Difference between pages "Research Topics" and "Carver 2.0 Planning Page"

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Interested in doing research in computer forensics? Looking for a master's topic, or just some ideas for a research paper? Here is our list. Please feel free to add your own ideas.
+
This page is for planning Carver 2.0.
  
Many of these would make a nice master's project.
+
Please, do not delete text (ideas) here. Use something like this:
  
=Programming Projects=
+
<pre>
 +
<s>bad idea</s>
 +
:: good idea
 +
</pre>
  
==Small-Sized Programming Projects==
+
This will look like:
* Modify [[bulk_extractor]] so that it can directly acquire a raw device under Windows. This requires replacing the current ''open'' function call with a ''CreateFile'' function call and using windows file handles.
+
* Rewrite SleuthKit '''sorter''' in C++ to make it faster and more flexible.
+
  
==Medium-Sized Programming Projects==
+
<s>bad idea</s>
* Create a program that visualizes the contents of a file, sort of like hexedit, but with other features:
+
:: good idea
** Automatically pull out the strings
+
** Show histogram
+
** Detect crypto and/or stenography.
+
* Extend [[fiwalk]] to report the NTFS alternative data streams.
+
* Create a method to detect NTFS-compressed cluster blocks on a disk (RAW data stream). A method could be to write a generic signature to detect the beginning of NTFS-compressed file segments on a disk. This method is useful in carving and scanning for textual strings.
+
* Write a FUSE-based mounter for SleuthKit, so that disk images can be forensically mounted using TSK.
+
* Modify SleuthKit's API so that the physical location on disk of compressed files can be learned.
+
  
 +
= License =
  
==Big Programming Projects==
+
BSD-3.
* Develop a new carver with a plug-in architecture and support for fragment reassembly carving (see [[Carver 2.0 Planning Page]]).
+
* Write a new timeline viewer that supports Logfile fusion (with offsets) and provides the ability to view the logfile in the frequency domain.
+
  
* Correlation Engine:
+
= OS =
** Logfile correlation
+
** Document identity identification
+
** Correlation between stored data and intercept data
+
** Online Social Network Analysis
+
  
* Find and download in a forensically secure manner all of the information in a social network (e.g. Facebook, LinkedIn, etc.) associated with a targeted individual.
+
Linux/FreeBSD/MacOS
** Determine who is searching for a targeted individual. This might be done with a honeypot, or documents with a tracking device in them, or some kind of covert Facebook App.
+
: (shouldn't this just match what the underlying afflib & sleuthkit cover? [[User:RB|RB]])
** Automated grouping/annotation of low-level events, e.g. access-time, log-file entry, to higher-level events, e.g. program start, login
+
:: Yes, but you need to test and validate on each. Question: Do we want to support windows? [[User:Simsong|Simsong]] 21:09, 30 October 2008 (UTC)
 +
:: [[User:Joachim Metz|Joachim]] I think we would do wise to design with windows support from the start this will improve the platform independence from the start
  
=Reverse-Engineering Projects=
+
= Requirements =
==Reverse-Engineering Projects==
+
=== Application analysis ===
+
* Reverse the on-disk structure of the [[Extensible Storage Engine (ESE) Database File (EDB) format]] to learn:
+
** Fill in the missing information about older ESE databases
+
** Exchange EDB (MAPI database), STM
+
** Active Directory (Active Directory working document available on request)
+
* Reverse the on-disk structure of the Lotus [[Notes Storage Facility (NSF)]]
+
* Reverse the on-disk structure of Microsoft SQL Server databases
+
  
=== Volume/File System analysis ===
+
* [[User:Joachim Metz|Joachim]] A name for the tooling I propose coldcut
* Analysis of inter snapshot changes in [[Windows Shadow Volumes]]
+
* Add support to SleuthKit for [[FAT|eXFAT]], Microsoft's new FAT file system.
+
* Add support to SleuthKit for [[Resilient File System (ReFS)|ReFS]].
+
* Modify SleuthKit's NTFS implementation to support NTFS encrypted files (EFS)
+
* Extend SleuthKit's implementation of NTFS to cover Transaction NTFS (TxF) (see [[NTFS]])
+
* Physical layer access to flash storage (requires reverse-engineering proprietary APIs for flash USB and SSD storage.)
+
  
==EnCase Enhancement==
+
[[User:Joachim Metz|Joachim]] Could we do a MoSCoW evaluation of these.
* Develop an EnScript that allows you to script EnCase from Python. (You can do this because EnScripts can run arbitrary DLLs. The EnScript calls the DLL. Each "return" from the DLL is a specific EnCase command to execute. The EnScript then re-enters the DLL.)
+
  
= Timeline analysis =
+
* AFF and EWF file images supported from scratch. ([[User:Joachim Metz|Joachim]] I would like to have raw/split raw and device access as well)
* Mapping differences and similarities in multiple versions of a system, e.g. those created by [[Windows Shadow Volumes]] but not limited to
+
* [[User:Joachim Metz|Joachim]] volume/partition aware layer (what about carving unpartioned space)
 +
* File system aware layer.
 +
** By default, files are not carved. (clarify: only identified? [[User:RB|RB]]; I guess that it operates like [[Selective file dumper]] [[User:.FUF|.FUF]] 07:00, 29 October 2008 (UTC))
 +
* Plug-in architecture for identification/validation.
 +
** [[User:Joachim Metz|Joachim]] support for multiple types of validators
 +
*** dedicated validator
 +
*** validator based on file library (i.e. we could specify/implement a file structure for these)
 +
*** configuration based validator (Can handle config files,like Revit07, to enter different file formats used by the carver.)
 +
* Ship with validators for:
 +
[[User:Joachim Metz|Joachim]] I think we should distinguish between file format validators and content validators
 +
** JPEG
 +
** PNG
 +
** GIF
 +
** MSOLE
 +
** ZIP
 +
** TAR (gz/bz2)
  
=Research Areas=
+
[[User:Joachim Metz|Joachim]] For a production carver we need at least the following formats
These are research areas that could easily grow into a PhD thesis.
+
** Grapical Images
* General-purpose detection of:
+
*** JPEG (the 3 different types with JFIF/EXIF support)
** Stegnography
+
*** PNG
** Sanitization attempts
+
*** GIF
** Evidence Falsification (perhaps through inconsistency in file system allocations, application data allocation, and log file analysis.
+
*** BMP
* Visualization of data/information in digital forensic context
+
*** TIFF
* SWOT of current visualization techniques in forensic tools; improvements; feasibility of 3D representation;
+
** Office documents
 +
*** OLE2 (Word/Excell content support)
 +
*** PDF
 +
*** Open Office/Office 2007 (ZIP+XML)
 +
** Archive files
 +
*** ZIP
 +
** E-mail files
 +
*** PFF (PST/OST)
 +
*** MBOX (text based format, base64 content support)
 +
** Audio/Video files
 +
*** MPEG
 +
*** MP2/MP3
 +
*** AVI
 +
*** ASF/WMV
 +
*** QuickTime
 +
** Printer spool files
 +
*** EMF (if I remember correctly)
 +
** Internet history files
 +
*** index.dat
 +
*** firefox (sqllite 3)
 +
** Other files
 +
*** thumbs.db
  
__NOTOC__
+
* Simple fragment recovery carving using gap carving.
 +
** [[User:Joachim Metz|Joachim]] have hook in for more advanced fragment recovery?
 +
* Recovering of individual ZIP sections and JPEG icons that are not sector aligned.
 +
** [[User:Joachim Metz|Joachim]] I would propose a generic fragment detection and recovery
 +
* Autonomous operation (some mode of operation should be completely non-interactive, requiring no human intervention to complete [[User:RB|RB]])
 +
** [[User:Joachim Metz|Joachim]] as much as possible, but allow to be overwritten by user
 +
* Tested on 500GB-sized images. Should be able to carve a 500GB image in roughly 50% longer than it takes to read the image.
 +
** Perhaps allocate a percentage budget per-validator (i.e. each validator adds N% to the carving time)
 +
** [[User:Joachim Metz|Joachim]] have multiple carving phases for precision/speed trade off?
 +
* Parallelizable
 +
** [[User:Joachim Metz|Joachim]] tunable for different architectures
 +
* Configuration:
 +
** Capability to parse some existing carvers' configuration files, either on-the-fly or as a one-way converter.
 +
** Disengage internal configuration structure from configuration files, create parsers that present the expected structure
 +
** [[User:Joachim Metz|Joachim]] The validator should deal with the file structure the carving algorithm should not know anything about the file structure (as in revit07 design)
 +
**  Either extend Scalpel/Foremost syntaxes for extended features or use a tertiary syntax ([[User:Joachim Metz|Joachim]] I would prefer a derivative of the revit07 configuration syntax which already has encountered some problems of dealing with defining file structure in a configuration file)
 +
* Can output audit.txt file.
 +
* [[User:Joachim Metz|Joachim]] Can output database with offset analysis values i.e. for visualization tooling
 +
* [[User:Joachim Metz|Joachim]] Can output debug log for debugging the algorithm/validation
 +
* Easy integration into ascription software.
 +
** [[User:Joachim Metz|Joachim]] I'm no native speaker what do you mean with "ascription software"?
  
[[Category:Research]]
+
= Ideas =
 +
* Use as much TSK if possible. Don't carry your own FS implementation the way photorec does.
 +
** [[User:Joachim Metz|Joachim]] using TSK as much as possible would not allow to add your own file system support (i.e. mobile phones, memory structures, cap files)
 +
I would propose wrapping TSK and using it as much as possible but allow to integrate own FS implementations.
 +
* Extracting/carving data from [[Thumbs.db]]? I've used [[foremost]] for it with some success. [[Vinetto]] has some critical bugs :( [[User:.FUF|.FUF]] 19:18, 28 October 2008 (UTC)
 +
* Carving data structures. For example, extract all TCP headers from image by defining TCP header structure and some fields (e.g. source port > 1024, dest port = 80). This will extract all data matching the pattern and write a file with other fields. Another example is carving INFO2 structures and URL activity records from index.dat [[User:.FUF|.FUF]] 20:51, 28 October 2008 (UTC)
 +
** This has the opportunity to be extended to the concept of "point at blob FOO and interpret it as BAR"
 +
 
 +
.FUF added:
 +
The main idea is to allow users to define structures, for example (in pascal-like form):
 +
 
 +
<pre>
 +
Field1: Byte = 123;
 +
SomeTextLength: DWORD;
 +
SomeText: string[SomeTextLength];
 +
Field4: Char = 'r';
 +
...
 +
</pre>
 +
 
 +
This will produce something like this:
 +
<pre>
 +
Field1 = 123
 +
SomeTextLength = 5
 +
SomeText = 'abcd1'
 +
Field4 = 'r'
 +
</pre>
 +
 
 +
(In text or raw forms.)
 +
 
 +
Opinions?
 +
 
 +
Opinion: Simple pattern identification like that may not suffice, I think Simson's original intent was not only to identify but to allow for validation routines (plugins, as the original wording was).  As such, the format syntax would need to implement a large chunk of some programming language in order to be sufficiently flexible. [[User:RB|RB]]
 +
 
 +
=File System Awareness =
 +
==Background: Why be File System Aware?==
 +
Advantages of being FS aware:
 +
* You can pick up sector allocation sizes ([[User:Joachim Metz|Joachim]] do you mean file system block sizes?)
 +
* Some file systems may store things off sector boundaries. (ReiserFS with tail packing)
 +
* Increasingly file systems have compression (NTFS compression)
 +
* Carve just the sectors that are not in allocated files.
 +
 
 +
==Tasks that would be required==
 +
 
 +
==Discussion==
 +
:: As noted above, TSK should be utilized as much as possible, particularly the filesystem-aware portion.  If we want to identify filesystems outside of its supported set, it would be more worth our time to work on implementing them there than in the carver itself.  [[User:RB|RB]]
 +
 
 +
[[User:Joachim Metz|Joachim]] I would like to have the carver (recovery tool) also do recovery using file allocation data or remainders of file allocation data.
 +
 
 +
:::: I guess this tool operates like [[Selective file dumper]] and can recover files in both ways (or not?). Recovering files by using carving can recover files in situations where sleuthkit does nothing (e.g. file on NTFS was deleted using ntfs-3g, or filesystem was destroyed or just unknown). And we should build the list of filesystems supported by carver, not by TSK. [[User:.FUF|.FUF]] 07:08, 29 October 2008 (UTC)
 +
 
 +
:: This tool is still in the early planning stages (requirements discovery), hence few operational details (like precise modes of operation) have been fleshed out - those will and should come later.  The justification for strictly using TSK for the filesystem-sensitive approach is simple: TSK has good filesystem APIs, and it would be foolish to create yet another standalone, incompatible implementation of filesystem(foo) when time would be better spent improving those in TSK, aiding other methods of analysis as well.  This is the same reason individuals that have implemented several other carvers are participating: de-duplication of effort.  [[User:RB|RB]]
 +
 
 +
[[User:Joachim Metz|Joachim]]
 +
I would go as far to ask you all to look beyond the carver as a tool and look from the perspective of the carver as part of the forensic investigation process. In my eyes certain information needed/acquired by the carver could be also very useful investigative information i.e. what part of a hard disk contains empty sectors.
 +
 
 +
[[User:Joachim Metz|Joachim]]
 +
I'm missing a part on the page about the carving challenges (scenarios)
 +
* normal file (file structure, loose text based structure (more a content structure?))
 +
* fragmented file (the file entirely exist)
 +
* a file fragment (the file does not entirely exist)
 +
* intertwined file
 +
* encapsulated file (MPEG/network capture)
 +
* embedded file (JPEG thumbnail)
 +
 
 +
=Validator Construction=
 +
Options:
 +
* Write validators in C/C++
 +
* Have a scripting language for writing them (python? Perl?) our own?
 +
* Use existing programs (libjpeg?) as plug-in validators?
 +
=Existing Code that we have=
 +
=Implementation Timeline=
 +
# gather the available resources/ideas/wishes/needs etc. (I guess we're in this phase)
 +
# start discussing a high level design (in terms of algorithm, facilities, information needed)
 +
## input formats facility
 +
## partition/volume facility
 +
## file system facility
 +
## file format facility
 +
## content facility
 +
## how to deal with fragment detection (do the validators allow for fragment detection?)
 +
## how to deal with recombination of fragments
 +
## do we want multiple carving phases in light of speed/precision tradeoffs
 +
# start detailing parts of the design
 +
## Discuss options for a grammar driven validator?
 +
## Hard-coded plug-ins?
 +
## Which exsisting code can we use?
 +
# start building/assembling parts of the tooling for a prototype
 +
## Implement simple file carving with validation.
 +
## Implement gap carving
 +
# Initial Release
 +
# Implement the ''threaded carving'' that [[User:.FUF|.FUF]] is describing above.

Revision as of 04:12, 31 October 2008

This page is for planning Carver 2.0.

Please, do not delete text (ideas) here. Use something like this:

<s>bad idea</s>
:: good idea

This will look like:

bad idea

good idea

Contents

License

BSD-3.

OS

Linux/FreeBSD/MacOS

(shouldn't this just match what the underlying afflib & sleuthkit cover? RB)
Yes, but you need to test and validate on each. Question: Do we want to support windows? Simsong 21:09, 30 October 2008 (UTC)
Joachim I think we would do wise to design with windows support from the start this will improve the platform independence from the start

Requirements

  • Joachim A name for the tooling I propose coldcut

Joachim Could we do a MoSCoW evaluation of these.

  • AFF and EWF file images supported from scratch. (Joachim I would like to have raw/split raw and device access as well)
  • Joachim volume/partition aware layer (what about carving unpartioned space)
  • File system aware layer.
    • By default, files are not carved. (clarify: only identified? RB; I guess that it operates like Selective file dumper .FUF 07:00, 29 October 2008 (UTC))
  • Plug-in architecture for identification/validation.
    • Joachim support for multiple types of validators
      • dedicated validator
      • validator based on file library (i.e. we could specify/implement a file structure for these)
      • configuration based validator (Can handle config files,like Revit07, to enter different file formats used by the carver.)
  • Ship with validators for:

Joachim I think we should distinguish between file format validators and content validators

    • JPEG
    • PNG
    • GIF
    • MSOLE
    • ZIP
    • TAR (gz/bz2)

Joachim For a production carver we need at least the following formats

    • Grapical Images
      • JPEG (the 3 different types with JFIF/EXIF support)
      • PNG
      • GIF
      • BMP
      • TIFF
    • Office documents
      • OLE2 (Word/Excell content support)
      • PDF
      • Open Office/Office 2007 (ZIP+XML)
    • Archive files
      • ZIP
    • E-mail files
      • PFF (PST/OST)
      • MBOX (text based format, base64 content support)
    • Audio/Video files
      • MPEG
      • MP2/MP3
      • AVI
      • ASF/WMV
      • QuickTime
    • Printer spool files
      • EMF (if I remember correctly)
    • Internet history files
      • index.dat
      • firefox (sqllite 3)
    • Other files
      • thumbs.db
  • Simple fragment recovery carving using gap carving.
    • Joachim have hook in for more advanced fragment recovery?
  • Recovering of individual ZIP sections and JPEG icons that are not sector aligned.
    • Joachim I would propose a generic fragment detection and recovery
  • Autonomous operation (some mode of operation should be completely non-interactive, requiring no human intervention to complete RB)
    • Joachim as much as possible, but allow to be overwritten by user
  • Tested on 500GB-sized images. Should be able to carve a 500GB image in roughly 50% longer than it takes to read the image.
    • Perhaps allocate a percentage budget per-validator (i.e. each validator adds N% to the carving time)
    • Joachim have multiple carving phases for precision/speed trade off?
  • Parallelizable
    • Joachim tunable for different architectures
  • Configuration:
    • Capability to parse some existing carvers' configuration files, either on-the-fly or as a one-way converter.
    • Disengage internal configuration structure from configuration files, create parsers that present the expected structure
    • Joachim The validator should deal with the file structure the carving algorithm should not know anything about the file structure (as in revit07 design)
    • Either extend Scalpel/Foremost syntaxes for extended features or use a tertiary syntax (Joachim I would prefer a derivative of the revit07 configuration syntax which already has encountered some problems of dealing with defining file structure in a configuration file)
  • Can output audit.txt file.
  • Joachim Can output database with offset analysis values i.e. for visualization tooling
  • Joachim Can output debug log for debugging the algorithm/validation
  • Easy integration into ascription software.
    • Joachim I'm no native speaker what do you mean with "ascription software"?

Ideas

  • Use as much TSK if possible. Don't carry your own FS implementation the way photorec does.
    • Joachim using TSK as much as possible would not allow to add your own file system support (i.e. mobile phones, memory structures, cap files)

I would propose wrapping TSK and using it as much as possible but allow to integrate own FS implementations.

  • Extracting/carving data from Thumbs.db? I've used foremost for it with some success. Vinetto has some critical bugs :( .FUF 19:18, 28 October 2008 (UTC)
  • Carving data structures. For example, extract all TCP headers from image by defining TCP header structure and some fields (e.g. source port > 1024, dest port = 80). This will extract all data matching the pattern and write a file with other fields. Another example is carving INFO2 structures and URL activity records from index.dat .FUF 20:51, 28 October 2008 (UTC)
    • This has the opportunity to be extended to the concept of "point at blob FOO and interpret it as BAR"

.FUF added: The main idea is to allow users to define structures, for example (in pascal-like form):

Field1: Byte = 123;
SomeTextLength: DWORD;
SomeText: string[SomeTextLength];
Field4: Char = 'r';
...

This will produce something like this:

Field1 = 123
SomeTextLength = 5
SomeText = 'abcd1'
Field4 = 'r'

(In text or raw forms.)

Opinions?

Opinion: Simple pattern identification like that may not suffice, I think Simson's original intent was not only to identify but to allow for validation routines (plugins, as the original wording was). As such, the format syntax would need to implement a large chunk of some programming language in order to be sufficiently flexible. RB

File System Awareness

Background: Why be File System Aware?

Advantages of being FS aware:

  • You can pick up sector allocation sizes (Joachim do you mean file system block sizes?)
  • Some file systems may store things off sector boundaries. (ReiserFS with tail packing)
  • Increasingly file systems have compression (NTFS compression)
  • Carve just the sectors that are not in allocated files.

Tasks that would be required

Discussion

As noted above, TSK should be utilized as much as possible, particularly the filesystem-aware portion. If we want to identify filesystems outside of its supported set, it would be more worth our time to work on implementing them there than in the carver itself. RB

Joachim I would like to have the carver (recovery tool) also do recovery using file allocation data or remainders of file allocation data.

I guess this tool operates like Selective file dumper and can recover files in both ways (or not?). Recovering files by using carving can recover files in situations where sleuthkit does nothing (e.g. file on NTFS was deleted using ntfs-3g, or filesystem was destroyed or just unknown). And we should build the list of filesystems supported by carver, not by TSK. .FUF 07:08, 29 October 2008 (UTC)
This tool is still in the early planning stages (requirements discovery), hence few operational details (like precise modes of operation) have been fleshed out - those will and should come later. The justification for strictly using TSK for the filesystem-sensitive approach is simple: TSK has good filesystem APIs, and it would be foolish to create yet another standalone, incompatible implementation of filesystem(foo) when time would be better spent improving those in TSK, aiding other methods of analysis as well. This is the same reason individuals that have implemented several other carvers are participating: de-duplication of effort. RB

Joachim I would go as far to ask you all to look beyond the carver as a tool and look from the perspective of the carver as part of the forensic investigation process. In my eyes certain information needed/acquired by the carver could be also very useful investigative information i.e. what part of a hard disk contains empty sectors.

Joachim I'm missing a part on the page about the carving challenges (scenarios)

  • normal file (file structure, loose text based structure (more a content structure?))
  • fragmented file (the file entirely exist)
  • a file fragment (the file does not entirely exist)
  • intertwined file
  • encapsulated file (MPEG/network capture)
  • embedded file (JPEG thumbnail)

Validator Construction

Options:

  • Write validators in C/C++
  • Have a scripting language for writing them (python? Perl?) our own?
  • Use existing programs (libjpeg?) as plug-in validators?

Existing Code that we have

Implementation Timeline

  1. gather the available resources/ideas/wishes/needs etc. (I guess we're in this phase)
  2. start discussing a high level design (in terms of algorithm, facilities, information needed)
    1. input formats facility
    2. partition/volume facility
    3. file system facility
    4. file format facility
    5. content facility
    6. how to deal with fragment detection (do the validators allow for fragment detection?)
    7. how to deal with recombination of fragments
    8. do we want multiple carving phases in light of speed/precision tradeoffs
  3. start detailing parts of the design
    1. Discuss options for a grammar driven validator?
    2. Hard-coded plug-ins?
    3. Which exsisting code can we use?
  4. start building/assembling parts of the tooling for a prototype
    1. Implement simple file carving with validation.
    2. Implement gap carving
  5. Initial Release
  6. Implement the threaded carving that .FUF is describing above.