Secure Your Application Using .NET Reactor

It is a very simple tool you can secure your applications developed in .NET.

You can find the below link to download.

After downloading install it.

Create a console application to test it. Say for example you have only one line of code which has “Console.WriteLine(“Testing Refractor”)” and then compile the program in release mode. After that browse the application folder\bin you will see [applicationname].exe.

Go to Visual Studio Command Prompt and type

ildasm C:\Projects\TestApp\bin\Release\TestApp.exe /output:C:\Temp\

after typing this press enter.

A file with name will get created in “C:\Temp”

If you open the in notepad you may find the below code you have entered.

// =============== CLASS MEMBERS DECLARATION ===================

.class private auto ansi beforefieldinit ConsoleApplicationReactorTest.Program
extends [mscorlib]System.Object
.method private hidebysig static void Main(string[] args) cil managed
// Code size 11 (0xb)
.maxstack 8
IL_0000: ldstr “Testing Reactor”
IL_0005: call void [mscorlib]System.Console::WriteLine(string)
IL_000a: ret
} // end of method Program::Main

.method public hidebysig specialname rtspecialname
instance void .ctor() cil managed
// Code size 7 (0x7)
.maxstack 8
IL_0000: ldarg.0
IL_0001: call instance void [mscorlib]System.Object::.ctor()
IL_0006: ret
} // end of method Program::.ctor

} // end of class ConsoleApplicationReactorTest.Program
// =============================================================

You can see the code which is bold.

If any passwords used to connect the database is stored then you will be in a big trouble so it can be easily hacked.

To overcome this burden open the .Net Reactor installed.

It will loads the Create Project page and upload your application exe/dll in the Main Assembly and click protect in the left side pane. Before doing that make sure that you have checked whatever functionality you need in the check box shown at the bottom.



After clicking protect page you will get the following results as shown in the screen below,


It will create an exe file in your application folder\bin\release\TestApp_Secure\TestApp.exe

.NET Reactor creates a secured exe/dll with the Application Folder with “_Secure” suffixed. The size of exe will be bit large when compared to the original exe.

If you try to de compile the exe it will give error.

Let us check that by giving the following lines of code in VS Command Prompt.

ildasm C:\Projects\TestApp\bin\Release\TestApp_Secure\TestApp.exe /output:C:\Temp\

it will gives the following output in the file

// Microsoft (R) .NET Framework IL Disassembler. Version 3.5.21022.8
// Copyright (c) Microsoft Corporation. All rights reserved.

Protected module — cannot disassemble


Thus you dll/exe protected being hacked.

Copy this dll exe to your webserver or pc to get the work done.

Apart from this you can create your own license by using this tool. 🙂


Happy Coding !!! 🙂






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