Disabling clipboard (copy and paste) in NoMachine is possible by setting the appropriate key on the NoMachine server installation. It isn't restricted to the product you are using. I.e you can set it also if you have installed the free version of NoMachine on the computer you are accessing.
By default users can copy and paste from locale to the session and vice-versa.
You can configure the server to limit such operations by setting proper values in the server configuration file (/usr/NX/etc/server.cfg on Linux) as explained below.
Forbid copy & paste operations
To forbid copy & paste partially or totally, uncomment and set a proper value for the EnableClipboard key.
Possible settings are:
Content copied on the user's side can be pasted inside the session
Content copied inside the session can be pasted on the user's side
No copy and paste operations are allowed
Two-way copy and paste operations are allowed
Disabling device sharing services
NoMachine v. 6
NoMachine v. 5
NoMachine v. 4