HackTrick

Want a computer you can telnet into and mess around with, and not get into
trouble no matter what you do to it? I've set up my techbroker.com
(206.61.52.33) with user xyz, password guest for you to play with. Here's how to
forge email to xyz@techbroker.com using telnet. Start with the command:

C:\>telnet techbroker.com 25
Connecting To Techbroker.com

220 Service ready

Now you type in who you want the message to appear to come from:

helo santa@techbroker.com
Techbroker.com will answer:

250 host ready

Next type in your mail from address:

mail from:santa@techbroker.com

250 Requested mail action okay, completed

Your next command:

rcpt to:xyz@techbroker.com
250 Requested mail action okay, completed

Your next command:
data
354 Start main input; end with .


just means hit return. In case you can't see that little
period between the s, what you do to end composing your email is to hit
enter, type a period, then hit enter again. Anyhow, try typing:

This is a test.
.
250 Requested mail action okay, completed
quit
221 Service closing transmission channel

Connection to host lost.

Using techbroker's mail server, even if you enable full headers, the message we
just composed looks like:

Status: R
X-status: N

This is a test.

That's a pretty pathetic forged email, huh? No "from", no date. However, you can
make your headers better by using a trick with the data command. After you give
it, you can insert as many headers as you choose. The trick is easier to show
than explain:

220 Service ready
helo santa@northpole.org
250 host ready
mail from:santa@northpole.com
250 Requested mail action okay, completed
rcpt to:cmeinel@techbroker.com
250 Requested mail action okay, completed
data
354 Start main input; end with .
from:santa@deer.northpole.org
Date: Mon, 21 Oct 2002 10:09:16 -0500
Subject: Rudolf
This is a Santa test.
.
250 Requested mail action okay, completed
quit
221 Service closing transmission channel


Connection to host lost.

The message then looks like:

from:santa@deer.northpole.org
Date: Mon, 21 Oct 2002 10:09:16 -0500
Subject: Rudolf
This is a Santa test.

The trick is to start each line you want in the headers with one word followed
by a colon, and the a line followed by "return". As soon as you write a line
that doesn't begin this way, the rest of what you type goes into the body of the
email.

Notice that the santa@northpole.com from the "mail from:" command didn't show up
in the header. Some mail servers would show both "from" addresses.

You can forge email on techbroker.com within one strict limitation. Your email
has to go to someone at techbroker.com. If you can find any way to send email to
someone outside techbroker, let us know, because you will have broken our
security, muhahaha! Don't worry, you have my permission.

Next, you can read the email you forge on techbroker.com via telnet:

C:\>telnet techbroker.com 110

+OK <30961.5910984301@techbroker.com> service ready

Give this command:
user xyz
+OK user is known

Then type in this:
pass test
+OK mail drop has 2 message(s)

retr 1
+OK message follows
This is a test.

If you want to know all possible commands, give this command:

help
+OK help list follows
USER user
PASS password
STAT
LIST [message]
RETR message
DELE message
NOOP
RSET
QUIT
APOP user md5
TOP message lines
UIDL [message]
HELP

Unless you use a weird online provider like AOL, you can use these same tricks
to send and receive your own email. Or you can forge email to a friend by
telnetting to his or her online provider's email sending computer(s).

With most online providers you need to get the exact name of their email
computer(s). Often it is simply mail.targetcomputer.com (substitute the name of
the online provider for targetcomputer). If this doesn't work, you can find out
the name of their email server with the DOS nslookup program, which only runs
from cmd.exe. Here's an example:


C:\ >nslookup
Default Server: DNS1.wurld.net
Address: 206.61.52.11

> set q=mx
> dimensional.com
Server: DNS1.wurld.net
Address: 206.61.52.11

dimensional.com MX preference = 5, mail exchanger =
mail.dimensional.com
dimensional.com MX preference = 10, mail exchanger =
mx2.dimensional.com
dimensional.com MX preference = 20, mail exchanger =
mx3.dimensional.com
dimensional.com nameserver = ns.dimensional.com
dimensional.com nameserver = ns-1.dimensional.com
dimensional.com nameserver = ns-2.dimensional.com
dimensional.com nameserver = ns-3.dimensional.com
dimensional.com nameserver = ns-4.dimensional.com
mail.dimensional.com internet address = 206.124.0.11
mx2.dimensional.com internet address = 206.124.0.30
mx3.dimensional.com internet address = 209.98.32.54
ns.dimensional.com internet address = 206.124.0.10
ns.dimensional.com internet address = 206.124.26.254
ns.dimensional.com internet address = 206.124.0.254
ns.dimensional.com internet address = 206.124.1.254
ns.dimensional.com internet address = 209.98.32.54
ns.dimensional.com internet address = 206.124.0.32
ns.dimensional.com internet address = 206.124.0.30
ns.dimensional.com internet address = 206.124.0.25
ns.dimensional.com internet address = 206.124.0.15
ns.dimensional.com internet address = 206.124.0.21
ns.dimensional.com internet address = 206.124.0.9
ns-1.dimensional.com internet address = 206.124.26.254
ns-2.dimensional.com internet address = 209.98.32.54
ns-3.dimensional.com internet address = 206.124.1.254
ns-4.dimensional.com internet address = 206.124.0.254
>

The lines that tell you what computers will let you forge email to people with
@dimensional.com addresses are:

dimensional.com MX preference = 5, mail exchanger =
mail.dimensional.com
dimensional.com MX preference = 10, mail exchanger =
mx2.dimensional.com
dimensional.com MX preference = 20, mail exchanger =
mx3.dimensional.com

MX stands for mail exchange. The lower the preference number, the more they
would like you to use that address for email.If that lowest number server is too
busy, then try another server.

Sometimes when you ask about a mail server, nslookup will give you this kind of
error message:

DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
*** Request to [207.217.120.202] timed-out

To get around this problem, you need to find out what are the domain servers for
your target online provider. A good place to start looking is
http://netsol.com/cgi-bin/whois/whois . If this doesn't work, see
http://happyhacker.org/HHA/fightback.shtml for how to find the domain servers
for any Internet address.