How to detect if a running Windows application is being accessed remotely?

Hi Experts,

I am looking for a way to detect if my running vb.net Windows Forms application is being accessed remotely via software such as Remote Desktop, VNC, Teamviewer etc.

Regards,
Leigh
LVL 1
LeighWardleAsked:
Who is Participating?
 
SAMIR BHOGAYTAConnect With a Mentor Freelancer and IT ConsultantCommented:
hi... Try this

using System.Runtime.InteropServices;


 public class RemoteSessionChecker
  {
    /// <summary>
    /// Checks whether the current user is is logged in through a remote session
    /// </summary>
    /// <returns></returns>
    public static bool Check()
    {
      bool IsRemoteSession = false;
      //Constant used to check for remote sessions
      const int SM_REMOTESESSION = 0x2001;
      //This function will return 0 if the session is local
      int Value = GetSystemMetrics(SM_REMOTESESSION);

      IsRemoteSession = (Value != 0);

      return IsRemoteSession;
    }

    [DllImport("user32.dll", EntryPoint = ("GetSystemMetrics"))]
    private static extern int GetSystemMetrics(int nIndex);
  }
0
 
chaauCommented:
There is a Win32 API that is designed for this:
GetSystemMetrics(SM_REMOTESESSION);

Open in new window

When the program running in a remote desktop session the API will return not zero value.
Please check this web-site how to call this API via PInvoke:
Public Declare Auto Function GetSystemMetrics Lib "user32.dll" (ByVal smIndex As Integer) As Integer

Open in new window

0
 
LeighWardleAuthor Commented:
Hi samirbhogayta,  thanks for your suggestion.

I am not a c## developer, so I converted your code to vb.net:

Imports System.Runtime.InteropServices

Public Class RemoteSessionChecker
	''' <summary>
	''' Checks whether the current user is is logged in through a remote session
	''' </summary>
	''' <returns></returns>
	Public Shared Function Check() As Boolean
		Dim IsRemoteSession As Boolean = False
		'Constant used to check for remote sessions
		Const  SM_REMOTESESSION As Integer = &H2001
		'This function will return 0 if the session is local
		Dim Value As Integer = GetSystemMetrics(SM_REMOTESESSION)

		IsRemoteSession = (Value <> 0)

		Return IsRemoteSession
	End Function

	<DllImport("user32.dll", EntryPoint := ("GetSystemMetrics"))> _
	Private Shared Function GetSystemMetrics(nIndex As Integer) As Integer
	End Function
End Class

'=======================================================
'Service provided by Telerik (www.telerik.com)
'Conversion powered by NRefactory.
'Twitter: @telerik
'Facebook: facebook.com/telerik
'=======================================================

Open in new window


But the function always returns False - even when I am connected by RDP.

Regards,
Leigh
0
The new generation of project management tools

With monday.com’s project management tool, you can see what everyone on your team is working in a single glance. Its intuitive dashboards are customizable, so you can create systems that work for you.

 
chaauConnect With a Mentor Commented:
SM_REMOTESESSION value is 0x1000, or converting to VB it is &H1000
0
 
LeighWardleAuthor Commented:
Thanks, chaau.

Changing SM_REMOTESESSION value (for VB) to &H1000 now makes the code detect if it is connected by RDP.
That's the good news.

The bad news is that it does not detect if it is connected via TeamViewer.  (I haven't tried VNC or anything else).
0
 
chaauCommented:
Teamviewer, Logmein and such technically do not work via RDP, but connect to the user session. They cannot be detected via SM_REMOTESESSION. You will need to test if processes associated with these services are running using CreateToolhelp32Snapshot() API.
0
All Courses

From novice to tech pro — start learning today.