Cabals packet is time stamped. Meaning, everytime you tried to manipulate/edit/forge a packet and send back to server. The server won't recognize that. Instead, it will reply a Disconnection packet back to the client.
Old games such as MU Online, Ragnarok is poor at these packet protection method. New games like Silkroad or similar is now time stamped.
I have read how to bypass time-stamped packets, but Im not sure if the site is still available.