The Hacker's Encyclopedia 1998/hackers_encyclopedia.iso/hacking/unix/unixhak1.txt

Text File | 2003-06-11 | 5.3 KB | 186 lines

*> Title:   Tutorial on hacking through a UNIX system


**

In the following file, all references
made to the name Unix, may also be
substituted to the Xenix operating
system.

Brief history:  Back in the early
sixties, during the development of
third generation computers at MIT,
a group of programmers studying the
potential of computers, discovered
their ability of performing two or
more tasks simultaneously.  Bell
Labs, taking notice of this discovery,
provided funds for their developmental
scientists to investigate into this
new frontier.  After about 2 years of
developmental research, they produced
an operating system they called "Unix".

Sixties to Current:  During this time
Bell Systems installed the Unix system
to provide their computer operators
with the ability to multitask so that
they could become more productive,
and efficient.  One of the systems they
put on the Unix system was called
"Elmos". Through Elmos many tasks (i.e.
billing,and installation records) could
be done by many people using the same
mainframe.

Note: Cosmos is accessed through the
Elmos system.

Current:  Today, with the development
of micro computers, such multitasking
can be achieved by a scaled down
version of Unix (but just as
powerful).  Microsoft,seeing this
development, opted to develop their own
Unix like system for the IBM line of
PC/XT's.  Their result they called
Xenix (pronounced zee-nicks).  Both
Unix and Xenix can be easily installed
on IBM PC's and offer the same function
(just 2 different vendors).

Note: Due to the many different
versions of Unix (Berkley Unix,
Bell System III, and System V
the most popular) many commands
following may/may not work. I have
written them in System V routines.
Unix/Xenix operating systems will
be considered identical systems below.

How to tell if/if not you are on a
Unix system:  Unix systems are quite
common systems across the country.
Their security appears as such:

Login;     (or login;)
password:

When hacking on a Unix system it is
best to use lowercase because the Unix
system commands are all done in lower-
case.
Login; is a 1-8 character field. It is
usually the name (i.e. joe or fred)
of the user, or initials (i.e. j.jones
or f.wilson).  Hints for login names
can be found trashing the location of
the dial-up (use your CN/A to find
where the computer is).
Password: is a 1-8 character password
assigned by the sysop or chosen by the
user.
      Common default logins
   --------------------------
   login;       Password:
   root         root,system,etc..
   sys          sys,system
   daemon       daemon
   uucp         uucp
   tty          tty
   test         test
   unix         unix
   bin          bin
   adm          adm
   who          who
   learn        learn
   uuhost       uuhost
   nuucp        nuucp

If you guess a login name and you are
not asked for a password, and have
accessed to the system, then you have
what is known as a non-gifted account.
If you guess a correct login and pass-
word, then you have a user account.
And, if you get the root p/w you have
a "super-user" account.
All Unix systems have the following
installed to their system:
root, sys, bin, daemon, uucp, adm
Once you are in the system, you will
get a prompt. Common prompts are:

$
%
#

But can be just about anything the
sysop or user wants it to be.

Things to do when you are in: Some
of the commands that you may want to
try follow below:

who is on  (shows who is currently
            logged on the system.)
write name (name is the person you
            wish to chat with)
      To exit chat mode try ctrl-D.
      EOT=End of Transfer.
ls -a      (list all files in current
            directory.)
du -a      (checks amount of memory
            your files use;disk usage)
cd\name    (name is the name of the
            sub-directory you choose)
cd\        (brings your home directory
            to current use)
cat name   (name is a filename either
            a program or documentation
            your username has written)
      Most Unix programs are written
      in the C language or Pascal
      since Unix is a programmers'
      environment.
One of the first things done on the
system is print up or capture (in a
buffer) the file containing all user
names and accounts. This can be done
by doing the following command:

cat /etc/passwd

If you are successful you will see a list
of all accounts on the system.  It
should look like this:

root:hvnsdcf:0:0:root dir:/:
joe:majdnfd:1:1:Joe Cool:/bin:/bin/joe
hal::1:2:Hal Smith:/bin:/bin/hal

Te "root" line tells the following
info :
login name=root
hvnsdcf   = encrypted password
0         = user group number
0         = user number
root dir  = name of user
/         = root directory

In the Joe login, the last part
"/bin/joe " tells us which directory
is his home directory (joe) is.

In the "hal" example the login name is
followed by 2 colons, that means that
there is no password needed to get in
using his name.

Conclusion:  I hope that this file
will help other novice Unix hackers
obtain access to the Unix/Xenix
systems that they may find.