Decrypt Confuser 1.9 encrypted JIT methods
This commit is contained in:
de4dot
parent
1a1ccb2121
commit
70bd973cdd
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@ -67,6 +67,9 @@
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<Compile Include="deobfuscators\Babel_NET\MemberReferenceConverter.cs" />
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<Compile Include="deobfuscators\Babel_NET\MethodBodyReader.cs" />
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<Compile Include="deobfuscators\Babel_NET\MethodReferenceReader.cs" />
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<Compile Include="deobfuscators\Confuser\ConstantsFolder.cs" />
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<Compile Include="deobfuscators\Confuser\Deobfuscator.cs" />
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<Compile Include="deobfuscators\Confuser\JitMethodsDecrypter.cs" />
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<Compile Include="deobfuscators\dotNET_Reactor\v4\ProxyCallFixer.cs" />
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<Compile Include="deobfuscators\ILProtector\MethodReader.cs" />
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<Compile Include="deobfuscators\ILProtector\MethodsDecrypter.cs" />
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68
de4dot.code/deobfuscators/Confuser/ConstantsFolder.cs
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68
de4dot.code/deobfuscators/Confuser/ConstantsFolder.cs
Normal file
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@ -0,0 +1,68 @@
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/*
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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.Collections.Generic;
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using Mono.Cecil.Cil;
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using de4dot.blocks;
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using de4dot.blocks.cflow;
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namespace de4dot.code.deobfuscators.Confuser {
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class ConstantsFolder : BlockDeobfuscator {
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protected override bool deobfuscate(Block block) {
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bool modified = false;
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var instrs = block.Instructions;
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var constantsReader = createConstantsReader(instrs);
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for (int i = 0; i < instrs.Count; i++) {
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int index = 0;
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Instruction newInstr = null;
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var instr = instrs[i];
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if (constantsReader.isLoadConstant32(instr.Instruction)) {
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index = i;
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int val;
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if (!constantsReader.getInt32(ref index, out val))
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continue;
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newInstr = DotNetUtils.createLdci4(val);
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}
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else if (constantsReader.isLoadConstant64(instr.Instruction)) {
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index = i;
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long val;
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if (!constantsReader.getInt64(ref index, out val))
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continue;
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newInstr = Instruction.Create(OpCodes.Ldc_I8, val);
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}
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if (newInstr == null || index - i <= 1)
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continue;
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block.insert(index++, Instruction.Create(OpCodes.Pop));
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block.insert(index++, newInstr);
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i = index - 1;
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constantsReader = createConstantsReader(instrs);
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modified = true;
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}
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return modified;
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}
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static ConstantsReader createConstantsReader(IList<Instr> instrs) {
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return new ConstantsReader(instrs, false);
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}
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}
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}
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141
de4dot.code/deobfuscators/Confuser/Deobfuscator.cs
Normal file
141
de4dot.code/deobfuscators/Confuser/Deobfuscator.cs
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@ -0,0 +1,141 @@
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/*
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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 = "cn";
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public DeobfuscatorInfo()
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: base() {
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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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});
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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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};
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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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internal class Options : OptionsBase {
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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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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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}
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protected override int detectInternal() {
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int val = 0;
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int sum = toInt32(jitMethodsDecrypter.Detected);
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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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jitMethodsDecrypter.find();
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}
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public override bool getDecryptedModule(int count, ref byte[] newFileData, ref DumpedMethods dumpedMethods) {
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if (count != 0 || !jitMethodsDecrypter.Detected)
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return false;
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byte[] fileData = ModuleBytes ?? DeobUtils.readModule(module);
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var peImage = new PeImage(fileData);
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if (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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newFileData = fileData;
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return true;
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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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newOne.setModule(module);
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newOne.jitMethodsDecrypter = new JitMethodsDecrypter(module, jitMethodsDecrypter);
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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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}
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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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792
de4dot.code/deobfuscators/Confuser/JitMethodsDecrypter.cs
Normal file
792
de4dot.code/deobfuscators/Confuser/JitMethodsDecrypter.cs
Normal file
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@ -0,0 +1,792 @@
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/*
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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 System.IO;
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using System.Security.Cryptography;
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using System.Text;
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using Mono.Cecil;
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using Mono.Cecil.Cil;
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using Mono.Cecil.Metadata;
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using Mono.MyStuff;
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using de4dot.blocks;
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using de4dot.PE;
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namespace de4dot.code.deobfuscators.Confuser {
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class JitMethodsDecrypter : IStringDecrypter {
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ModuleDefinition module;
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ISimpleDeobfuscator simpleDeobfuscator;
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MethodDefinition initMethod;
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MethodDefinition compileMethod;
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MethodDefinition hookConstructStr;
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MethodDefinition decryptMethod;
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ulong lkey0;
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uint key0, key1, key2, key3, key4, key5, key6;
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MethodDataIndexes methodDataIndexes;
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byte[] methodsData;
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struct MethodDataIndexes {
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public int codeSize;
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public int maxStack;
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public int ehs;
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public int localVarSigTok;
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public int options;
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}
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public bool Detected {
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get { return initMethod != null; }
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}
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public JitMethodsDecrypter(ModuleDefinition module, ISimpleDeobfuscator simpleDeobfuscator) {
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this.module = module;
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this.simpleDeobfuscator = simpleDeobfuscator;
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}
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public JitMethodsDecrypter(ModuleDefinition module, JitMethodsDecrypter other) {
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this.module = module;
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this.initMethod = lookup(other.initMethod, "Could not find initMethod");
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}
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T lookup<T>(T def, string errorMessage) where T : MemberReference {
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return DeobUtils.lookup(module, def, errorMessage);
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}
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public void find() {
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find(DotNetUtils.getModuleTypeCctor(module));
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}
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bool find(MethodDefinition method) {
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if (method == null || method.Body == null)
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return false;
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foreach (var instr in method.Body.Instructions) {
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if (instr.OpCode.Code != Code.Call)
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continue;
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var calledMethod = instr.Operand as MethodDefinition;
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if (calledMethod == null || calledMethod.Body == null)
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continue;
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if (!DotNetUtils.isMethod(calledMethod, "System.Void", "()"))
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continue;
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if (!checkType(calledMethod.DeclaringType))
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continue;
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initMethod = calledMethod;
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return true;
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}
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return false;
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}
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bool checkType(TypeDefinition type) {
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if (type == null)
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return false;
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if (type.NestedTypes.Count != 27)
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return false;
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compileMethod = findCompileMethod(type);
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if (compileMethod == null)
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return false;
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hookConstructStr = findHookConstructStr(type);
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if (hookConstructStr == null)
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return false;
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decryptMethod = findDecrypt(type);
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if (decryptMethod == null)
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return false;
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return true;
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}
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static MethodDefinition findCompileMethod(TypeDefinition type) {
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foreach (var method in type.Methods) {
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if (!method.IsStatic || method.Body == null)
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continue;
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if (method.Parameters.Count != 6)
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continue;
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if (method.MethodReturnType.ReturnType.EType != ElementType.U4)
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continue;
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if (method.Parameters[0].ParameterType.EType != ElementType.I)
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continue;
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if (method.Parameters[3].ParameterType.EType != ElementType.U4)
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continue;
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if (method.Parameters[4].ParameterType.FullName != "System.Byte**")
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continue;
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if (method.Parameters[5].ParameterType.FullName != "System.UInt32*")
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continue;
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return method;
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}
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return null;
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}
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static MethodDefinition findHookConstructStr(TypeDefinition type) {
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foreach (var nested in type.NestedTypes) {
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if (nested.Fields.Count != 10)
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continue;
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foreach (var method in nested.Methods) {
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if (method.IsStatic || method.Body == null)
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continue;
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if (method.Parameters.Count != 4)
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continue;
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if (method.Parameters[0].ParameterType.EType != ElementType.I)
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continue;
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if (method.Parameters[1].ParameterType.EType != ElementType.I)
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continue;
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if (method.Parameters[2].ParameterType.EType != ElementType.U4)
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continue;
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if (method.Parameters[3].ParameterType.FullName != "System.IntPtr&")
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continue;
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return method;
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}
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}
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return null;
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}
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static MethodDefinition findDecrypt(TypeDefinition type) {
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foreach (var method in type.Methods) {
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if (!method.IsStatic || method.Body == null)
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continue;
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if (!DotNetUtils.isMethod(method, "System.Byte[]", "(System.Byte[],System.Byte[],System.Byte[])"))
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continue;
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return method;
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}
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return null;
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||||
}
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public void initialize() {
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if (initMethod == null)
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return;
|
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if (!initializeKeys())
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throw new ApplicationException("Could not find all decryption keys");
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if (!initializeMethodDataIndexes(compileMethod))
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throw new ApplicationException("Could not find MethodData indexes");
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}
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bool initializeKeys() {
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simpleDeobfuscator.deobfuscate(initMethod);
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if (!findLKey0(initMethod, out lkey0))
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return false;
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if (!findKey0(initMethod, out key0))
|
||||
return false;
|
||||
if (!findKey1(initMethod, out key1))
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||||
return false;
|
||||
if (!findKey2Key3(initMethod, out key2, out key3))
|
||||
return false;
|
||||
|
||||
simpleDeobfuscator.deobfuscate(compileMethod);
|
||||
if (!findKey4(compileMethod, out key4))
|
||||
return false;
|
||||
|
||||
simpleDeobfuscator.deobfuscate(hookConstructStr);
|
||||
if (!findKey5(hookConstructStr, out key5))
|
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return false;
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||||
|
||||
simpleDeobfuscator.deobfuscate(decryptMethod);
|
||||
if (!findKey6(decryptMethod, out key6))
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||||
return false;
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||||
|
||||
return true;
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||||
}
|
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|
||||
static bool findLKey0(MethodDefinition method, out ulong key) {
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||||
var instrs = method.Body.Instructions;
|
||||
for (int index = 0; index < instrs.Count; index++) {
|
||||
index = findCallvirtReadUInt64(instrs, index);
|
||||
if (index < 0)
|
||||
break;
|
||||
if (index + 1 >= instrs.Count)
|
||||
continue;
|
||||
var ldci8 = instrs[index + 1];
|
||||
if (ldci8.OpCode.Code != Code.Ldc_I8)
|
||||
continue;
|
||||
|
||||
key = (ulong)(long)ldci8.Operand;
|
||||
return true;
|
||||
}
|
||||
|
||||
key = 0;
|
||||
return false;
|
||||
}
|
||||
|
||||
static bool findKey0(MethodDefinition method, out uint key) {
|
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var instrs = method.Body.Instructions;
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||||
for (int i = 0; i + 5 < instrs.Count; i++) {
|
||||
i = findCallvirtReadUInt32(instrs, i);
|
||||
if (i < 0)
|
||||
break;
|
||||
|
||||
int index = i + 1;
|
||||
var ldci4_1 = instrs[index++];
|
||||
if (!DotNetUtils.isLdcI4(ldci4_1))
|
||||
continue;
|
||||
if (instrs[index++].OpCode.Code != Code.Xor)
|
||||
continue;
|
||||
if (!DotNetUtils.isStloc(instrs[index++]))
|
||||
continue;
|
||||
if (!DotNetUtils.isLdloc(instrs[index++]))
|
||||
continue;
|
||||
var ldci4_2 = instrs[index++];
|
||||
if (!DotNetUtils.isLdcI4(ldci4_2))
|
||||
continue;
|
||||
if (DotNetUtils.getLdcI4Value(ldci4_1) != DotNetUtils.getLdcI4Value(ldci4_2))
|
||||
continue;
|
||||
|
||||
key = (uint)DotNetUtils.getLdcI4Value(ldci4_1);
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||||
return true;
|
||||
}
|
||||
|
||||
key = 0;
|
||||
return false;
|
||||
}
|
||||
|
||||
static bool findKey1(MethodDefinition method, out uint key) {
|
||||
var instrs = method.Body.Instructions;
|
||||
for (int index = 0; index < instrs.Count; index++) {
|
||||
index = findCallvirtReadUInt32(instrs, index);
|
||||
if (index < 0)
|
||||
break;
|
||||
if (index == 0)
|
||||
continue;
|
||||
int i = index - 1;
|
||||
if (!checkCallvirtReadUInt32(instrs, ref i))
|
||||
continue;
|
||||
if (!checkCallvirtReadUInt32(instrs, ref i))
|
||||
continue;
|
||||
if (!checkCallvirtReadUInt32(instrs, ref i))
|
||||
continue;
|
||||
if (!checkCallvirtReadUInt32(instrs, ref i))
|
||||
continue;
|
||||
|
||||
if (i + 1 >= instrs.Count)
|
||||
continue;
|
||||
if (!DotNetUtils.isLdloc(instrs[i]))
|
||||
continue;
|
||||
var ldci4 = instrs[i + 1];
|
||||
if (!DotNetUtils.isLdcI4(ldci4))
|
||||
continue;
|
||||
|
||||
key = (uint)DotNetUtils.getLdcI4Value(ldci4);
|
||||
return true;
|
||||
}
|
||||
|
||||
key = 0;
|
||||
return false;
|
||||
}
|
||||
|
||||
static bool findKey2Key3(MethodDefinition method, out uint key2, out uint key3) {
|
||||
var instrs = method.Body.Instructions;
|
||||
for (int i = 0; i < instrs.Count; i++) {
|
||||
int index = i;
|
||||
if (!findKey2OrKey3(instrs, ref index, out key2))
|
||||
continue;
|
||||
if (!findKey2OrKey3(instrs, ref index, out key3))
|
||||
continue;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
key2 = 0;
|
||||
key3 = 0;
|
||||
return false;
|
||||
}
|
||||
|
||||
static bool findKey2OrKey3(IList<Instruction> instrs, ref int index, out uint key) {
|
||||
key = 0;
|
||||
if (index + 6 >= instrs.Count)
|
||||
return false;
|
||||
int i = index;
|
||||
if (!DotNetUtils.isLdloc(instrs[i++]))
|
||||
return false;
|
||||
if (!DotNetUtils.isLdloc(instrs[i++]))
|
||||
return false;
|
||||
if (!isCallMethod(instrs[i++], Code.Callvirt, "System.Int32 System.IO.BinaryReader::ReadInt32()"))
|
||||
return false;
|
||||
var ldci4 = instrs[i++];
|
||||
if (!DotNetUtils.isLdcI4(ldci4))
|
||||
return false;
|
||||
if (instrs[i++].OpCode.Code != Code.Xor)
|
||||
return false;
|
||||
if (!isCallMethod(instrs[i++], Code.Callvirt, "System.Byte[] System.IO.BinaryReader::ReadBytes(System.Int32)"))
|
||||
return false;
|
||||
if (!DotNetUtils.isStloc(instrs[i++]))
|
||||
return false;
|
||||
|
||||
key = (uint)DotNetUtils.getLdcI4Value(ldci4);
|
||||
index = i;
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool findKey4(MethodDefinition method, out uint key) {
|
||||
var instrs = method.Body.Instructions;
|
||||
for (int index = 0; index < instrs.Count; index++) {
|
||||
index = findCallMethod(instrs, index, Code.Call, "System.Void System.Runtime.InteropServices.Marshal::Copy(System.Byte[],System.Int32,System.IntPtr,System.Int32)");
|
||||
if (index < 0)
|
||||
break;
|
||||
if (index + 2 >= instrs.Count)
|
||||
continue;
|
||||
if (!DotNetUtils.isLdloc(instrs[index + 1]))
|
||||
continue;
|
||||
var ldci4 = instrs[index + 2];
|
||||
if (!DotNetUtils.isLdcI4(ldci4))
|
||||
continue;
|
||||
|
||||
key = (uint)DotNetUtils.getLdcI4Value(ldci4);
|
||||
return true;
|
||||
}
|
||||
|
||||
key = 0;
|
||||
return false;
|
||||
}
|
||||
|
||||
static bool findKey5(MethodDefinition method, out uint key) {
|
||||
var instrs = method.Body.Instructions;
|
||||
for (int i = 0; i + 4 < instrs.Count; i++) {
|
||||
int index = i;
|
||||
var ldci4_8 = instrs[index++];
|
||||
if (!DotNetUtils.isLdcI4(ldci4_8) || DotNetUtils.getLdcI4Value(ldci4_8) != 8)
|
||||
continue;
|
||||
if (instrs[index++].OpCode.Code != Code.Shl)
|
||||
continue;
|
||||
if (instrs[index++].OpCode.Code != Code.Or)
|
||||
continue;
|
||||
var ldci4 = instrs[index++];
|
||||
if (!DotNetUtils.isLdcI4(ldci4))
|
||||
continue;
|
||||
if (instrs[index++].OpCode.Code != Code.Xor)
|
||||
continue;
|
||||
|
||||
key = (uint)DotNetUtils.getLdcI4Value(ldci4);
|
||||
return true;
|
||||
}
|
||||
|
||||
key = 0;
|
||||
return false;
|
||||
}
|
||||
|
||||
static bool findKey6(MethodDefinition method, out uint key) {
|
||||
var instrs = method.Body.Instructions;
|
||||
for (int i = 0; i + 4 < instrs.Count; i++) {
|
||||
int index = i;
|
||||
if (!DotNetUtils.isLdloc(instrs[index++]))
|
||||
continue;
|
||||
if (instrs[index++].OpCode.Code != Code.Sub)
|
||||
continue;
|
||||
if (instrs[index++].OpCode.Code != Code.Ldelem_U1)
|
||||
continue;
|
||||
var ldci4 = instrs[index++];
|
||||
if (!DotNetUtils.isLdcI4(ldci4))
|
||||
continue;
|
||||
if (instrs[index++].OpCode.Code != Code.Xor)
|
||||
continue;
|
||||
if (instrs[index++].OpCode.Code != Code.Conv_U1)
|
||||
continue;
|
||||
|
||||
key = (uint)DotNetUtils.getLdcI4Value(ldci4);
|
||||
return true;
|
||||
}
|
||||
|
||||
key = 0;
|
||||
return false;
|
||||
}
|
||||
|
||||
static bool checkCallvirtReadUInt32(IList<Instruction> instrs, ref int index) {
|
||||
if (index + 2 >= instrs.Count)
|
||||
return false;
|
||||
|
||||
if (!DotNetUtils.isLdloc(instrs[index]))
|
||||
return false;
|
||||
if (!isCallMethod(instrs[index + 1], Code.Callvirt, "System.UInt32 System.IO.BinaryReader::ReadUInt32()"))
|
||||
return false;
|
||||
if (!DotNetUtils.isStloc(instrs[index + 2]))
|
||||
return false;
|
||||
|
||||
index += 3;
|
||||
return true;
|
||||
}
|
||||
|
||||
static int findCallvirtReadUInt32(IList<Instruction> instrs, int index) {
|
||||
return findCallMethod(instrs, index, Code.Callvirt, "System.UInt32 System.IO.BinaryReader::ReadUInt32()");
|
||||
}
|
||||
|
||||
static int findCallvirtReadUInt64(IList<Instruction> instrs, int index) {
|
||||
return findCallMethod(instrs, index, Code.Callvirt, "System.UInt64 System.IO.BinaryReader::ReadUInt64()");
|
||||
}
|
||||
|
||||
static int findCallMethod(IList<Instruction> instrs, int index, Code callCode, string methodFullName) {
|
||||
for (int i = index; i < instrs.Count; i++) {
|
||||
if (!isCallMethod(instrs[i], callCode, methodFullName))
|
||||
continue;
|
||||
|
||||
return i;
|
||||
}
|
||||
return -1;
|
||||
}
|
||||
|
||||
static bool isCallMethod(Instruction instr, Code callCode, string methodFullName) {
|
||||
if (instr.OpCode.Code != callCode)
|
||||
return false;
|
||||
var calledMethod = instr.Operand as MethodReference;
|
||||
return calledMethod != null && calledMethod.FullName == methodFullName;
|
||||
}
|
||||
|
||||
bool initializeMethodDataIndexes(MethodDefinition method) {
|
||||
var methodDataType = findFirstThreeIndexes(method, out methodDataIndexes.maxStack, out methodDataIndexes.ehs, out methodDataIndexes.options);
|
||||
if (methodDataType == null)
|
||||
return false;
|
||||
|
||||
if (!findLocalVarSigTokIndex(method, methodDataType, out methodDataIndexes.localVarSigTok))
|
||||
return false;
|
||||
|
||||
if (!findCodeSizeIndex(method, methodDataType, out methodDataIndexes.codeSize))
|
||||
return false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
static TypeDefinition findFirstThreeIndexes(MethodDefinition method, out int maxStackIndex, out int ehsIndex, out int optionsIndex) {
|
||||
var instrs = method.Body.Instructions;
|
||||
for (int i = 0; i < instrs.Count; i++) {
|
||||
int index1 = findLdfldStind(instrs, i, false, true);
|
||||
if (index1 < 0)
|
||||
break;
|
||||
i = index1;
|
||||
|
||||
int index2 = findLdfldStind(instrs, index1 + 1, true, true);
|
||||
if (index2 < 0)
|
||||
continue;
|
||||
|
||||
int index3 = findLdfldStind(instrs, index2 + 1, true, false);
|
||||
if (index3 < 0)
|
||||
continue;
|
||||
|
||||
var field1 = (FieldDefinition)instrs[index1].Operand;
|
||||
var field2 = (FieldDefinition)instrs[index2].Operand;
|
||||
var field3 = (FieldDefinition)instrs[index3].Operand;
|
||||
if (field1.DeclaringType != field2.DeclaringType || field1.DeclaringType != field3.DeclaringType)
|
||||
continue;
|
||||
maxStackIndex = getInstanceFieldIndex(field1);
|
||||
ehsIndex = getInstanceFieldIndex(field2);
|
||||
optionsIndex = getInstanceFieldIndex(field3);
|
||||
return field1.DeclaringType;
|
||||
}
|
||||
|
||||
maxStackIndex = -1;
|
||||
ehsIndex = -1;
|
||||
optionsIndex = -1;
|
||||
return null;
|
||||
}
|
||||
|
||||
static bool findLocalVarSigTokIndex(MethodDefinition method, TypeDefinition methodDataType, out int localVarSigTokIndex) {
|
||||
var instrs = method.Body.Instructions;
|
||||
for (int i = 0; i < instrs.Count - 1; i++) {
|
||||
var ldfld = instrs[i];
|
||||
if (ldfld.OpCode.Code != Code.Ldfld)
|
||||
continue;
|
||||
var field = ldfld.Operand as FieldDefinition;
|
||||
if (field == null || field.DeclaringType != methodDataType)
|
||||
continue;
|
||||
|
||||
var call = instrs[i + 1];
|
||||
if (call.OpCode.Code != Code.Call)
|
||||
continue;
|
||||
var calledMethod = call.Operand as MethodDefinition;
|
||||
if (calledMethod == null || !calledMethod.IsStatic || calledMethod.DeclaringType != method.DeclaringType)
|
||||
continue;
|
||||
|
||||
localVarSigTokIndex = getInstanceFieldIndex(field);
|
||||
return true;
|
||||
}
|
||||
|
||||
localVarSigTokIndex = -1;
|
||||
return false;
|
||||
}
|
||||
|
||||
static bool findCodeSizeIndex(MethodDefinition method, TypeDefinition methodDataType, out int codeSizeIndex) {
|
||||
var instrs = method.Body.Instructions;
|
||||
for (int i = 0; i < instrs.Count - 1; i++) {
|
||||
var ldfld = instrs[i];
|
||||
if (ldfld.OpCode.Code != Code.Ldfld)
|
||||
continue;
|
||||
var field = ldfld.Operand as FieldDefinition;
|
||||
if (field == null || field.DeclaringType != methodDataType)
|
||||
continue;
|
||||
|
||||
if (instrs[i+1].OpCode.Code != Code.Stfld)
|
||||
continue;
|
||||
|
||||
codeSizeIndex = getInstanceFieldIndex(field);
|
||||
return true;
|
||||
}
|
||||
|
||||
codeSizeIndex = -1;
|
||||
return false;
|
||||
}
|
||||
|
||||
static int getInstanceFieldIndex(FieldDefinition field) {
|
||||
int i = 0;
|
||||
foreach (var f in field.DeclaringType.Fields) {
|
||||
if (f.IsStatic)
|
||||
continue;
|
||||
if (f == field)
|
||||
return i;
|
||||
i++;
|
||||
}
|
||||
throw new ApplicationException("Could not find field");
|
||||
}
|
||||
|
||||
static int findLdfldStind(IList<Instruction> instrs, int index, bool onlyInBlock, bool checkStindi4) {
|
||||
for (int i = index; i < instrs.Count - 1; i++) {
|
||||
var ldfld = instrs[i];
|
||||
if (onlyInBlock && ldfld.OpCode.FlowControl != FlowControl.Next)
|
||||
break;
|
||||
|
||||
if (ldfld.OpCode.Code != Code.Ldfld)
|
||||
continue;
|
||||
|
||||
var stindi4 = instrs[i + 1];
|
||||
if (checkStindi4 && stindi4.OpCode.Code != Code.Stind_I4)
|
||||
continue;
|
||||
|
||||
return i;
|
||||
}
|
||||
return -1;
|
||||
}
|
||||
|
||||
public bool decrypt(PeImage peImage, byte[] fileData, ref DumpedMethods dumpedMethods) {
|
||||
if (initMethod == null)
|
||||
return false;
|
||||
if (peImage.OptionalHeader.checkSum == 0)
|
||||
return false;
|
||||
|
||||
methodsData = decryptMethodsData(peImage);
|
||||
dumpedMethods = decrypt(peImage, fileData);
|
||||
return dumpedMethods != null;
|
||||
}
|
||||
|
||||
byte[] decryptMethodsData(PeImage peImage) {
|
||||
uint mdRva = peImage.OptionalHeader.checkSum ^ (uint)key0;
|
||||
if (peImage.rvaToOffset(mdRva) != peImage.Cor20Header.MetadataOffset)
|
||||
throw new ApplicationException("Invalid metadata rva");
|
||||
var reader = peImage.Reader;
|
||||
reader.BaseStream.Position = getEncryptedHeaderOffset(peImage.Sections);
|
||||
ulong checkSum = reader.ReadUInt64() ^ lkey0;
|
||||
reader.ReadInt32(); // strong name RVA
|
||||
reader.ReadInt32(); // strong name len
|
||||
var iv = reader.ReadBytes(reader.ReadInt32() ^ (int)key2);
|
||||
var encrypted = reader.ReadBytes(reader.ReadInt32() ^ (int)key3);
|
||||
var streamsBuffer = getStreamsBuffer(peImage);
|
||||
if (checkSum != calcChecksum(streamsBuffer))
|
||||
throw new ApplicationException("Invalid checksum. File has been modified.");
|
||||
var decrypted = decrypt(encrypted, iv, streamsBuffer);
|
||||
if (BitConverter.ToInt16(decrypted, 0) != 0x6FD6)
|
||||
throw new ApplicationException("Invalid magic");
|
||||
return decrypted;
|
||||
}
|
||||
|
||||
byte[] decrypt(byte[] encrypted, byte[] iv, byte[] streamsBuffer) {
|
||||
var decrypted = DeobUtils.aesDecrypt(encrypted, DeobUtils.sha256Sum(streamsBuffer), iv);
|
||||
var sha = SHA512.Create();
|
||||
var hash = sha.ComputeHash(streamsBuffer);
|
||||
for (int i = 0; i < decrypted.Length; i += 64) {
|
||||
int j;
|
||||
for (j = 0; j < 64 && i + j < decrypted.Length; j++)
|
||||
decrypted[i + j] ^= (byte)(hash[j] ^ key6);
|
||||
hash = sha.ComputeHash(decrypted, i, j);
|
||||
}
|
||||
return decrypted;
|
||||
}
|
||||
|
||||
static ulong calcChecksum(byte[] data) {
|
||||
var sum = DeobUtils.md5Sum(data);
|
||||
return BitConverter.ToUInt64(sum, 0) ^ BitConverter.ToUInt64(sum, 8);
|
||||
}
|
||||
|
||||
static byte[] getStreamsBuffer(PeImage peImage) {
|
||||
var memStream = new MemoryStream();
|
||||
var writer = new BinaryWriter(memStream);
|
||||
var reader = peImage.Reader;
|
||||
foreach (var mdStream in peImage.Cor20Header.metadata.Streams) {
|
||||
reader.BaseStream.Position = mdStream.Offset;
|
||||
writer.Write(reader.ReadBytes((int)mdStream.length));
|
||||
}
|
||||
return memStream.ToArray();
|
||||
}
|
||||
|
||||
uint getEncryptedHeaderOffset(IList<SectionHeader> sections) {
|
||||
for (int i = sections.Count - 1; i >= 0; i--) {
|
||||
var section = sections[i];
|
||||
if (getSectionNameHash(section) == (uint)key1)
|
||||
return section.pointerToRawData;
|
||||
}
|
||||
throw new ApplicationException("Could not find encrypted section");
|
||||
}
|
||||
|
||||
static uint getSectionNameHash(SectionHeader section) {
|
||||
uint hash = 0;
|
||||
foreach (var c in section.name)
|
||||
hash += c;
|
||||
return hash;
|
||||
}
|
||||
|
||||
DumpedMethods decrypt(PeImage peImage, byte[] fileData) {
|
||||
var dumpedMethods = new DumpedMethods { StringDecrypter = this };
|
||||
|
||||
var metadataTables = peImage.Cor20Header.createMetadataTables();
|
||||
var methodDef = metadataTables.getMetadataType(MetadataIndex.iMethodDef);
|
||||
uint methodDefOffset = methodDef.fileOffset;
|
||||
for (int i = 0; i < methodDef.rows; i++, methodDefOffset += methodDef.totalSize) {
|
||||
uint bodyRva = peImage.offsetReadUInt32(methodDefOffset);
|
||||
if (bodyRva == 0)
|
||||
continue;
|
||||
uint bodyOffset = peImage.rvaToOffset(bodyRva);
|
||||
|
||||
if (!isEncryptedMethod(fileData, (int)bodyOffset))
|
||||
continue;
|
||||
|
||||
var dm = new DumpedMethod();
|
||||
dm.token = (uint)(0x06000001 + i);
|
||||
dm.mdImplFlags = peImage.offsetReadUInt16(methodDefOffset + (uint)methodDef.fields[1].offset);
|
||||
dm.mdFlags = peImage.offsetReadUInt16(methodDefOffset + (uint)methodDef.fields[2].offset);
|
||||
dm.mdName = peImage.offsetRead(methodDefOffset + (uint)methodDef.fields[3].offset, methodDef.fields[3].size);
|
||||
dm.mdSignature = peImage.offsetRead(methodDefOffset + (uint)methodDef.fields[4].offset, methodDef.fields[4].size);
|
||||
dm.mdParamList = peImage.offsetRead(methodDefOffset + (uint)methodDef.fields[5].offset, methodDef.fields[5].size);
|
||||
|
||||
int key = BitConverter.ToInt32(fileData, (int)bodyOffset + 6);
|
||||
int mdOffs = BitConverter.ToInt32(fileData, (int)bodyOffset + 2) ^ key;
|
||||
int len = BitConverter.ToInt32(fileData, (int)bodyOffset + 11) ^ ~key;
|
||||
int methodDataOffset = mdOffs + 2;
|
||||
uint[] methodData;
|
||||
byte[] codeData;
|
||||
decryptMethodData(methodsData, methodDataOffset, (uint)key, len, out methodData, out codeData);
|
||||
|
||||
uint options = 0;
|
||||
int codeSize = 0, numExceptions = 0;
|
||||
for (int j = 0; j < 2; j++) {
|
||||
dm.mhFlags = 0x03;
|
||||
int maxStack = (int)methodData[methodDataIndexes.maxStack];
|
||||
dm.mhMaxStack = (ushort)maxStack;
|
||||
dm.mhLocalVarSigTok = methodData[methodDataIndexes.localVarSigTok];
|
||||
numExceptions = (int)methodData[methodDataIndexes.ehs];
|
||||
options = methodData[methodDataIndexes.options];
|
||||
codeSize = (int)methodData[methodDataIndexes.codeSize];
|
||||
|
||||
// Sometimes the data isn't encrypted!
|
||||
if (maxStack < 0 || maxStack > 0xFFFF ||
|
||||
(dm.mhLocalVarSigTok != 0 && (dm.mhLocalVarSigTok >> 24) != 0x11) ||
|
||||
numExceptions < 0 || numExceptions > 0x1000 ||
|
||||
codeSize < 0 || codeSize > 0x00100000 ||
|
||||
(options & ~0x1FF) != 0) {
|
||||
Buffer.BlockCopy(methodsData, methodDataOffset, methodData, 0, 20);
|
||||
Array.Copy(methodsData, methodDataOffset + 20, codeData, 0, codeData.Length);
|
||||
}
|
||||
else
|
||||
break;
|
||||
}
|
||||
|
||||
var codeDataReader = new BinaryReader(new MemoryStream(codeData));
|
||||
if ((options >> 8) == 0) {
|
||||
dm.code = codeDataReader.ReadBytes(codeSize);
|
||||
dm.extraSections = readExceptionHandlers(codeDataReader, numExceptions);
|
||||
}
|
||||
else {
|
||||
dm.extraSections = readExceptionHandlers(codeDataReader, numExceptions);
|
||||
dm.code = codeDataReader.ReadBytes(codeSize);
|
||||
}
|
||||
if (codeDataReader.BaseStream.Position != codeDataReader.BaseStream.Length)
|
||||
throw new ApplicationException("Invalid method data");
|
||||
if (dm.extraSections != null)
|
||||
dm.mhFlags |= 8;
|
||||
dm.mhCodeSize = (uint)dm.code.Length;
|
||||
|
||||
// Figure out if the original method was tiny or not.
|
||||
bool isTiny = dm.code.Length <= 0x3F &&
|
||||
dm.mhLocalVarSigTok == 0 &&
|
||||
dm.extraSections == null &&
|
||||
dm.mhMaxStack == 8;
|
||||
if (isTiny)
|
||||
dm.mhFlags |= 0x10; // Set 'init locals'
|
||||
dm.mhFlags |= (ushort)(options & 0x10); // copy 'init locals' bit
|
||||
|
||||
dumpedMethods.add(dm);
|
||||
}
|
||||
|
||||
return dumpedMethods;
|
||||
}
|
||||
|
||||
static bool isEncryptedMethod(byte[] fileData, int offset) {
|
||||
return fileData[offset] == 0x46 &&
|
||||
fileData[offset + 1] == 0x21 &&
|
||||
fileData[offset + 10] == 0x20 &&
|
||||
fileData[offset + 15] == 0x26;
|
||||
}
|
||||
|
||||
static byte[] readExceptionHandlers(BinaryReader reader, int numExceptions) {
|
||||
if (numExceptions == 0)
|
||||
return null;
|
||||
|
||||
var memStream = new MemoryStream();
|
||||
var writer = new BinaryWriter(memStream);
|
||||
|
||||
ulong header64 = (ulong)(((numExceptions * 24) << 8) | 0x41);
|
||||
if (header64 > uint.MaxValue)
|
||||
throw new ApplicationException("Too many exception handlers...");
|
||||
writer.Write((uint)header64);
|
||||
for (int i = 0; i < numExceptions; i++) {
|
||||
writer.Write(reader.ReadUInt32()); // flags
|
||||
writer.Write(reader.ReadUInt32()); // try offset
|
||||
writer.Write(reader.ReadUInt32()); // try length
|
||||
writer.Write(reader.ReadUInt32()); // handler offset
|
||||
writer.Write(reader.ReadUInt32()); // handler length
|
||||
writer.Write(reader.ReadUInt32()); // catch token or filter offset
|
||||
}
|
||||
|
||||
return memStream.ToArray();
|
||||
}
|
||||
|
||||
void decryptMethodData(byte[] fileData, int offset, uint k1, int size, out uint[] methodData, out byte[] codeData) {
|
||||
var data = new byte[size];
|
||||
Array.Copy(fileData, offset, data, 0, data.Length);
|
||||
uint k2 = key4 * k1;
|
||||
for (int i = 0; i < data.Length; i++) {
|
||||
data[i] ^= (byte)k2;
|
||||
k2 = (byte)((k2 * data[i] + k1) % 0xFF);
|
||||
}
|
||||
|
||||
methodData = new uint[5];
|
||||
Buffer.BlockCopy(data, 0, methodData, 0, 20);
|
||||
codeData = new byte[size - 20];
|
||||
Array.Copy(data, 20, codeData, 0, codeData.Length);
|
||||
}
|
||||
|
||||
string IStringDecrypter.decrypt(uint token) {
|
||||
if ((token & 0xFF800000) != 0x70800000)
|
||||
return null;
|
||||
var reader = new BinaryReader(new MemoryStream(methodsData));
|
||||
reader.BaseStream.Position = (token & ~0xFF800000) + 2;
|
||||
int len = reader.ReadInt32();
|
||||
if ((len & 1) != 1)
|
||||
throw new ApplicationException("Invalid string len");
|
||||
int chars = len / 2;
|
||||
var sb = new StringBuilder(chars);
|
||||
for (int i = 0; i < chars; i++)
|
||||
sb.Append((char)(reader.ReadUInt16() ^ key5));
|
||||
return sb.ToString();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -76,19 +76,6 @@ namespace de4dot.code.deobfuscators.Unknown {
|
|||
obfuscatorName = string.Format("{0} (not supported)", name);
|
||||
}
|
||||
|
||||
public override int earlyDetect() {
|
||||
setName(earlyScanTypes());
|
||||
return obfuscatorName != null ? 1 : 0;
|
||||
}
|
||||
|
||||
string earlyScanTypes() {
|
||||
foreach (var type in module.Types) {
|
||||
if (type.FullName == "ConfusedByAttribute")
|
||||
return "Confuser";
|
||||
}
|
||||
return null;
|
||||
}
|
||||
|
||||
protected override int detectInternal() {
|
||||
setName(scanTypes());
|
||||
return 1;
|
||||
|
|
|
|||
|
|
@ -42,6 +42,7 @@ namespace de4dot.cui {
|
|||
new de4dot.code.deobfuscators.CodeFort.DeobfuscatorInfo(),
|
||||
new de4dot.code.deobfuscators.CodeVeil.DeobfuscatorInfo(),
|
||||
new de4dot.code.deobfuscators.CodeWall.DeobfuscatorInfo(),
|
||||
new de4dot.code.deobfuscators.Confuser.DeobfuscatorInfo(),
|
||||
new de4dot.code.deobfuscators.CryptoObfuscator.DeobfuscatorInfo(),
|
||||
new de4dot.code.deobfuscators.DeepSea.DeobfuscatorInfo(),
|
||||
new de4dot.code.deobfuscators.Dotfuscator.DeobfuscatorInfo(),
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user