monocul.us/de4dot-cex
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Decrypt library mode files

Browse Source
This commit is contained in:
de4dot 2011-12-21 00:31:27 +01:00
parent 15b4cefe89
commit c516d61ad7
4 changed files with 295 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
de4dot.code/de4dot.code.csproj
View File

@ -79,7 +79,9 @@
<Compile Include="deobfuscators\Dotfuscator\Deobfuscator.cs" />
<Compile Include="deobfuscators\dotNET_Reactor3\ApplicationModeDecrypter.cs" />
<Compile Include="deobfuscators\dotNET_Reactor3\ApplicationModeUnpacker.cs" />
<Compile Include="deobfuscators\dotNET_Reactor3\DecrypterType.cs" />
<Compile Include="deobfuscators\dotNET_Reactor3\Deobfuscator.cs" />
<Compile Include="deobfuscators\dotNET_Reactor3\NativeLibSaver.cs" />
<Compile Include="deobfuscators\dotNET_Reactor4\AssemblyResolver.cs" />
<Compile Include="deobfuscators\dotNET_Reactor4\BooleanDecrypter.cs" />
<Compile Include="deobfuscators\dotNET_Reactor4\BoolValueInliner.cs" />

117
de4dot.code/deobfuscators/dotNET_Reactor3/DecrypterType.cs Normal file
View File

@ -0,0 +1,117 @@
/*
Copyright (C) 2011 de4dot@gmail.com
This file is part of de4dot.
de4dot is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
de4dot is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with de4dot. If not, see <http://www.gnu.org/licenses/>.
*/
using System;
using System.Collections.Generic;
using System.Text;
using Mono.Cecil;
using de4dot.blocks;
namespace de4dot.code.deobfuscators.dotNET_Reactor3 {
// Find the type that decrypts strings and calls the native lib
class DecrypterType {
ModuleDefinition module;
TypeDefinition decrypterType;
MethodDefinition stringDecrypter1;
MethodDefinition stringDecrypter2;
List<MethodDefinition> initMethods = new List<MethodDefinition>();
public bool Detected {
get { return decrypterType != null; }
}
public TypeDefinition Type {
get { return decrypterType; }
}
public MethodDefinition StringDecrypter1 {
get { return stringDecrypter1; }
}
public MethodDefinition StringDecrypter2 {
get { return stringDecrypter2; }
}
public IEnumerable<MethodDefinition> InitMethods {
get { return initMethods; }
}
public IEnumerable<MethodDefinition> StringDecrypters {
get {
return new List<MethodDefinition> {
stringDecrypter1,
stringDecrypter2,
};
}
}
public DecrypterType(ModuleDefinition module) {
this.module = module;
}
public DecrypterType(ModuleDefinition module, DecrypterType oldOne) {
this.module = module;
this.decrypterType = lookup(oldOne.decrypterType, "Could not find decrypterType");
this.stringDecrypter1 = lookup(oldOne.stringDecrypter1, "Could not find stringDecrypter1");
this.stringDecrypter2 = lookup(oldOne.stringDecrypter2, "Could not find stringDecrypter2");
foreach (var method in oldOne.initMethods)
initMethods.Add(lookup(method, "Could not find initMethod"));
}
T lookup<T>(T def, string errorMessage) where T : MemberReference {
return DeobUtils.lookup(module, def, errorMessage);
}
public void find() {
foreach (var type in module.Types) {
if (type.FullName != "<PrivateImplementationDetails>{B4838DC1-AC79-43d1-949F-41B518B904A8}")
continue;
decrypterType = type;
stringDecrypter1 = addStringDecrypter(type, "CS$0$0004");
stringDecrypter2 = addStringDecrypter(type, "CS$0$0005");
foreach (var method in type.Methods) {
if (DotNetUtils.isMethod(method, "System.Void", "()"))
initMethods.Add(method);
}
return;
}
}
MethodDefinition addStringDecrypter(TypeDefinition type, string name) {
var method = DotNetUtils.getMethod(type, name);
if (method == null)
return null;
if (!DotNetUtils.isMethod(method, "System.String", "(System.String)"))
return null;
return method;
}
public string decrypt1(string s) {
var sb = new StringBuilder(s.Length);
foreach (var c in s)
sb.Append((char)(0xFF - (byte)c));
return sb.ToString();
}
public string decrypt2(string s) {
return Encoding.Unicode.GetString(Convert.FromBase64String(s));
}
}
}

56
de4dot.code/deobfuscators/dotNET_Reactor3/Deobfuscator.cs
View File

@ -81,9 +81,12 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor3 {
Options options;
string obfuscatorName = DeobfuscatorInfo.THE_NAME;
DecrypterType decrypterType;
NativeLibSaver nativeLibSaver;
List<UnpackedFile> unpackedFiles = new List<UnpackedFile>();
bool unpackedNativeFile = false;
bool canRemoveDecrypterType = true;
bool startedDeobfuscating = false;
internal class Options : OptionsBase {
@ -132,6 +135,27 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor3 {
return data;
}
public override bool getDecryptedModule(ref byte[] newFileData, ref Dictionary<uint, DumpedMethod> dumpedMethods) {
if (!nativeLibSaver.Detected)
return false;
var fileData = ModuleBytes ?? DeobUtils.readModule(module);
var peImage = new PeImage(fileData);
if (!nativeLibSaver.patch(peImage))
return false;
newFileData = fileData;
return true;
}
public override IDeobfuscator moduleReloaded(ModuleDefinition module) {
var newOne = new Deobfuscator(options);
newOne.setModule(module);
newOne.decrypterType = new DecrypterType(module, decrypterType);
newOne.nativeLibSaver = new NativeLibSaver(module, nativeLibSaver);
return newOne;
}
public override void init(ModuleDefinition module) {
base.init(module);
}
@ -194,6 +218,12 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor3 {
if (unpackedNativeFile)
val += 100;
int sum = convert(unpackedNativeFile) +
convert(decrypterType.Detected) +
convert(nativeLibSaver.Detected);
if (sum > 0)
val += 100 + 10 * (sum - 1);
return val;
}
@ -202,6 +232,10 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor3 {
}
protected override void scanForObfuscator() {
decrypterType = new DecrypterType(module);
decrypterType.find();
nativeLibSaver = new NativeLibSaver(module);
nativeLibSaver.find();
obfuscatorName = detectVersion();
if (unpackedNativeFile)
obfuscatorName += " (native)";
@ -214,6 +248,23 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor3 {
public override void deobfuscateBegin() {
base.deobfuscateBegin();
staticStringDecrypter.add(decrypterType.StringDecrypter1, (method2, args) => {
return decrypterType.decrypt1((string)args[0]);
});
staticStringDecrypter.add(decrypterType.StringDecrypter2, (method2, args) => {
return decrypterType.decrypt2((string)args[0]);
});
if (Operations.DecryptStrings == OpDecryptString.None)
canRemoveDecrypterType = false;
addCctorInitCallToBeRemoved(nativeLibSaver.InitMethod);
addResourceToBeRemoved(nativeLibSaver.Resource, "Native lib resource");
addTypeToBeRemoved(nativeLibSaver.Type, "Native lib saver type");
foreach (var initMethod in decrypterType.InitMethods)
addCctorInitCallToBeRemoved(initMethod);
dumpUnpackedFiles();
startedDeobfuscating = true;
@ -229,6 +280,9 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor3 {
if (options.RestoreTypes)
new TypesRestorer(module).deobfuscate();
if (canRemoveDecrypterType && !isTypeCalled(decrypterType.Type))
addTypeToBeRemoved(decrypterType.Type, "Decrypter type");
base.deobfuscateEnd();
}
@ -240,6 +294,8 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor3 {
public override IEnumerable<string> getStringDecrypterMethods() {
var list = new List<string>();
foreach (var method in decrypterType.StringDecrypters)
list.Add(method.MetadataToken.ToInt32().ToString("X8"));
return list;
}
}

120
de4dot.code/deobfuscators/dotNET_Reactor3/NativeLibSaver.cs Normal file
View File

@ -0,0 +1,120 @@
/*
Copyright (C) 2011 de4dot@gmail.com
This file is part of de4dot.
de4dot is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
de4dot is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with de4dot. If not, see <http://www.gnu.org/licenses/>.
*/
using System;
using Mono.Cecil;
using de4dot.blocks;
using de4dot.code.PE;
namespace de4dot.code.deobfuscators.dotNET_Reactor3 {
// Finds the type that saves the native lib (if in resources) to disk
class NativeLibSaver {
ModuleDefinition module;
TypeDefinition nativeLibCallerType;
MethodDefinition initMethod;
Resource nativeFileResource;
public TypeDefinition Type {
get { return nativeLibCallerType; }
}
public MethodDefinition InitMethod {
get { return initMethod; }
}
public Resource Resource {
get { return nativeFileResource; }
}
public bool Detected {
get { return nativeLibCallerType != null; }
}
public NativeLibSaver(ModuleDefinition module) {
this.module = module;
}
public NativeLibSaver(ModuleDefinition module, NativeLibSaver oldOne) {
this.module = module;
this.nativeLibCallerType = lookup(oldOne.nativeLibCallerType, "Could not find nativeLibCallerType");
this.initMethod = lookup(oldOne.initMethod, "Could not find initMethod");
if (oldOne.nativeFileResource != null) {
this.nativeFileResource = DotNetUtils.getResource(module, oldOne.nativeFileResource.Name);
if (this.nativeFileResource == null)
throw new ApplicationException("Could not find nativeFileResource");
}
}
T lookup<T>(T def, string errorMessage) where T : MemberReference {
return DeobUtils.lookup(module, def, errorMessage);
}
public void find() {
foreach (var info in DotNetUtils.getCalledMethods(module, DotNetUtils.getMethod(DotNetUtils.getModuleType(module), ".cctor"))) {
if (!DotNetUtils.isMethod(info.Item2, "System.Void", "()"))
continue;
if (info.Item1.FullName != "<PrivateImplementationDetails>{F1C5056B-0AFC-4423-9B83-D13A26B48869}")
continue;
nativeLibCallerType = info.Item1;
initMethod = info.Item2;
foreach (var s in DotNetUtils.getCodeStrings(initMethod)) {
nativeFileResource = DotNetUtils.getResource(module, s);
if (nativeFileResource != null)
break;
}
return;
}
}
public bool patch(PeImage peImage) {
try {
return patch2(peImage);
}
catch {
Log.w("Could not patch the file");
return false;
}
}
bool patch2(PeImage peImage) {
uint numPatches = peImage.offsetReadUInt32(peImage.ImageLength - 4);
uint offset = checked(peImage.ImageLength - 4 - numPatches * 8);
const uint magic = 2749;
for (uint i = 0; i < numPatches; i++, offset += 8) {
uint rva = checked((peImage.offsetReadUInt32(offset) - magic) / 3);
var value = peImage.offsetReadUInt32(offset + 4);
if (value == 4) {
i++;
offset += 8;
rva = checked((peImage.offsetReadUInt32(offset) - magic) / 3);
value = peImage.offsetReadUInt32(offset);
}
else
value = checked((value - magic) / 3);
peImage.dotNetSafeWrite(rva, BitConverter.GetBytes(value));
}
return true;
}
}
}