Difference between pages "Bibliography" and "SuperFetch"

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=Disk Disposal and Data Recovery=
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{{Expand}}
* [http://forensic.belkasoft.com/download/info/SSD%20Forensics%202012.pdf Why SSD Drives Destroy Court Evidence, and What Can Be Done About It] by Oleg Afonin and Yuri Gubanov, 2012
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* [http://www.deepspar.com/pdf/DeepSparDiskImagingWhitepaper3.pdf Disk Imaging: A Vital Step in Data Recovery], DeepSpar Data Recovery Systems, November 2006. An in depth look at the many issues that cause data loss / irretrievable data in the data recovery imaging process and how to overcome them.
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* [http://www.actionfront.com/ts_whitepaper.asp Drive-Independent Data Recovery: The Current State-of-the-Art], ActionFront Data Recovery Labs, August 2005.
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* [[Recovering Overwritten Data#The Gutmann Paper|Secure Deletion of Data from Magnetic and Solid-State Memory]], Peter Gutmann, Proceedings of the Sixth Usenix Security Symposium, 1996. [http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html]
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* [http://www-03.ibm.com/financing/pdf/us/recovery/igf4-a032.pdf Hard Drive Disposal: The Overlooked Confidentiality Exposure], FInancial Perspectives, IBM White Paper, November 2003.
+
  
<bibtex>
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SuperFetch is a performance enhancement introduced in [[Microsoft]] [[Windows|Windows Vista]] to reduce the time necessary to launch applications. SuperFetch works with the memory manager service in Windows to analyze memory usage patterns over time to determine the optimal memory content for a given user for a date or time of day. This differs from the [[Prefetch]] technique used in Microsoft Windows XP, which preloads data into memory without analyzing usage patterns.
@Article{garfinkel:remembrance,
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  author =      "Simson Garfinkel and Abhi Shelat",
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  author_a =      "Simson L. Garfinkel and Abhi Shelat",
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  title =        "Remembrance of Data Passed",
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  journal =      "{IEEE} Security and Privacy Magazine",
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  publisher =    "IEEE",
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  year      =        "2002",
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  month    = Jan,
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  url="http://www.simson.net/clips/academic/2003.IEEE.DiskDriveForensics.pdf"
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}
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</bibtex>
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=Evidence Gathering=
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From [http://msdn.microsoft.com/en-us/library/windows/hardware/dn653317(v=vs.85).aspx]: SuperFetch prioritizes the following kinds of pages to remain in memory:
 +
* Pages of applications that are used most frequently overall.
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* Pages of applications that are commonly used when resuming:
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** After extensive hibernation (for example, first thing in the morning).
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** After shorter periods of sleep or hibernation (for example, after lunch).
  
* [http://belkasoft.com/download/info/Live_RAM_Analysis_in_Digital_Forensics.pdf Discovering ephemeral evidence with Live RAM analysis] by Oleg Afonin and Yuri Gubanov, 2013
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If SuperFetch detects that the system drive is a fast SSD (as measured by Windows Experience Index Disk score), then SuperFetch turns off [[ReadyBoot]], [[ReadyBoost]], and the SuperFetch service itself.
* [http://utdallas.edu/~sxs018540/index/docs/byteprints_itcc05.pdf Byteprints: A Tool to Gather Digital Evidence], Sriranjani Sitaraman, Srinivasan Krishnamurthy and S. Venkatesan, Proceedings of the International Conference on Information Technology (ITCC 2005), Las Vegas, Nevada, USA, April 4 - 6, 2005
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=Fake Information=
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== Components ==
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=== Robust performance ===
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Robust performance (or robustness) is a component of SuperFetch to watch for specific file I/O access that might harm system performance by populating the standby lists with unneeded data.
  
* [https://analysis.mitre.org/proceedings/Final_Papers_Files/84_Camera_Ready_Paper.pdf Automatic Detection of Fake File Systems], Neil C. Rowe, International Conference on Intelligence Analysis Methods and Tools, McLean, Virginia, May 2005.
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== Scenarios ==
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SuperFetch distinguishes between different scenarios to accurately measure performance.
  
=Feature Extraction and Data Fusion=
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=== Cold scenario ===
Computer Location Determination Through Geoparsing and Geocoding of
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In a cold scenario, the test applications are not already in memory when the test begins. Cold scenarios measure performance either after a state transition, such as boot or resume from hibernation, or after another application claims most of the available memory, such as after launching and quitting a game.  
Extracted Features
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http://www2.chadsteel.com:8080/Publications/drive_location2.doc
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<bibtex>
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@inproceedings{garfinkel:cda,
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  title="Forensic feature extraction and cross-drive analysis",
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  author="Simson Garfinkel",
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  booktitle={Proceedings of the 6th Annual Digital Forensic Research Workshop (DFRWS)},
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  address = "Lafayette, Indiana",
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  journal="Digital Investigation",
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  year=2006,
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  month=Aug,
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  url="http://www.dfrws.org/2006/proceedings/10-Garfinkel.pdf",
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  location="Lafayette, Indiana"
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}
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</bibtex>
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=Text Mining=
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=== Warm scenario ===
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In a warm scenario, some or all the scenario contents are in memory before measurement. This usually means that the test has run at least once during this logon session.
  
'''Computer Forensic Text Analysis with Open Source Software,''' Christian Johansson, Masters Thesis, Blekinge Tekniska Hogskola, June 2003  http://www.fukt.bth.se/~uncle/papers/master/thesis.pdf
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== Configuration ==
  
=Signed Evidence=
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Because SuperFetch appears to leave a system with no available memory, some users turn it off to create the appearance of having more free memory. The feature can be configured by changing the [[Registry]] value [http://www.codinghorror.com/blog/archives/000688.html]:
<bibtex>
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<pre>
@article{duerr-2004,
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Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters
  title="Information Assurance Applied to Authentication of Digital Evidence",
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Value: EnableSuperfetch
  author="Thomas E. Duerr and Nicholas D. Beser and Gregory P. Staisiunas",
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</pre>
  year=2004,
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  journal="Forensic Science Communications",
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  volume=6,
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  number=4,
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  url="http://www.fbi.gov/hq/lab/fsc/backissu/oct2004/research/2004_10_research01.htm"
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}
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</bibtex>
+
  
 +
A value of zero disables SuperFetch, one enables it for booting only, two for applications, and three for both applications and boot. This setting can also be changed using the Services console, <tt>services.msc</tt> [http://tiredblogger.wordpress.com/2007/03/27/superfetch-not-so-super-for-gaming/].
  
<bibtex>
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== File Formats ==
@article{OppligerR03,
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  author    = {Rolf Oppliger and Ruedi Rytz},
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  title    = {Digital Evidence: Dream and Reality},
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  journal  = {IEEE Security {\&} Privacy},
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  volume    = {1},
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  number    = {5},
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  year      = {2003},
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  pages    = {44-48},
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  url      = {http://doi.ieeecomputersociety.org/10.1109/MSECP.2003.1236234},
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  abstract="Digital evidence is inherently weak. New evidence-gathering technologies-digital black boxes-must be developed and deployed to support investigations of irreproducible events such as digitally signing a document."
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}
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</bibtex>
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=Theory=
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Data for SuperFetch is gathered by the <tt>%SystemRoot%\System32\Sysmain.dll</tt>, part of the Service Host process, <tt>%SystemRoot%\System32\Svchost.exe</tt>, and stored in a series of files in the <tt>%SystemRoot%\Prefetch</tt> directory [http://www.microsoft.com/technet/technetmag/issues/2007/03/VistaKernel/]. These files appear to start with the prefix <tt>Ag</tt> and have a <tt>.db</tt> extension. Note that there are likely more SuperFetch database files named differently, presumably all using the .db extension.
'''A Hypothesis-Based Approach to Digital Forensic Investigations,''' Brian D. Carrier, Ph.D. Dissertation
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Purdue University, May 2006 https://www.cerias.purdue.edu/tools_and_resources/bibtex_archive/archive/2006-06.pdf
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=Other Papers=
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The format of the SuperFetch database files is not fully known, there is available unofficial partial specification [http://blog.rewolf.pl/blog/?p=214] and open source (GPL) dumper for .db files [http://code.google.com/p/rewolf-superfetch-dumper/]. For more information see [[Windows SuperFetch Format|SuperFetch Format]].
  
* [http://papers.ssrn.com/sol3/papers.cfm?abstract_id=531782 A Model for When Disclosure Helps Security: What is Different About Computer and Network Security?], Peter P. Swire, Moritz College of Law of the Ohio State University, Journal on Telecommunications and High Technology Law, Vol. 2, 2004.
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The SuperFetch feature is seeded with some basic usage patterns when the operating system is installed [http://channel9.msdn.com/showpost.aspx?postid=242429].
  
[[Category:Bibliographies]]
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The SuperFetch service is managed by the File Information FS MiniFilter service. It appears that most of the SuperFetch database files are updated (written) when the service is shut down. AgAppLaunch.db is also written when the service starts.
 +
 
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== See Also ==
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* [[Prefetch]]
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* [[ReadyBoost]]
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* [[ReadyBoot]]
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* [[Windows SuperFetch Format|SuperFetch Format]]
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* [[Windows]]
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 +
== External Links ==
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* [http://technet.microsoft.com/en-us/magazine/2007.03.vistakernel.aspx Inside the Windows Vista Kernel: Part 2], by [[Mark Russinovich]], March 2007
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* [http://download.microsoft.com/download/7/E/7/7E7662CF-CBEA-470B-A97E-CE7CE0D98DC2/Win7Perf.docx Performance Testing Guide for Windows], by [[Microsoft]], August 18, 2009 
 +
* [http://en.wikipedia.org/wiki/Windows_Vista_I/O_technologies#SuperFetch Wikipedia: Windows Vista I/O technologies - SuperFetch]
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* [http://channel9.msdn.com/showpost.aspx?postid=242429 Channel 9 Interview with Michael Fortin of Microsoft on SuperFetch]
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* [http://www.informationweek.com/news/showArticle.jhtml?articleID=196902178 Microsoft Predicts The Future With Vista's SuperFetch] from Information Week
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* [http://jessekornblum.com/presentations/dodcc08-2.pdf DC3 Presentation: My You Look SuperFetching], by Jesse Kornblum
 +
 
 +
== Tools ==
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=== Open Source ===
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* [https://code.google.com/p/rewolf-superfetch-dumper/ rewolf-superfetch-dumper]
 +
 
 +
[[Category:Windows]]

Revision as of 06:10, 28 June 2014

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SuperFetch is a performance enhancement introduced in Microsoft Windows Vista to reduce the time necessary to launch applications. SuperFetch works with the memory manager service in Windows to analyze memory usage patterns over time to determine the optimal memory content for a given user for a date or time of day. This differs from the Prefetch technique used in Microsoft Windows XP, which preloads data into memory without analyzing usage patterns.

From [1]: SuperFetch prioritizes the following kinds of pages to remain in memory:

  • Pages of applications that are used most frequently overall.
  • Pages of applications that are commonly used when resuming:
    • After extensive hibernation (for example, first thing in the morning).
    • After shorter periods of sleep or hibernation (for example, after lunch).

If SuperFetch detects that the system drive is a fast SSD (as measured by Windows Experience Index Disk score), then SuperFetch turns off ReadyBoot, ReadyBoost, and the SuperFetch service itself.

Components

Robust performance

Robust performance (or robustness) is a component of SuperFetch to watch for specific file I/O access that might harm system performance by populating the standby lists with unneeded data.

Scenarios

SuperFetch distinguishes between different scenarios to accurately measure performance.

Cold scenario

In a cold scenario, the test applications are not already in memory when the test begins. Cold scenarios measure performance either after a state transition, such as boot or resume from hibernation, or after another application claims most of the available memory, such as after launching and quitting a game.

Warm scenario

In a warm scenario, some or all the scenario contents are in memory before measurement. This usually means that the test has run at least once during this logon session.

Configuration

Because SuperFetch appears to leave a system with no available memory, some users turn it off to create the appearance of having more free memory. The feature can be configured by changing the Registry value [2]:

Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters
Value: EnableSuperfetch

A value of zero disables SuperFetch, one enables it for booting only, two for applications, and three for both applications and boot. This setting can also be changed using the Services console, services.msc [3].

File Formats

Data for SuperFetch is gathered by the %SystemRoot%\System32\Sysmain.dll, part of the Service Host process, %SystemRoot%\System32\Svchost.exe, and stored in a series of files in the %SystemRoot%\Prefetch directory [4]. These files appear to start with the prefix Ag and have a .db extension. Note that there are likely more SuperFetch database files named differently, presumably all using the .db extension.

The format of the SuperFetch database files is not fully known, there is available unofficial partial specification [5] and open source (GPL) dumper for .db files [6]. For more information see SuperFetch Format.

The SuperFetch feature is seeded with some basic usage patterns when the operating system is installed [7].

The SuperFetch service is managed by the File Information FS MiniFilter service. It appears that most of the SuperFetch database files are updated (written) when the service is shut down. AgAppLaunch.db is also written when the service starts.

See Also

External Links

Tools

Open Source