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The Basics of Hacking II: Vax's Unix · Article

Unix is a trademark of bell labs (and you know what that means)

Welcome to the basics of hacking ii: vax's and unix.

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.

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 un- freeze 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 # (super- user prompt).

Ok, a few basics for the system... To see where you are, and what paths are active in reguards to your user account, then type
=> pwd

This shows your acct. Seperated by a slash with an other 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 i t'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 way 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 r efer 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 attent ion 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
=> mail

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 super-user 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 repe at key, and you will eventually be logged out. 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. Were commend 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 develope software) without them.

Next to come: the basics of hacking iii: data general

This article written by: the knights of shadow
[end] 1984
Posted By Gremelin Posted on October 21st, 2009 · Updated on December 31st, 2010
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