Firepass

Firewallをバイパスするトンネリングツールです。

Firepass is a tunneling tool, allowing bypassing of firewall restrictions and encapsulation of data flows inside legal ones (by using HTTP POST requests). Any TCP or UDP based protocols may be tunneled with Firepass.
For now, both - client and server parts are written in Perl and the server script acts as a CGI program.

Web Shell(Wsh)というのもここにありますね。