Here's a script to punch a big hole thru your VPS's security and access your shell over Telegram chat… don't try this on production.

ohgodno.lua

-- To use: telegram-cli -k tg-server.pub -s ohgodno.lua
--
-- Remember to watch for your telegram ID in telegram-cli, update it below.
-- This script will let you message yourself, and will ignore messages from others.

telegram_id = 1234567
message_echo = ""

function on_msg_receive (msg)
    if msg.to.id == telegram_id and msg.from.id == telegram_id and msg.text ~= message_echo then
        text = execute_command(msg.text)
        message_echo = text
        send_msg (msg.from.print_name, text, ok_callback, false)
    end
end

function execute_command (command)
	local execute  = io.popen(command..' 2>&1')
	local result = execute:read("*a")
	execute:close()
	return result
end

function ok_callback ()    
end

telegram-cli is here: https://github.com/vysheng/tg