Tunneling through ICMP

Some cellular network providers bill only TCP/UDP traffic but pay no attention to ICMP. This means that the hacker can organize an ICMP tunnel, in which case data transmission will become free. No one would be able to blame you, because you are a legal user and you have the right to use all services provided by your service provider in any way as long as you do not violate the law. Thus, the service provider has no formal right to prosecute you. The only thing that it can do is to refuse to provide you services any longer, so do not use this approach too excessively and do not transmit hundreds of gigabytes of traffic.

All that the hacker needs to do to establish an ICMP tunnel is to install an ICMP shell. The server component must be installed at the desktop computer, and the client part must be installed on the mobile computer (you can use any hosting service instead of the desktop computer with a DSL connection). There are lots of such ICMP shells . In my opinion, the best is the implementation by Peter Kieltyk, distributed in source code. This is a standard command-line shell; however, it can be easily extended to an HTTP proxy server (it is necessary to do this on your own), after which you'll be able to surf the mobile Internet using either Firefox or Internet Explorer. The eMule client also will work (although only with lowID). Naturally, there is no such thing as an absolutely free mobile Internet in this case, because no hosting service provider would allow anyone to have unlimited traffic just for a few dollars. Thus, don't think that you'd be allowed to download movies for free.

An ICMP tunnel provides a considerably lower quality of service than TCP/IP connections. Slow and frequently terminating connections occur often. All these circumstances can make a hacker nervous and take lots of time. Nevertheless, all these drawbacks are balanced by the advantage of cheap traffic.

Hacker Software

• SSHWindows. Freeware console SSH/SFTP client and server for the Windows platform. Download it from http://sshwindows. sourceforge .net .

• Secure iXplorer GPL. Freeware graphical SSH/SFTP client with the Total Commander interface, intended for the Windows platform. Available at http://www.i-tree.org/gpl/ixplorer.htm .

• WinSCP. Freeware SFTP plug-in for FAR Manager. Download it from http://winscp.net/eng/index.php .

• ICMP shell. Freeware ICMP shell (Fig. 30.6) operating under UNIX. Download it from http://icmpshell.sourceforge.net .

Figure 30.6: WinSCP freeware shell for UNIX