Hacking VAXs & Unix by the Jolly Roger
Unix is a trademark of At&t (and you know what that means)
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In this article, we discuss the unix system that runs on
the various vax systems. If you are on another unix-type system, some
commands may differ, but since it is licenced to bell, they can't make many
changes.
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Hacking onto a unix system is very difficult, and in this case, we advise
having an inside source, if possible. The reason it is difficult to hack a
vax is this: Many vax, after you get a carrier from them, respond=>
Login:
They give you no chance to see what the login name format is. Most commonly
used are single words, under 8 digits, usually the person's name. There is
a way around this: Most vax have an acct. called 'suggest' for people to
use to make a suggestion to the system root terminal. This is usually watched
by the system operator, but at late he is probably at home sleeping or
screwing someone's brains out. So we can write a program to send at the
vax this type of a message:
A screen freeze (Cntrl-s), screen clear (system dependant), about 255
garbage characters, and then a command to create a login acct., after which
you clear the screen again, then unfreeze the terminal. What this does:
When the terminal is frozen, it keeps a buffer of what is sent. well, the
buffer is about 127 characters long. so you overflow it with trash, and then
you send a command line to create an acct. (System dependant). after this
you clear the buffer and screen again, then unfreeze the terminal. This is
a bad way to do it, and it is much nicer if you just send a command to
the terminal to shut the system down, or whatever you are after...
There is always, *Always* an acct. called root, the most powerful acct.
to be on, since it has all of the system files on it. If you hack your
way onto this one, then everything is easy from here on...
On the unix system, the abort key is the Cntrl-d key. watch how many times
you hit this, since it is also a way to log off the system!
A little about unix architechture: The root directory, called root, is
where the system resides. After this come a few 'sub' root directories,
usually to group things (stats here, priv stuff here, the user log here...).
Under this comes the superuser (the operator of the system), and then
finally the normal users. In the unix 'Shell' everything is treated the same.
By this we mean: You can access a program the same way you access a user
directory, and so on. The way the unix system was written, everything,
users included, are just programs belonging to the root directory. Those
of you who hacked onto the root, smile, since you can screw everything...
the main level (exec level) prompt on the unix system is the $, and if you
are on the root, you have a # (superuser prompt).
Ok, a few basics for the system... To see where you are, and what paths
are active in regards to your user account, then type
=> pwd
This shows your acct. seperated by a slash with another pathname (acct.),
possibly many times. To connect through to another path,
or many paths, you would type:
You=> path1/path2/path3
and then you are connected all the way from path1 to path3. You can
run the programs on all the paths you are connected to. If it does
not allow you to connect to a path, then you have insufficient privs, or
the path is closed and archived onto tape. You can run programs this way
also:
you=> path1/path2/path3/program-name
Unix treats everything as a program, and thus there a few commands to
learn...
To see what you have access to in the end path, type=>
ls
for list. this show the programs you can run. You can connect to
the root directory and run it's programs with=>
/root
By the way, most unix systems have their log file on the root, so you
can set up a watch on the file, waiting for people to log in and snatch their
password as it passes thru the file. To connect to a directory, use the
command:
=> cd pathname This allows you to do what you want
with that directory. You may be asked for a password, but this is a good
ay of finding other user names to hack onto.
The wildcard character in unix, if you want to search down a path for
a game or such, is the *.
=> ls /*
Should show you what you can access. The file types are the same as they
are on a dec, so refer to that section when examining file. To see what is
in a file, use the
=> pr
filename command, for print file.
We advise playing with pathnames to get the hang of the concept. There
is on-line help available on most systems with a 'help' or a '?'.
We advise you look thru the help files and pay attention to anything
they give you on pathnames, or the commands for the system.
You can, as a user, create or destroy directories on the tree beneath you.
This means that root can kill everything but root, and you can kill any
that are below you. These are the
=> mkdir pathname
=> rmdir pathname
commands.
Once again, you are not alone on the system... type=>
who
to see what other users are logged in to the system at the time. If you
want to talk to them=>
write username
Will allow you to chat at the same time, without having to worry
about the parser. To send mail to a user, say
And enter the mail sub-system. To send a message to all the users
on the system, say
=> wall
Which stands for 'write all'. By the way, on a few systems,
all you have to do is hit the <return> key to end the message,
but on others you must hit the cntrl-d key.
To send a single message to a user, say
=> write username
this is very handy again! If you send the sequence of characters discussed
at the very beginning of this article, you can have the super-user terminal do
tricks for you again.
Privs:
If you want superuser privs, you can either log in as root, or edit your
acct. so it can say
=> su
this now gives you the # prompt, and allows you to completely by-pass the
protection. The wonderful security conscious developers at bell made it
very difficult to do much without privs, but once you have them, there
is absolutely nothing stopping you from doing anything you want to.
To bring down a unix system:
=> chdir /bin
=> rm *
this wipes out the pathname bin, where all the system maintenance files are.
Or try:
=> r -r
This recursively removes everything from the system except the remove
command itself.
Or try:
=> kill -1,1
=> sync
This wipes out the system devices from operation.
When you are finally sick and tired from hacking on the vax systems, just
hit your cntrl-d and repeat key, and you will eventually be logged out.
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The reason this file seems to be very sketchy is the fact that bell has 7
licenced versions of unix out in the public domain, and these commands are
those common to all of them. I recommend you hack onto the root or
bin directory, since they have the highest levels of privs, and there
is really not much you can do (except develop software) without them.
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