In PuTTY, right-click on the mouse is configured to automatically pastes the contents from the clip-board. While this is a great convenience, it is equally dangerous when you are logged onto live production systems. Have you pasted “reboot” and pressed enter without realizing what you’ve done??
The following procedure will help you change this default behaviour to prompt to paste than pasting automatically when you right-click.
1. Open PuTTY, in the left-pane, click Selection under Window.
2. In the right-pane select the radio button for “Windows (Middle extends, Right brings up menu)”.
3. Click Session in the left pane, select “Default Settings” and click Save.
Now, for every saved session, select and load and follow the above (in step3, instead of default session, choose your saved session).
If you want to enable it back, follow the procedure and in step 3, choose radio button for “Compromise (Middle Extends, Right Pastes)”.