HackTrick

Newbie note:

Lots of people email me asking how to learn what their user name
and password are. Stop laughing, darn it, they really do. If you don't know your
user name and password, that means whoever runs that computer didn't give you an
account and doesn't want you to log on.


Then comes the message:

Password:

Again, be exact in typing in your password.

What if this doesn't work?

Every day people write to me complaining they can't telnet. That is usually
because they try to telnet into a computer, or a port on a computer that is set
up to refuse telnet connections. Here's what it might look like when a computer
refuses a telnet connection:

C:\ >telnet 10.0.0.3
Connecting To 10.0.0.3...Could not open connection to the host, on port 23. A
connection attempt failed because the connected party did not properly respond
after a period of time, or established connection failed because connected host
has failed to respond.

Or you might see:

C:\ >telnet hotmail.com
Connecting To hotmail.com...Could not open connection to the host, on port
23. No connection could be made because the target machine actively refused it.

If you just give the telnet command without giving a port number, it will
automatically try to connect on port 23, which sometimes runs a telnet server.


note: your Windows computer has a telnet client program, meaning it will
let you telnet out of it. However you have to install a telnet server before
anyone can telnet into port 23 on your computer.


If telnet failed to connect, possibly the computer you were trying to telnet
into was down or just plain no longer in existence. Maybe the people who run
that computer don't want you to telnet into it.

Even though you can't telnet into an account inside some computer, often you can
get some information back or get that computer to do something interesting for
you. Yes, you can get a telnet connection to succeed -without doing anything
illegal --against almost any computer, even if you don't have permission to log
in. There are many legal things you can do to many randomly chosen computers
with telnet. For example:

C:/telnet freeshell.org 22

SSH-1.99-OpenSSH_3.4p1

That tells us the target computer is running an SSH server, which enables
encrypted connections between computers. If you want to SSH into an account
there, you can get a shell account for free at http://freeshell.org . You can
get a free SSH client program from http://winfiles.com .


***************
You can get punched in the nose warning: Your online provider might kick you off
for making telnet probes of other computers. The solution is to get a local
online provider and make friends with the people who run it, and convince them
you are just doing harmless, legal explorations.
*************

Sometimes a port is running an interesting program, but a firewall won't let you
in. For example, 10.0.0.3, a computer on my local area network, runs an email
sending program, (sendmail working together with Postfix, and using Kmail to
compose emails). I can use it from an account inside 10.0.0.3 to send emails
with headers that hide from where I send things.

If I try to telnet to this email program from outside this computer, here's what
happens:

C:\>telnet 10.0.0.3 25
Connecting To 10.0.0.3...Could not open connection to the host, on port 25. No
connection could be made because the target machine actively refused it.

However, if I log into an account on 10.0.0.3 and then telnet from inside to
port 25, here's what I get:

Last login: Fri Oct 18 13:56:58 2002 from 10.0.0.1
Have a lot of fun...
cmeinel@test-box:~> telnet localhost 25
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1... [Carolyn's note: 127.0.0.1 is the numerical address meaning
localhost, the same computer you are logged into]
Connected to localhost.
Escape character is '^]'.
220 test-box.local ESMTP Postfix

The reason I keep this port 25 hidden behind a firewall is to keep people from
using it to try to break in or to forge email. Now the ubergeniuses reading this
will start to make fun of me because no Internet address that begins with 10. is
reachable from the Internet. However, sometimes I place this "test-box" computer
online with a static Internet address, meaning whenever it is on the Internet,
it always has the same numerical address. I'm not going to tell you what its
Internet address is because I don't want anyone messing with it. I just want to
mess with other people's computers with it, muhahaha. That's also why I always
keep my Internet address from showing up in the headers of my emails.