Difference between pages "ProDiscovery" and "Email Headers"

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'''Email Headers''' are lines of [[metadata]] attached to each [[email]] that contain lots of useful information for a [[forensic investigator]]. However, email headers can be easily forged, so they should never be used as the only source of information.
  
=ProDiscovery=  
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== Making Sense of Headers ==
  
This tool from Tech Pathways will gather data from most major file systems and perform some analysis.
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There is no single way to make sense of email headers. Some examiners favor reading from the bottom up, some favor reading from the top down. Because information in the headers can be put there by the user's [[Mail User Agent|MUA]], a server in transit, or the recipient's [[Mail User Agent|MUA]], it can be difficult to determine when a line was added.
  
[http://www.techpathways.com/ProDiscoverDFT.htm website]
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=== Mail User Agents ===
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{{main|List of MUA Header Formats}}
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Every [[Mail User Agent|MUA]] sets up the headers for a message slightly differently. Although some headers are required under the applicable [http://www.faqs.org/rfcs/rfc2822.html RFC], their format and ordering can vary by client. Almost all clients, however, add their headers in a fixed format and order.
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The examiner can use the format and order for each client to show that messages were forged, but not that they were legitimate. For example, if a message purports to be from [[Apple Mail]] but the order or the headers do not match the [[Apple Mail Header Format]], the message has been forged. If the headers of the message do match that format, however, it does not guarantee that the message was sent by that program.
  
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=== Servers in Transit ===
  
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Mail servers can add lines onto email headers, usually in the form of "Received" lines, like this:
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<pre>Received: by servername.recipeienthost.com (Postfix, from userid 506)
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id 77C30808A; Sat, 24 Feb 2007 20:43:56 -0500 (EST)</pre>
  
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== Message Id Field ==
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{{main|Using message id headers to determine if an email has been forged}}According to the current guidelines for email [http://www.faqs.org/rfcs/rfc2822.html], every message should have a Message-ID field. These id fields can be used to determine if a message has been forged. It is harder, but sometimes possible, to show that a message is authentic using the message id field. Where known, the Message-ID algorithms for known programs are [[List of MUA Header Formats|given on the separate pages for those programs]].
  
=Features=
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== Signature Fields ==
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{{main|Using signature headers to determine if an email has been forged}}Some email programs allow users to sign messages. This gives the recipient some assurance that the sender given in the message really sent the message. Obviously these headers can be used by an examiner for the same purpose.
  
==File Systems Understood==
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== Sample Header ==  
  
* FAT12, FAT16, FAT32
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This is an (incomplete) excerpt from an email header:
* NTFS
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* Solaris UFS
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* Linux ext2/ext3
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==File Search Facilities==
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Received: from lists.securityfocus.com (lists.securityfocus.com [205.206.231.19])
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        by outgoing2.securityfocus.com (Postfix) with QMQP
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        id 7E9971460C9; Mon,  9 Jan 2006 08:01:36 -0700 (MST)
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Mailing-List: contact forensics-help@securityfocus.com; run by ezmlm
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Precedence: bulk
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List-Id: <forensics.list-id.securityfocus.com>
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List-Post: <mailto:forensics@securityfocus.com>
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List-Help: <mailto:forensics-help@securityfocus.com>
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List-Unsubscribe: <mailto:forensics-unsubscribe@securityfocus.com>
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List-Subscribe: <mailto:forensics-subscribe@securityfocus.com>
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Delivered-To: mailing list forensics@securityfocus.com
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Delivered-To: moderator for forensics@securityfocus.com
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Received: (qmail 20564 invoked from network); 5 Jan 2006 16:11:57 -0000
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From: YJesus <yjesus@security-projects.com>
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To: forensics@securityfocus.com
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Subject: New Tool : Unhide
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User-Agent: KMail/1.9
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MIME-Version: 1.0
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Content-Disposition: inline
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Date: Thu, 5 Jan 2006 16:41:30 +0100
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Content-Type: text/plain;
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  charset="iso-8859-1"
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Content-Transfer-Encoding: quoted-printable
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Message-Id: <200601051641.31830.yjesus@security-projects.com>
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X-HE-Spam-Level: /
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X-HE-Spam-Score: 0.0
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X-HE-Virus-Scanned: yes
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Status: RO
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Content-Length: 586
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Lines: 26
  
* Uses a set of Perl scrypts.
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== External Links ==
 
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* [http://en.wikipedia.org/wiki/Computer_forensics#E-mail_Headers Wikipedia entry on email headers]
==Historical Reconstruction==
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Can it build timelines and search by creation date?
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==Searching Abilities==
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Can it search? Does it build an index? Can it focus on file types or particular kinds of metadata?
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==Hash Databases==
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Can it create hashes of files and/or blocks? Can it compare these hash values to any databases?
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What sort of hash functions does it use?
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==Evidence Collection Features==
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* Generates an XML-based report about the analysis.
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=History=
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==License Notes==
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Commercial.
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= External Links =
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[http://www.techpathways.com/ProDiscoverDFT.htm website]
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==External Reviews==
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Revision as of 08:32, 18 June 2007

Email Headers are lines of metadata attached to each email that contain lots of useful information for a forensic investigator. However, email headers can be easily forged, so they should never be used as the only source of information.

Making Sense of Headers

There is no single way to make sense of email headers. Some examiners favor reading from the bottom up, some favor reading from the top down. Because information in the headers can be put there by the user's MUA, a server in transit, or the recipient's MUA, it can be difficult to determine when a line was added.

Mail User Agents

Every MUA sets up the headers for a message slightly differently. Although some headers are required under the applicable RFC, their format and ordering can vary by client. Almost all clients, however, add their headers in a fixed format and order. The examiner can use the format and order for each client to show that messages were forged, but not that they were legitimate. For example, if a message purports to be from Apple Mail but the order or the headers do not match the Apple Mail Header Format, the message has been forged. If the headers of the message do match that format, however, it does not guarantee that the message was sent by that program.

Servers in Transit

Mail servers can add lines onto email headers, usually in the form of "Received" lines, like this:

Received: by servername.recipeienthost.com (Postfix, from userid 506)
	id 77C30808A; Sat, 24 Feb 2007 20:43:56 -0500 (EST)

Message Id Field

Main article Using message id headers to determine if an email has been forgedAccording to the current guidelines for email [1], every message should have a Message-ID field. These id fields can be used to determine if a message has been forged. It is harder, but sometimes possible, to show that a message is authentic using the message id field. Where known, the Message-ID algorithms for known programs are given on the separate pages for those programs.

Signature Fields

Main article Using signature headers to determine if an email has been forgedSome email programs allow users to sign messages. This gives the recipient some assurance that the sender given in the message really sent the message. Obviously these headers can be used by an examiner for the same purpose.

Sample Header

This is an (incomplete) excerpt from an email header:

Received: from lists.securityfocus.com (lists.securityfocus.com [205.206.231.19])
        by outgoing2.securityfocus.com (Postfix) with QMQP
        id 7E9971460C9; Mon,  9 Jan 2006 08:01:36 -0700 (MST)
Mailing-List: contact forensics-help@securityfocus.com; run by ezmlm
Precedence: bulk
List-Id: <forensics.list-id.securityfocus.com>
List-Post: <mailto:forensics@securityfocus.com>
List-Help: <mailto:forensics-help@securityfocus.com>
List-Unsubscribe: <mailto:forensics-unsubscribe@securityfocus.com>
List-Subscribe: <mailto:forensics-subscribe@securityfocus.com>
Delivered-To: mailing list forensics@securityfocus.com
Delivered-To: moderator for forensics@securityfocus.com
Received: (qmail 20564 invoked from network); 5 Jan 2006 16:11:57 -0000
From: YJesus <yjesus@security-projects.com>
To: forensics@securityfocus.com
Subject: New Tool : Unhide
User-Agent: KMail/1.9
MIME-Version: 1.0
Content-Disposition: inline
Date: Thu, 5 Jan 2006 16:41:30 +0100
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Message-Id: <200601051641.31830.yjesus@security-projects.com>
X-HE-Spam-Level: /
X-HE-Spam-Score: 0.0
X-HE-Virus-Scanned: yes
Status: RO
Content-Length: 586
Lines: 26

External Links