if (proxyCallFixerV1 != null)
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proxyCallFixerV1.deobfuscate(blocks);
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resourceDecrypter.deobfuscate(blocks);
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int32ValueInliner.decrypt(blocks);
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int64ValueInliner.decrypt(blocks);
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singleValueInliner.decrypt(blocks);
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doubleValueInliner.decrypt(blocks);
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base.deobfuscateMethodEnd(blocks);
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}
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public override void deobfuscateEnd() {
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if (proxyCallFixer != null)
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removeProxyDelegates(proxyCallFixer);
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if (proxyCallFixerV1 != null) {
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if (removeProxyDelegates(proxyCallFixerV1))
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addFieldsToBeRemoved(proxyCallFixerV1.Fields, "Proxy delegate instance field");
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proxyCallFixerV1.cleanUp();
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}
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constantsDecrypter.cleanUp();
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if (CanRemoveStringDecrypterType) {
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if (stringDecrypter != null) {
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addMethodToBeRemoved(stringDecrypter.Method, "String decrypter method");
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addResourceToBeRemoved(stringDecrypter.Resource, "Encrypted strings");
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}
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}
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base.deobfuscateEnd();
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}
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public override IEnumerable<int> getStringDecrypterMethods() {
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var list = new List<int>();
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return list;
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}
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}
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}
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