-- Tested on macOS 10.13.6

use AppleScript version "2.4"
use scripting additions

using terms from application "Mail"
	on perform mail action with messages messageList in mailboxes mbox for rule aRule
		
		--	Save on DesktopPath 	
		set desktopPath to (path to desktop) as string
		
		tell application "Mail"
			set selectedMessages to the selection
			repeat with aMessage in selectedMessages
				repeat with anAttachment in mail attachments of aMessage
					set attachmentName to name of anAttachment
					save anAttachment in file (desktopPath & attachmentName)
					
				end repeat
			end repeat
		end tell
		
	end perform mail action with messages
end using terms from