Difference between pages "Solid State Drive (SSD) Forensics" and "Apple Safari"

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(Bibliography: added recent article on SSD forensics.)
 
 
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Solid State Drives pose a variety of interesting challenges for computer forensics in comparison with traditional rotating magnetic platter hard drives.  
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{{Expand}}
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Apple Safari is the default [[Web Browser|web browser]] included with [[Mac OS X]].
  
Most SSD devices are based on flash memory; some have battery backed SRAM or DRAM with a flash backing store.
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== Locations ==
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The Safari browser uses different locations to store different kind of information.
  
Flash has a number of key properties that complicate its use in computer storage systems and subsequent forensic analysis:
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The user directory:
# Internally, flash memory is not divided into the traditional 512 byte blocks, but instead is in pages of 2KiB, 4KiB, or larger, although it is still presented to the host computer in blocks
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# Whilst hard drives can be written in a single pass, flash memory pages must be erased (in whole) before they can be rewritten.
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# Rewriting a block at the operating system level does not necessarily rewrite the same page in the flash memory due to the controller remapping data to spread wear or avoid failing pages
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# Each page can be erased and rewritten a limited number of times – typically 1000 to 10,000. (Hard drive sectors, in contrast, can be rewritten millions of times or more.)
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# Flash data is often encrypted on the drive, and can be "erased" by telling the controller to forget the old key and generate a new one, as well as marking all blocks as unused
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The controller in a flash SSD is significantly more complex in the number of tasks it has to perform in comparison to a magnetic rotating drive, with the following features:
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On MacOS-X
# ''wear leveling'' – that is, spreading the writes to flash out among different sectors. Wear leveling is typically done with a ''flash translation layer'' that maps ''logical sectors'' (or LBAs) to ''physical pages''.  Most FTLs are contained within the SSD device and are not accessible to end users.
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<pre>
# ''read/modify/relocate+write'' - if the controller allows rewriting of a partial flash page, it must read the entire page, modify the sector that is being written, and write the new flash page in a new/fresh location which has been previously erased. the old pre-modification data's page is then queued for erase.
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/Users/$USER/Library/Safari/
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</pre>
  
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On Windows XP
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<pre>
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C:\Documents and Settings\%USERNAME%\Application Data\Apple Computer\Safari\
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</pre>
  
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On Windows 7
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<pre>
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C:\Users\{user}\AppData\Roaming\Apple Computer\Safari\
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</pre>
  
==Bibliography==
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The cache directory:
<bibtex>
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@inproceedings{wei2011,
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  author = {Yuri Gubanov, Oleg Afonin},
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  title = {Why SSD Drives Destroy Court Evidence, and What Can Be Done About It},
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  booktitle={Article},
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  year = 2012,
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  keywords = {ssd forensics},
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  added-at = {2012-09-01T09:00:00.000+0100},
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  url={http://forensic.belkasoft.com/en/why-ssd-destroy-court-evidence}
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}
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</bibtex>
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<bibtex>
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On MacOS-X
@inproceedings{wei2011,
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<pre>
  author = {Michael Wei and Laura M. Grupp and Frederick M. Spada and Steven Swanson},
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/Users/$USER/Library/Caches/com.apple.Safari/
  title = {Reliably Erasing Data from Flash-Based Solid State Drives},
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</pre>
  booktitle={FAST 2011},
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  year = 2011,
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  keywords = {erasing flash security ssd},
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  added-at = {2011-02-22T09:22:03.000+0100},
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  url={http://cseweb.ucsd.edu/users/m3wei/assets/pdf/FMS-2010-Secure-Erase.pdf},
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  biburl = {http://www.bibsonomy.org/bibtex/27c408ad559fc19f829717f485707a909/schmidt2}
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}
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</bibtex>
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<bibtex>
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@article{bell2011,
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author="Graeme B. Bell and Richard Boddington",
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title="Solid State Drives: The Beginning of the End for Current Practice in Digital Forensic Recovery?",
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journal="Journal of Digital Forensics, Security and Law",
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volume=5,
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issue=3,
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year=2011,
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url={http://www.jdfsl.org/subscriptions/JDFSL-V5N3-Bell.pdf}
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}
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</bibtex>
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<bibtex>
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@inproceedings{Billard:2010:MSU:1774088.1774426,
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author = {Billard, David and Hauri, Rolf},
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title = {Making sense of unstructured flash-memory dumps},
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booktitle = {Proceedings of the 2010 ACM Symposium on Applied Computing},
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series = {SAC '10},
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year = {2010},
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isbn = {978-1-60558-639-7},
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location = {Sierre, Switzerland},
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pages = {1579--1583},
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numpages = {5},
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url = {http://doi.acm.org/10.1145/1774088.1774426},
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doi = {http://doi.acm.org/10.1145/1774088.1774426},
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acmid = {1774426},
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publisher = {ACM},
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address = {New York, NY, USA},
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keywords = {cell phone, computer forensics, file carving, flash-memory dumps, forensics},
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}
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</bibtex>
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<bibtex>
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@mastersthesis{regan:2009,
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  title="The Forensic Potential of Flash Memory",
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  author="James E. Regan",
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  school="Naval Postgraduate School",
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  address="Monterey, CA",
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  date=Sep,
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  year=2009,
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  pages=86,
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  url="http://handle.dtic.mil/100.2/ADA509258"
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}
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</bibtex>
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<bibtex>
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@inproceedings{Phillips:2008:RDU:1363217.1363243,
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author = {Phillips, B. J. and Schmidt, C. D. and Kelly, D. R.},
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title = {Recovering data from USB flash memory sticks that have been damaged or electronically erased},
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booktitle = {Proceedings of the 1st international conference on Forensic applications and techniques in telecommunications, information, and multimedia and workshop},
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series = {e-Forensics '08},
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year = {2008},
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isbn = {978-963-9799-19-6},
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location = {Adelaide, Australia},
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pages = {19:1--19:6},
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articleno = {19},
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numpages = {6},
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url = {http://portal.acm.org/citation.cfm?id=1363217.1363243},
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acmid = {1363243},
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publisher = {ICST (Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering)},
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address = {ICST, Brussels, Belgium, Belgium},
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keywords = {data recovery, flash memory, semiconductor data remanence},
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}
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</bibtex>
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==Presentations==
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On Windows XP
* [http://asalor.blogspot.com/2011/08/trim-dm-crypt-problems.html Milan Broz's blog - TRIM & dm-crypt ... problems?]
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<pre>
* [http://www.snia.org/events/storage-developer2009/presentations/thursday/NealChristiansen_ATA_TrimDeleteNotification_Windows7.pdf ATA Trim / Delete Notification Support in Windows 7], Neal Christiansen, Storage Developer 2009
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C:\Documents and Settings\%USERNAME%\Local Settings\Application Data\Apple Computer\Safari\
* [http://www.slideshare.net/digitalassembly/challenges-of-ssd-forensic-analysis Challenges of SSD Forensic Analysis], Digital Assembly,
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</pre>
* [http://www.youtube.com/watch?v=WcO7xn0wJ2I Solid State Drives: Ruining Forensics], by Scott Moulton, DEFCON 16 (2008)
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* Scott Moulton, Shmoocon 20008,  SSD drives vs. Hard Drives.
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On Windows 7
** [http://www.youtube.com/watch?v=l4hbdZFWGog SSD Flash Hard Drives - Shmoocon 2008 - Part 1]
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<pre>
** [http://www.youtube.com/watch?v=mglEnIPnzjo SSD Flash Hard Drives - Shmoocon 2008 - Part 2]
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C:\Users\{user}\AppData\Local\Apple Computer\Safari\
** [http://www.youtube.com/watch?v=3psy_d-pyNg SSD Flash Hard Drives - Shmoocon 2008 - Part 3]
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</pre>
** [http://www.youtube.com/watch?v=pKeZvhDd5c4 SSD Flash Hard Drives - Shmoocon 2008 - Part 4]
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** [http://www.youtube.com/watch?v=9XMBdDypSO4 SSD Flash Hard Drives - Shmoocon 2008 - Part 5]
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== History ==
** [http://www.youtube.com/watch?v=LY36SWbfQg0 SSD Flash Hard Drives - Shmoocon 2008 - Part 6]
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The browser history is stored in a [[Property list | binary plist file]] named '''History.plist''' in the user directory.
* [http://risky.biz/RB185 Risky Business #185], Peter Gutmann talks SSD forensics, March 4, 2011 (Radio Show)
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This file can be viewed directly in [[Mac OS X]] by opening file in the [[Property List Editor]] program.
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For each web site, the program records the URL visited, the date and time of the last visit, and the number of times the site has been visited.
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The date and time values are stored as a floating point value containing the number of seconds since Jan 1, 2001 00:00:00 UTC.
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On a Windows PC History.plist file can be opened in [[Oxygen Forensic Plist Viewer]] software.
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The downloads history can also be found in the user directory in a binary plist file named '''Downloads.plist'''.
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== Cache ==
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The Safari cache is stored in '''Cache.db''' in the cache directory.
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This file uses the [[SQLite database format]].
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== External Links ==
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* [http://www.apple.com/macosx/features/safari/ Official website]
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* [http://www.appleexaminer.com/files/Safari_Cache.db_Revisited.pdf Safari Cache Revisited] by Sean Cavanaugh
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== Tools ==
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* [http://jafat.sourceforge.net/ J.A.F.A.T. Archive of Forensics Analysis Tools] home of Safari Forensic Tools (SFT)
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[[Category:Applications]]
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[[Category:Web Browsers]]

Revision as of 06:03, 22 September 2013

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Please help to improve this article by expanding it.
Further information might be found on the discussion page.

Apple Safari is the default web browser included with Mac OS X.

Locations

The Safari browser uses different locations to store different kind of information.

The user directory:

On MacOS-X

/Users/$USER/Library/Safari/

On Windows XP

C:\Documents and Settings\%USERNAME%\Application Data\Apple Computer\Safari\

On Windows 7

C:\Users\{user}\AppData\Roaming\Apple Computer\Safari\

The cache directory:

On MacOS-X

/Users/$USER/Library/Caches/com.apple.Safari/

On Windows XP

C:\Documents and Settings\%USERNAME%\Local Settings\Application Data\Apple Computer\Safari\

On Windows 7

C:\Users\{user}\AppData\Local\Apple Computer\Safari\

History

The browser history is stored in a binary plist file named History.plist in the user directory.

This file can be viewed directly in Mac OS X by opening file in the Property List Editor program.

For each web site, the program records the URL visited, the date and time of the last visit, and the number of times the site has been visited.

The date and time values are stored as a floating point value containing the number of seconds since Jan 1, 2001 00:00:00 UTC.

On a Windows PC History.plist file can be opened in Oxygen Forensic Plist Viewer software.

The downloads history can also be found in the user directory in a binary plist file named Downloads.plist.

Cache

The Safari cache is stored in Cache.db in the cache directory.

This file uses the SQLite database format.

External Links

Tools