VB.Net Signature:

Private Declare Function IsDebuggerPresent Lib "kernel32" () As Integer

C# Signature:

[DllImport("kernel32.dll")]
static extern bool IsDebuggerPresent();

Boo Signature:

[DllImport("kernel32.dll", SetLastError : true)]
def IsDebuggerPresent() as bool:
     pass

User-Defined Types:

None.

VB Usage:

Boo Signature:

[DllImport("kernel32.dll", SetLastError : true)]
def IsDebuggerPresent() as bool:
     pass

Private Declare Function IsDebuggerPresent Lib "kernel32" () As Integer

User-Defined Types:

None.

  Try

VB Usage:

        If IsDebuggerPresent = 1 Then

Private Declare Function IsDebuggerPresent Lib "kernel32" () As Integer

        MsgBox("Debugger is present!") 'Debugger was detected
  Try

        Else
        If IsDebuggerPresent = 1 Then

        MsgBox("Debugger isn't present!") Debugger was not detected
        MsgBox("Debugger is present!") 'Debugger was detected

        End If
        Else

    Catch ex As Exception
        MsgBox("Debugger isn't present!") Debugger was not detected

        MsgBox(ex.Message)
        End If

    End Try
    Catch ex As Exception

Notes:

This is a quick way to help protect your applications from being reverse engineered at runtime. Call this when your application starts and exit if it returns true.

        MsgBox(ex.Message)

Tips & Tricks:

Call this before your application starts to protect it from runtime analysis. This is a weak form of protection, and is trivially bypassed. For a more robust mechanism, use a .NET obfuscator tool.

    End Try

Sample Code:

Notes:

This is a quick way to help protect your applications from being reverse engineered at runtime. Call this when your application starts and exit if it returns true.

// debug checking in debug builds would make it impossible to debug in Visual Studio
#if !DEBUG
   if (IsDebuggerPresent() == true) {
      Application.Exit();
   }
#endif

Alternative Managed API:

Do you know one? Please contribute it!

Tips & Tricks:

Call this before your application starts to protect it from runtime analysis. This is a weak form of protection, and is trivially bypassed. For a more robust mechanism, use a .NET obfuscator tool.

Sample Code:

// debug checking in debug builds would make it impossible to debug in Visual Studio
#if !DEBUG
   if (IsDebuggerPresent() == true) {
      Application.Exit();
   }
#endif

Alternative Managed API:

Do you know one? Please contribute it!

Please edit this page!

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• helpful tips or sample code to share for using this API in managed code?
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