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Merge other proxy method class with the V10 one

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This commit is contained in:
de4dot 2012-08-08 17:38:38 +02:00
parent 94acbc7131
commit a2798908b0
3 changed files with 134 additions and 290 deletions
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16
de4dot.code/deobfuscators/Confuser/Deobfuscator.cs
View File

@ -73,7 +73,6 @@ namespace de4dot.code.deobfuscators.Confuser {
List<EmbeddedAssemblyInfo> embeddedAssemblyInfos = new List<EmbeddedAssemblyInfo>();
JitMethodsDecrypter jitMethodsDecrypter;
MemoryMethodsDecrypter memoryMethodsDecrypter;
ProxyCallFixer proxyCallFixer;
ProxyCallFixerV10 proxyCallFixerV10;
AntiDebugger antiDebugger;
AntiDumping antiDumping;
@ -134,7 +133,6 @@ namespace de4dot.code.deobfuscators.Confuser {
int sum = toInt32(jitMethodsDecrypter != null ? jitMethodsDecrypter.Detected : false) +
toInt32(memoryMethodsDecrypter != null ? memoryMethodsDecrypter.Detected : false) +
toInt32(proxyCallFixer != null ? proxyCallFixer.Detected : false) +
toInt32(proxyCallFixerV10 != null ? proxyCallFixerV10.Detected : false) +
toInt32(antiDebugger != null ? antiDebugger.Detected : false) +
toInt32(antiDumping != null ? antiDumping.Detected : false) +
@ -191,12 +189,8 @@ namespace de4dot.code.deobfuscators.Confuser {
}
} while (false);
proxyCallFixer = new ProxyCallFixer(module, getFileData(), DeobfuscatedFile);
proxyCallFixer.findDelegateCreator();
if (!proxyCallFixer.Detected) {
proxyCallFixerV10 = new ProxyCallFixerV10(module, getFileData());
proxyCallFixerV10.findDelegateCreator(DeobfuscatedFile);
}
proxyCallFixerV10 = new ProxyCallFixerV10(module, getFileData());
proxyCallFixerV10.findDelegateCreator(DeobfuscatedFile);
antiDebugger = new AntiDebugger(module);
antiDebugger.find();
antiDumping = new AntiDumping(module);
@ -346,8 +340,6 @@ namespace de4dot.code.deobfuscators.Confuser {
addTypeToBeRemoved(antiDumping.Type, "Anti dumping type");
}
if (proxyCallFixer != null)
proxyCallFixer.find();
if (proxyCallFixerV10 != null)
proxyCallFixerV10.find();
@ -503,8 +495,6 @@ namespace de4dot.code.deobfuscators.Confuser {
}
public override void deobfuscateMethodEnd(Blocks blocks) {
if (proxyCallFixer != null)
proxyCallFixer.deobfuscate(blocks);
if (proxyCallFixerV10 != null)
proxyCallFixerV10.deobfuscate(blocks);
resourceDecrypter.deobfuscate(blocks);
@ -519,8 +509,6 @@ namespace de4dot.code.deobfuscators.Confuser {
}
public override void deobfuscateEnd() {
if (proxyCallFixer != null)
removeProxyDelegates(proxyCallFixer);
if (proxyCallFixerV10 != null) {
if (removeProxyDelegates(proxyCallFixerV10))
addFieldsToBeRemoved(proxyCallFixerV10.Fields, "Proxy delegate instance field");

274
de4dot.code/deobfuscators/Confuser/ProxyCallFixer.cs
View File

@ -1,274 +0,0 @@
/*
Copyright (C) 2011-2012 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 Mono.Cecil;
using Mono.Cecil.Cil;
using de4dot.blocks;
using de4dot.PE;
namespace de4dot.code.deobfuscators.Confuser {
// Since 1.8 r75367
class ProxyCallFixer : ProxyCallFixer2 {
byte[] fileData;
ISimpleDeobfuscator simpleDeobfuscator;
MethodDefinitionAndDeclaringTypeDict<ProxyCreatorInfo> methodToInfo = new MethodDefinitionAndDeclaringTypeDict<ProxyCreatorInfo>();
FieldDefinitionAndDeclaringTypeDict<MethodDefinition> fieldToMethod = new FieldDefinitionAndDeclaringTypeDict<MethodDefinition>();
x86Emulator x86emu;
enum ProxyCreatorType {
None,
CallOrCallvirt,
Newobj,
}
class ProxyCreatorInfo {
public readonly MethodDefinition creatorMethod;
public readonly ProxyCreatorType proxyCreatorType;
public uint? key;
public MethodDefinition nativeMethod;
public ushort callvirtChar;
public ProxyCreatorInfo(MethodDefinition creatorMethod, ProxyCreatorType proxyCreatorType) {
this.creatorMethod = creatorMethod;
this.proxyCreatorType = proxyCreatorType;
}
}
protected override bool ProxyCallIsObfuscated {
get { return true; }
}
public override IEnumerable<Tuple<MethodDefinition, string>> OtherMethods {
get {
var list = new List<Tuple<MethodDefinition, string>>();
foreach (var info in methodToInfo.getValues()) {
list.Add(new Tuple<MethodDefinition, string> {
Item1 = info.creatorMethod,
Item2 = "Delegate creator method",
});
list.Add(new Tuple<MethodDefinition, string> {
Item1 = info.nativeMethod,
Item2 = "Calculate RID native method",
});
}
return list;
}
}
public ProxyCallFixer(ModuleDefinition module, byte[] fileData, ISimpleDeobfuscator simpleDeobfuscator)
: base(module) {
this.fileData = fileData;
this.simpleDeobfuscator = simpleDeobfuscator;
}
protected override object checkCctor(TypeDefinition type, MethodDefinition cctor) {
var instrs = cctor.Body.Instructions;
object retVal = null;
for (int i = 0; i < instrs.Count - 1; i++) {
var ldtoken = instrs[i];
if (ldtoken.OpCode.Code != Code.Ldtoken)
continue;
var field = ldtoken.Operand as FieldDefinition;
if (field == null)
continue;
var call = instrs[i + 1];
if (call.OpCode.Code != Code.Call)
continue;
var calledMethod = call.Operand as MethodDefinition;
if (!isDelegateCreatorMethod(calledMethod))
continue;
fieldToMethod.add(field, calledMethod);
retVal = this;
}
return retVal;
}
protected override void getCallInfo(object context, FieldDefinition field, out MethodReference calledMethod, out OpCode callOpcode) {
var info = getProxyCreatorInfo(field);
var sig = module.GetSignatureBlob(field);
int len = sig.Length;
uint magic = (uint)((sig[len - 2] << 24) | (sig[len - 3] << 16) | (sig[len - 5] << 8) | sig[len - 6]);
uint rid = getRid(info, magic);
int token = (sig[len - 7] << 24) | (int)rid;
calledMethod = module.LookupToken(token) as MethodReference;
callOpcode = getCallOpCode(info, field);
}
OpCode getCallOpCode(ProxyCreatorInfo info, FieldDefinition field) {
switch (info.proxyCreatorType) {
case ProxyCreatorType.CallOrCallvirt:
if (field.Name.Length > 0 && field.Name[0] == info.callvirtChar)
return OpCodes.Callvirt;
return OpCodes.Call;
case ProxyCreatorType.Newobj:
return OpCodes.Newobj;
default: throw new NotSupportedException();
}
}
ProxyCreatorInfo getProxyCreatorInfo(FieldReference field) {
return methodToInfo.find(fieldToMethod.find(field));
}
uint getRid(ProxyCreatorInfo info, uint magic) {
if (info.key != null)
return magic ^ info.key.Value;
if (info.nativeMethod != null) {
if (x86emu == null)
x86emu = new x86Emulator(new PeImage(fileData));
return x86emu.emulate((uint)info.nativeMethod.RVA, magic);
}
throw new NotImplementedException();
}
public void findDelegateCreator() {
var type = DotNetUtils.getModuleType(module);
if (type == null)
return;
foreach (var method in type.Methods) {
if (!method.IsStatic || method.Body == null)
continue;
if (!DotNetUtils.isMethod(method, "System.Void", "(System.RuntimeFieldHandle)"))
continue;
var creatorType = getProxyCreatorType(method);
if (creatorType == ProxyCreatorType.None)
continue;
if (!DotNetUtils.callsMethod(method, "System.Byte[] System.Reflection.Module::ResolveSignature(System.Int32)"))
continue;
if (!DotNetUtils.callsMethod(method, "System.Reflection.MethodBase System.Reflection.Module::ResolveMethod(System.Int32)"))
continue;
methodToInfo.add(method, createProxyCreatorInfo(method, creatorType));
setDelegateCreatorMethod(method);
}
}
static ProxyCreatorType getProxyCreatorType(MethodDefinition method) {
foreach (var instr in method.Body.Instructions) {
var field = instr.Operand as FieldReference;
if (field == null)
continue;
switch (field.FullName) {
case "System.Reflection.Emit.OpCode System.Reflection.Emit.OpCodes::Call":
case "System.Reflection.Emit.OpCode System.Reflection.Emit.OpCodes::Callvirt":
return ProxyCreatorType.CallOrCallvirt;
case "System.Reflection.Emit.OpCode System.Reflection.Emit.OpCodes::Newobj":
return ProxyCreatorType.Newobj;
}
}
return ProxyCreatorType.None;
}
ProxyCreatorInfo createProxyCreatorInfo(MethodDefinition creatorMethod, ProxyCreatorType proxyCreatorType) {
simpleDeobfuscator.deobfuscate(creatorMethod, true);
var info = new ProxyCreatorInfo(creatorMethod, proxyCreatorType);
if (!initializeKey(info))
throw new NotSupportedException("Couldn't find decryption key");
if (info.proxyCreatorType == ProxyCreatorType.CallOrCallvirt) {
if (!initializeCallvirtChar(info))
throw new ApplicationException("Couldn't find callvirt char");
}
return info;
}
bool initializeKey(ProxyCreatorInfo info) {
var instrs = info.creatorMethod.Body.Instructions;
for (int index = 0; index < instrs.Count; index++) {
index = ConfuserUtils.findCallMethod(instrs, index, Code.Callvirt, "System.Reflection.Module System.Reflection.MemberInfo::get_Module()");
if (index < 0)
break;
uint key;
if (getKey(instrs, index + 1, out key)) {
info.key = key;
return true;
}
var nativeMethod = getNativeMethod(instrs, index + 1);
if (nativeMethod != null) {
info.nativeMethod = nativeMethod;
return true;
}
}
return false;
}
static bool getKey(IList<Instruction> instrs, int index, out uint key) {
key = 0;
if (index + 2 >= instrs.Count)
return false;
if (!DotNetUtils.isLdloc(instrs[index++]))
return false;
var ldci4 = instrs[index++];
if (!DotNetUtils.isLdcI4(ldci4))
return false;
if (instrs[index++].OpCode.Code != Code.Xor)
return false;
key = (uint)DotNetUtils.getLdcI4Value(ldci4);
return true;
}
static MethodDefinition getNativeMethod(IList<Instruction> instrs, int index) {
if (index + 1 >= instrs.Count)
return null;
if (!DotNetUtils.isLdloc(instrs[index++]))
return null;
var call = instrs[index++];
if (call.OpCode.Code != Code.Call)
return null;
var calledMethod = call.Operand as MethodDefinition;
if (calledMethod == null || calledMethod.Body != null || !calledMethod.IsNative)
return null;
return calledMethod;
}
bool initializeCallvirtChar(ProxyCreatorInfo info) {
var instrs = info.creatorMethod.Body.Instructions;
for (int index = 0; index < instrs.Count; index++) {
index = ConfuserUtils.findCallMethod(instrs, index, Code.Callvirt, "System.Char System.String::get_Chars(System.Int32)");
if (index < 0)
break;
index++;
if (index >= instrs.Count)
break;
var ldci4 = instrs[index];
if (!DotNetUtils.isLdcI4(ldci4))
continue;
info.callvirtChar = (ushort)DotNetUtils.getLdcI4Value(ldci4);
return true;
}
return false;
}
}
}

134
de4dot.code/deobfuscators/Confuser/ProxyCallFixerV10.cs
View File

@ -34,6 +34,7 @@ namespace de4dot.code.deobfuscators.Confuser {
ConfuserVersion version = ConfuserVersion.Unknown;
byte[] fileData;
x86Emulator x86emu;
ushort callvirtChar;
enum ConfuserVersion {
Unknown,
@ -45,6 +46,8 @@ namespace de4dot.code.deobfuscators.Confuser {
v17_r73740_native,
v17_r74708_normal,
v17_r74708_native,
v18_r75367_normal,
v18_r75367_native,
}
enum ProxyCreatorType {
@ -59,13 +62,15 @@ namespace de4dot.code.deobfuscators.Confuser {
public readonly ConfuserVersion version;
public readonly uint magic;
public readonly MethodDefinition nativeMethod;
public readonly ushort callvirtChar;
public ProxyCreatorInfo(MethodDefinition creatorMethod, ProxyCreatorType proxyCreatorType, ConfuserVersion version, uint magic, MethodDefinition nativeMethod) {
public ProxyCreatorInfo(MethodDefinition creatorMethod, ProxyCreatorType proxyCreatorType, ConfuserVersion version, uint magic, MethodDefinition nativeMethod, ushort callvirtChar) {
this.creatorMethod = creatorMethod;
this.proxyCreatorType = proxyCreatorType;
this.version = version;
this.magic = magic;
this.nativeMethod = nativeMethod;
this.callvirtChar = callvirtChar;
}
}
@ -206,6 +211,14 @@ namespace de4dot.code.deobfuscators.Confuser {
getCallInfo_v17_r73740_native(info, creatorInfo, out calledMethod, out callOpcode);
break;
case ConfuserVersion.v18_r75367_normal:
getCallInfo_v18_r75367_normal(info, creatorInfo, out calledMethod, out callOpcode);
break;
case ConfuserVersion.v18_r75367_native:
getCallInfo_v18_r75367_native(info, creatorInfo, out calledMethod, out callOpcode);
break;
default:
throw new ApplicationException("Unknown version");
}
@ -366,6 +379,45 @@ namespace de4dot.code.deobfuscators.Confuser {
callOpcode = getCallOpCode(creatorInfo, isCallvirt);
}
void getCallInfo_v18_r75367_normal(DelegateInitInfo info, ProxyCreatorInfo creatorInfo, out MethodReference calledMethod, out OpCode callOpcode) {
getCallInfo_v18_r75367(info, creatorInfo, out calledMethod, out callOpcode, (creatorInfo2, magic) => creatorInfo2.magic ^ magic);
}
void getCallInfo_v18_r75367_native(DelegateInitInfo info, ProxyCreatorInfo creatorInfo, out MethodReference calledMethod, out OpCode callOpcode) {
getCallInfo_v18_r75367(info, creatorInfo, out calledMethod, out callOpcode, (creatorInfo2, magic) => {
if (x86emu == null)
x86emu = new x86Emulator(new PeImage(fileData));
return x86emu.emulate((uint)creatorInfo2.nativeMethod.RVA, magic);
});
}
void getCallInfo_v18_r75367(DelegateInitInfo info, ProxyCreatorInfo creatorInfo, out MethodReference calledMethod, out OpCode callOpcode, Func<ProxyCreatorInfo, uint, uint> getRid) {
var sig = module.GetSignatureBlob(info.field);
int len = sig.Length;
uint magic = (uint)((sig[len - 2] << 24) | (sig[len - 3] << 16) | (sig[len - 5] << 8) | sig[len - 6]);
uint rid = getRid(creatorInfo, magic);
int token = (sig[len - 7] << 24) | (int)rid;
uint table = (uint)token >> 24;
if (table != 6 && table != 0x0A && table != 0x2B)
throw new ApplicationException("Invalid method token");
calledMethod = module.LookupToken(token) as MethodReference;
callOpcode = getCallOpCode(creatorInfo, info.field);
}
static OpCode getCallOpCode(ProxyCreatorInfo info, FieldDefinition field) {
switch (info.proxyCreatorType) {
case ProxyCreatorType.CallOrCallvirt:
if (field.Name.Length > 0 && field.Name[0] == info.callvirtChar)
return OpCodes.Callvirt;
return OpCodes.Call;
case ProxyCreatorType.Newobj:
return OpCodes.Newobj;
default: throw new NotSupportedException();
}
}
// A method token is not a stable value so this method can fail to return the correct method!
// There's nothing I can do about that. It's an obfuscator bug. It was fixed in 1.3 r55346.
MethodReference createMethodReference(AssemblyNameReference asmRef, uint methodToken) {
@ -413,6 +465,8 @@ namespace de4dot.code.deobfuscators.Confuser {
public void findDelegateCreator(ISimpleDeobfuscator simpleDeobfuscator) {
var type = DotNetUtils.getModuleType(module);
if (type == null)
return;
foreach (var method in type.Methods) {
if (method.Body == null || !method.IsStatic || !method.IsAssembly)
continue;
@ -438,6 +492,17 @@ namespace de4dot.code.deobfuscators.Confuser {
else
theVersion = ConfuserVersion.v14_r58857;
}
else if (!DotNetUtils.callsMethod(method, "System.Byte[] System.Convert::FromBase64String(System.String)") &&
DotNetUtils.callsMethod(method, "System.Reflection.MethodBase System.Reflection.Module::ResolveMethod(System.Int32)")) {
if (proxyType == ProxyCreatorType.CallOrCallvirt && !findCallvirtChar(method, out callvirtChar))
continue;
if ((nativeMethod = findNativeMethod_v18_r75367(method)) != null)
theVersion = ConfuserVersion.v18_r75367_native;
else if (findMagic_v18_r75367(method, out magic))
theVersion = ConfuserVersion.v18_r75367_normal;
else
continue;
}
else if (is_v17_r73740(method)) {
if (DotNetUtils.callsMethod(method, "System.Boolean System.Type::get_IsArray()")) {
if ((nativeMethod = findNativeMethod_v17_r73740(method)) != null)
@ -458,11 +523,55 @@ namespace de4dot.code.deobfuscators.Confuser {
}
setDelegateCreatorMethod(method);
methodToInfo.add(method, new ProxyCreatorInfo(method, proxyType, theVersion, magic, nativeMethod));
methodToInfo.add(method, new ProxyCreatorInfo(method, proxyType, theVersion, magic, nativeMethod, callvirtChar));
version = theVersion;
}
}
static bool findMagic_v18_r75367(MethodDefinition method, out uint magic) {
var instrs = method.Body.Instructions;
for (int i = 0; i < instrs.Count; i++) {
i = ConfuserUtils.findCallMethod(instrs, i, Code.Callvirt, "System.Reflection.Module System.Reflection.MemberInfo::get_Module()");
if (i < 0 || i + 3 >= instrs.Count)
break;
if (!DotNetUtils.isLdloc(instrs[i + 1]))
continue;
var ldci4 = instrs[i + 2];
if (!DotNetUtils.isLdcI4(ldci4))
continue;
if (instrs[i+3].OpCode.Code != Code.Xor)
continue;
magic = (uint)DotNetUtils.getLdcI4Value(ldci4);
return true;
}
magic = 0;
return false;
}
static MethodDefinition findNativeMethod_v18_r75367(MethodDefinition method) {
var instrs = method.Body.Instructions;
for (int i = 0; i < instrs.Count; i++) {
i = ConfuserUtils.findCallMethod(instrs, i, Code.Callvirt, "System.Reflection.Module System.Reflection.MemberInfo::get_Module()");
if (i < 0 || i + 2 >= instrs.Count)
break;
if (!DotNetUtils.isLdloc(instrs[i + 1]))
continue;
var call = instrs[i + 2];
if (call.OpCode.Code != Code.Call)
continue;
var calledMethod = call.Operand as MethodDefinition;
if (calledMethod == null || calledMethod.Body != null || !calledMethod.IsNative)
continue;
return calledMethod;
}
return null;
}
static bool findMagic_v17_r73740(MethodDefinition method, out uint magic) {
var instrs = method.Body.Instructions;
for (int i = 0; i < instrs.Count; i++) {
@ -743,6 +852,27 @@ namespace de4dot.code.deobfuscators.Confuser {
return foundInvoke ? field : null;
}
static bool findCallvirtChar(MethodDefinition method, out ushort callvirtChar) {
var instrs = method.Body.Instructions;
for (int index = 0; index < instrs.Count; index++) {
index = ConfuserUtils.findCallMethod(instrs, index, Code.Callvirt, "System.Char System.String::get_Chars(System.Int32)");
if (index < 0)
break;
index++;
if (index >= instrs.Count)
break;
var ldci4 = instrs[index];
if (!DotNetUtils.isLdcI4(ldci4))
continue;
callvirtChar = (ushort)DotNetUtils.getLdcI4Value(ldci4);
return true;
}
callvirtChar = 0;
return false;
}
public void cleanUp() {
if (!Detected)
return;