RatHole is a unix backdoor which compiles cleanly on standard Linux and OpenBSD (probably other BSD flavors also) without additional libraries. It features blowfish encryption, process name hiding and definition of a preferred shell. It spits no error messages (like for sockets already bound) because it is supposed to be stealth. When a client connects to the backdoor a new shell process and two pipe files are created. The I/O of the shell is duped to the pipes and the daemon encrypts the communication.
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