UltraVNC

The awnser is in my reply to monchhichi.. The old SC is hard coded with this function, I use the newest standard vncviewer.exe and this version doesn't have the "confirmation dialog box" coded into it.. I only coded a "launcher" to run/execute the vncviewer.exe with -parameters.. I hope this is ...

... it will be lovely if there is an option for the viewer to accept or reject the SC connection. Just like the original does.
@monchhichi , You can right click the vncviewer icon and select "toggle listen mode off". This will reject any new made connections... The function you are asking for is ...