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Fixes in AssemblyResolver and MethodDecrypter #3

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Fixes in AssemblyResolver and MethodDecrypter #3

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8 changes: 7 additions & 1 deletion NETReactorSlayer.Core/Stages/AssemblyResolver.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -35,8 +35,14 @@ public void Run(IContext context)
return;

var assemblies = new List<EmbeddedResource>();
foreach (var prefix in DotNetUtils.GetCodeStrings(_resolverMethod).Distinct())
foreach (var prefix in DotNetUtils.GetCodeStrings(_resolverMethod).Where(s => !string.IsNullOrEmpty(s) &&
!s.StartsWith("@") &&
!s.StartsWith("-") &&
!s.StartsWith(".") &&
!s.Contains("ANDROID")).Distinct())
{
assemblies.AddRange(GetAssemblies(prefix));
}
if (assemblies.Count < 1)
return;

Expand Down
55 changes: 53 additions & 2 deletions NETReactorSlayer.Core/Stages/MethodDecrypter.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -33,7 +33,7 @@ public void Run(IContext context)
Context = context;
try
{
if (!Find() && !Find2())
if (!Find() && !Find2() && !Find3())
{
Context.Logger.Warn("Couldn't find any encrypted method.");
return;
Expand Down Expand Up @@ -65,7 +65,9 @@ private bool Find()
where DotNetUtils.IsMethod(method, "System.UInt32",
"(System.IntPtr,System.IntPtr,System.IntPtr,System.UInt32,System.IntPtr,System.UInt32&)") ||
DotNetUtils.IsMethod(method, "System.UInt32",
"(System.UInt64&,System.IntPtr,System.IntPtr,System.UInt32,System.IntPtr&,System.UInt32&)")
"(System.UInt64&,System.IntPtr,System.IntPtr,System.UInt32,System.IntPtr&,System.UInt32&)") ||
DotNetUtils.IsMethod(method, "System.Int32",
"(System.IntPtr,System.IntPtr,System.Byte[],System.UInt32,System.IntPtr&)")
from methodDef in from x in method.DeclaringType.Methods
where x.IsStatic && x.HasBody && x.Body.HasInstructions
select x
Expand Down Expand Up @@ -114,6 +116,55 @@ private bool Find2()
return false;
}

private bool Find3()
{
Func<MethodDef, bool> hasRequiredLocals = method =>
method.Body.Variables.Any(v => v.Type.FullName.Contains("System.IO.MemoryStream")) &&
method.Body.Variables.Any(v => v.Type.FullName.Contains("System.Security.Cryptography.CryptoStream")) &&
method.Body.Variables.Any(v => v.Type.FullName.Contains("System.Security.Cryptography.ICryptoTransform"));

Func<MethodDef, bool> hasCryptoStreamCtor = method =>
method.Body.Instructions.Any(i =>
i.OpCode == OpCodes.Newobj &&
i.Operand is IMethod ctor &&
ctor.DeclaringType.FullName == "System.Security.Cryptography.CryptoStream");

Func<MethodDef, bool> hasCryptoStreamHelpers = method =>
method.Body.Instructions
.Where(i => i.OpCode == OpCodes.Call)
.Select(i => i.Operand as IMethod)
.Where(md => md != null)
.Any(md =>
md.MethodSig.Params.Any(p =>
p.FullName == "System.Security.Cryptography.CryptoStream" ||
p.FullName == "System.Security.Cryptography.CipherMode"));

Func<MethodDef, bool> isKnownDecrypter = method =>
EncryptedResource.IsKnownDecrypter(method, Array.Empty<string>(), true);

Func<MethodDef, bool> isDecrypterMethod = method =>
method.IsStatic &&
method.HasBody &&
method.Body.HasInstructions &&
hasRequiredLocals(method) &&
hasCryptoStreamCtor(method) &&
hasCryptoStreamHelpers(method) &&
isKnownDecrypter(method);

foreach (var methodDef in Context.Module.GetTypes()
.SelectMany(t => t.Methods)
.Where(isDecrypterMethod))
{
_encryptedResource = new EncryptedResource(Context, methodDef);

if (_encryptedResource.EmbeddedResource != null)
return true;

_encryptedResource.Dispose();
}
return false;
}

private bool FindBinaryReaderMethod(out int popCallsCount)
{
popCallsCount = 0;
Expand Down