Covert channeling via protocol benders deploy protocols in non-standard and perhaps nefarious ways. Contrasted with protocol benders, are covert channeling tools that use packet crafting to embed data in the actual packet headers, themselves. Covert_TCP and NUSHU are two such examples. Covert_TCP uses active channeling where it generates it is own packet train to create the channel. On the other hand, NUSHU is a passive channeler that piggybacks on packets transmitted to the TCP/IP stack by other applications. The covert effect is the same.
