Difference between pages "User:Helixgroup" and "Prefetch"

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(some thoughts/comments on the updated outline)
 
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''The danger in using a wiki as a collaboration tool is that other people will edit it.  
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Windows Prefetch files, introduced in [[Windows|Windows XP]], are designed to speed up the application startup process. Prefetch files contain the name of the executable, a Unicode list of DLLs used by that executable, a count of how many times the executable has been run, and a timestamp indicating the last time the program was run. Although Prefetch is present in Windows 2003, by default it is only enabled for boot prefetching. The feature is also found in [[Windows Vista]], where it has been augmented with [[SuperFetch]], [[ReadyBoot]], and [[ReadyBoost]].
  
Information on cryptographic file system was moved to [[File Systems#Cryptographic File Systems]]
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Up to 128 Prefetch files are stored in the <tt>%SystemRoot%\Prefetch</tt> directory [http://blogs.msdn.com/ryanmy/archive/2005/05/25/421882.aspx]. Each file in that directory should contain the name of the application (up to eight (?) characters), a dash, and then an eight character hash of the location from which that application was run, and a <tt>.pf</tt> extension. The filenames should be all uppercase except for the extension. The format of hashes is not known. A sample filename for [[md5deep]] would look like: <tt>MD5DEEP.EXE-4F89AB0C.pf</tt>. If an application is run from two different locations on the drive (i.e. the user runs <tt>C:\md5deep.exe</tt> and then <tt>C:\Apps\Hashing\md5deep.exe</tt>), there will be two different prefetch files in the Prefetch folder.
  
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== Timestamps ==
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Both the [[NTFS]] timestamps for a Prefetch file and the timestamp embedded in each Prefetch file contain valuable information. The creation date of the file indicates the first time the application was executed. Both the modification date of the file and the embedded timestamp indicate the last time the application was executed.
  
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== MetaData ==
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The timestamp embedded within the Prefetch file is a 64-bit (QWORD) [http://msdn2.microsoft.com/en-us/library/ms724284.aspx FILETIME] object located at offset 0x78 from the beginning of the file on [[Windows]] XP.
  
=== Vendor's product overview: ===
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The run count, or number of times the application has been run, is a 4-byte (DWORD) value located at offset 0x90 from the beginning of the file on [[Windows]] XP.
Seagate FDE: http://www.seagate.com/docs/pdf/marketing/PO-Momentus-FDE.pdf
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Network Appliance: http://www.netapp.com/ftp/decru-fileshredding.pdf
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== See Also ==
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* [[SuperFetch]]
  
NetApps DataFort: http://www.decru.com/products/pdf/dsEseries.pdf
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== External Links ==
 
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* [http://milo2012.wordpress.com/2009/10/19/windows-prefetch-folder-tool/ Prefetch-Tool Script] - Python looks Prefetch files up on a web server.
Decru Lifetime Key Management: http://www.decru.com/products/ltkm.htm
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* [http://www.mitec.cz/wfa.html Windows File Analyzer] - Parses Prefetch files, thumbnail databases, shortcuts, index.dat files, and the recycle bin
 
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* [http://www.microsoft.com/whdc/driver/kernel/XP_kernel.mspx#ECLAC Microsoft's description of Prefetch when Windows XP was introduced]
Decru Whitepaper: http://www.forensicswiki.org/images/6/6f/Securing_Storage_White_Paper.pdf
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* [http://msdn.microsoft.com/msdnmag/issues/01/12/XPKernel/default.aspx More detail from Microsoft]
 
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* [http://www.tzworks.net/prototype_page.php?proto_id=1 Windows Prefetch parser] Free tool that can be run on Windows, Linux or Mac OS-X.
Price for Decru DataFort E510 1.6 for NAS: http://infosecuritymag.techtarget.com/ss/0,295796,sid6_iss346_art680,00.html
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DecruDataFort E440: http://www.computerworld.com/hardwaretopics/storage/story/0,10801,78766,00.html
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[[User:Lenageraghty|Lenageraghty]] 22:08, 7 November 2005 (EST)
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=== SAM Useful TCFS site: ===
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Transparent CryptoGraphical file system: http://www.tcfs.it/index.php?pc=2
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TCFS intro: http://www.linuxjournal.com/article/2174
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--[[User:Samlam|Samlam]] 19:56, 13 November 2005 (EST)
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=== ERIC Seagate new offerings: ===
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Full Disk Encryption: http://www.eweek.com/article2/0,1759,1825740,00.asp
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Seagate product specification: http://www.seagate.com/content/docs/pdf/marketing/PO-Momentus-FDE.pdf
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[[User:Samlam|Samlam]] 12:10, 13 November 2005 (EST)
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=== Cryptographcial File Systems: ===
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[[File Systems#Cryptographic File Systems]] Readings on crytographical file systems.
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=== Some Questions / Notes from BJ===
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I added to the existing outline below.  We only get 15 pages max, so we might have to limit ourselves to 2 pages (3 tops) per EFS, so there might be too many items for each EFS listed, but I think it would be good for us to be consistent and have the same items in each EFS.
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I think we should start filling out what we can in the outline during this week, so that we can "refine as we go". 
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Please make sure and add your citations, also.  Do not worry about format; we will do that later; but make sure all the information is there.
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=== Suggestion of outline : ===
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*Introduction (BJ)
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**Definition of an Encrypting File System
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**Purpose/Goal of an EFS
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***Purpose: to add an additional layer of security, controlled by the user, over that user's data
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***Goal: to allow users to feel confident the data placed in the EFS cannot be compromised.
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**Overview of General Workings
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***(description of common functionality and common processes to all or most EFS)
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***You have data in memory, you want to save it to disk, you only want "authorized" people to see it; not even system administrators and/or backup operators
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***You control access by "owning" the key
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***Key is generated (somehow)
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***There is overhead in the process of encrypting/decrypting (unavoidable)
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**Overview of Common Usage
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***Maybe some categories of users and what they are looking for:
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***"business critical applications" like databases, etc. where business relies on data being available and secure
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***"business users" like managers who want to secure employee reviews, HR people wanting to secure salary information, etc.
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***"casual users" people who just want to make sure their data is secure.
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**The currently available systems (market share?)
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**Why we choose CFS TCFS and Network Applicances
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*Study of 4 systems in depth, including why this system is selected for study.
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**CFS (LENA)
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***Overview
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****When Developed
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****Platform(s)
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****Current Version
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***Key Management
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***Ease of Use for End Users
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***Legal Issues
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***Failure Modes
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***Challenges in Installation/Use by System Administrator
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***Performance
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***Cost
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***Conclusion (?? what would that be??)
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**TCFS (SAM)
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***Overview
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****When Developed
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****Platform(s)
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****Current Version
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***Key Management
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***Ease of Use for End Users
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***Legal Issues
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***Failure Modes
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***Challenges in Installation/Use by System Administrator
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***Performance
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***Cost
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***Conclusion (?? what would that be??)
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**Network Appliance DataForte and Seagate (ERIC)
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***Overview
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****When Developed
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****Platform(s)
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****Current Version
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***Key Management
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***Ease of Use for End Users
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***Legal Issues
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***Failure Modes
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***Challenges in Installation/Use by System Administrator
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***Performance
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***Cost
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***Conclusion (?? what would that be??)
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**Windows EFS (BJ)
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***Overview
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****When Developed
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****Platform(s)
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****Current Version
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***Key Management
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***Ease of Use for End Users
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***Legal Issues
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***Failure Modes
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***Challenges in Installation/Use by System Administrator
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***Performance
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***Cost
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***Conclusion (?? what would that be??)
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*Common Issues/Problems (ALL)
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**Impact on computer forensics
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**Impact on end-users (i.e. what if you are away on a business trip and you have to go to the hospital and all of your files are encrypted on your laptop?) (or even worse, what if you die and all your financial information is encrypted?)
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**Impact on business owners (e.g. what if an employee quits and all that person's data files, contact info, etc. are encrypted)
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*Future (ALL)
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**What would be useful to add or remove
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**How we would accomplish the changes we suggest
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*Conclusion. (ALL)
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[[User:Bjl170|Bjl170]] 20:23, 14 November 2005 (EST)
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[[User:Lenageraghty|Lenageraghty]] 08:36, 11 November 2005 (EST)
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===== some thoughts/comments on the updated outline =====
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* We are examining 3 cyptographical file system - why do we choose the 3 we choose ?
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** Freeware is popular CFS, TCFS is free.
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** CFS is quite often referenced.  It is one of the early most widely used system.
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** Net Applicance is a commercial system. Possibly an end-to-end solution (?)
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** Scope of this project: multi-user file systems, as oppose to a single disk drive system.
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** What are some of the existing system ?
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* Betty, it was previously agreed that there are 3 EFS.  Sam prefers 3 EFS to 4.
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** Is there any reason why you choose Windows ?  I will write up why we choose the 3 that I know of.  I am not sure why Windows.  I probably write up a snippet for the 3, and you can add the reason for choosing Windows.
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[[User:Lenageraghty|Lenageraghty]] 23:32, 14 November 2005 (EST)
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=== Questions : ===
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* What systems are currently available ?
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[[User:Lenageraghty|Lenageraghty]] 08:48, 11 November 2005 (EST)
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=== Suggestions/Questions/Outline ?: ===
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* Solutions from other storage vendors.
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* Desirable features for a cryptographical file system.
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* cost
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** performance
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** total solution for end-users
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** Key management for cryptographical file system
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** Ease of use by end-users
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** Failure modes
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** Challenges in using/installing
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[[User:Lenageraghty|Lenageraghty]] 22:48, 7 November 2005 (EST)
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===== comment from TA (Joe)  =====
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That looks like some of the right inroads.  Remember that the paper is
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not very long, so you may want to focus on the three systems and do a
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deep analysis.  Certainly some things to think about:
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      Simson's lecture where he talked about it
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      Failure modes of such systems
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      Challenges in using/installing
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''comment from teacher:'' Please remember that this Wiki is publically accessible on the Internet. It's great if you can improve the resource for everbody. But do try to do that, rather than just creating your own space...
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===== Uploading pieces of our writeup =====
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[[Image:HelixCFS.doc]] Lena's writeup on CFS
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Devaition from outline: 
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* Did not mention current release, which is not really relevant. (It is 1.4.1 if anyone is interested)
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* Describe the security provided by CFS.
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* No legal issue.
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* Not sure what is meant by failure mode: I assume lost of key ?
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  In any case, we can use backup/restore. Failure is generally taken
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  care of by the system administrator, so failure mode is
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  part of "ease of user" for the system administrator.
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[[User:Lenageraghty|Lenageraghty]] 23:35, 14 November 2005 (EST)
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Revision as of 10:53, 7 February 2011

Information icon.png

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

Windows Prefetch files, introduced in Windows XP, are designed to speed up the application startup process. Prefetch files contain the name of the executable, a Unicode list of DLLs used by that executable, a count of how many times the executable has been run, and a timestamp indicating the last time the program was run. Although Prefetch is present in Windows 2003, by default it is only enabled for boot prefetching. The feature is also found in Windows Vista, where it has been augmented with SuperFetch, ReadyBoot, and ReadyBoost.

Up to 128 Prefetch files are stored in the %SystemRoot%\Prefetch directory [1]. Each file in that directory should contain the name of the application (up to eight (?) characters), a dash, and then an eight character hash of the location from which that application was run, and a .pf extension. The filenames should be all uppercase except for the extension. The format of hashes is not known. A sample filename for md5deep would look like: MD5DEEP.EXE-4F89AB0C.pf. If an application is run from two different locations on the drive (i.e. the user runs C:\md5deep.exe and then C:\Apps\Hashing\md5deep.exe), there will be two different prefetch files in the Prefetch folder.

Contents

Timestamps

Both the NTFS timestamps for a Prefetch file and the timestamp embedded in each Prefetch file contain valuable information. The creation date of the file indicates the first time the application was executed. Both the modification date of the file and the embedded timestamp indicate the last time the application was executed.

MetaData

The timestamp embedded within the Prefetch file is a 64-bit (QWORD) FILETIME object located at offset 0x78 from the beginning of the file on Windows XP.

The run count, or number of times the application has been run, is a 4-byte (DWORD) value located at offset 0x90 from the beginning of the file on Windows XP.

See Also

External Links