Difference between pages "Prefetch" and "Windows Application Compatibility"

From ForensicsWiki
(Difference between pages)
Jump to: navigation, search
(See Also)
 
(sysmain.sdb)
 
Line 1: Line 1:
{{Expand}}
+
{{expand}}
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]].
+
  
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.
+
== sysmain.sdb ==
 +
System compatibility database.
  
== Timestamps ==
+
== RecentFileCache.bcf ==
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.
+
In Windows 7 the RecentFileCache.bcf file is stored in:
 +
<pre>
 +
C:\Windows\AppCompat\Programs\
 +
</pre>
  
== MetaData ==
+
== Amcache.hve ==
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.
+
The Amcache.hve file is a [[Windows NT Registry File (REGF)]].
  
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.
+
In Windows 8 the Amcache.hve file is stored in:
 +
<pre>
 +
C:\Windows\AppCompat\Programs\
 +
</pre>
  
== See Also ==
+
== AppCompatCache ==
* [[SuperFetch]]
+
In Windows 2000 and XP:
* [[Prefetch_XML]]
+
<pre>
 +
Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\AppCompatibility
 +
</pre>
 +
 
 +
In Windows 2003 and later:
 +
<pre>
 +
Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\AppCompatCache
 +
</pre>
  
 
== External Links ==
 
== External Links ==
* [http://milo2012.wordpress.com/2009/10/19/windows-prefetch-folder-tool/ Prefetch-Tool Script] - Python looks Prefetch files up on a web server.
+
* [http://technet.microsoft.com/en-us/library/dd837644(v=ws.10).aspx Technet: Understanding Shims], by [[Microsoft]]
* [http://www.mitec.cz/wfa.html Windows File Analyzer] - Parses Prefetch files, thumbnail databases, shortcuts, index.dat files, and the recycle bin
+
* [http://msdn.microsoft.com/en-us/library/bb432182(v=vs.85).aspx MSDN: Application Compatibility Database], by [[Microsoft]]
* [http://www.microsoft.com/whdc/driver/kernel/XP_kernel.mspx#ECLAC Microsoft's description of Prefetch when Windows XP was introduced]
+
* [http://www.alex-ionescu.com/?p=39 Secrets of the Application Compatilibity Database (SDB) – Part 1], by [[Alex Ionescu]], May 20, 2007
* [http://msdn.microsoft.com/msdnmag/issues/01/12/XPKernel/default.aspx More detail from Microsoft]
+
* [http://www.alex-ionescu.com/?p=40 Secrets of the Application Compatilibity Database (SDB) – Part 2], by [[Alex Ionescu]], May 21, 2007
* [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.
+
* [http://www.alex-ionescu.com/?p=41 Secrets of the Application Compatilibity Database (SDB) – Part 3], by [[Alex Ionescu]], May 26, 2007
 +
* [http://recxltd.blogspot.com/2012/04/windows-appcompat-research-notes-part-1.html Windows AppCompat Research Notes - Part 1], by Ollie, 28 April 2012
 +
* [http://recxltd.blogspot.com/2012/05/windows-appcompat-research-notes-part-2.html Windows AppCompat Research Notes - Part 2], by Ollie, 4 May 2012
 +
* [https://dl.mandiant.com/EE/library/Whitepaper_ShimCacheParser.pdf Leveraging the Application Compatibility Cache in Forensic Investigations], by [[Andrew Davis]], May 4, 2012
 +
* [http://journeyintoir.blogspot.ch/2013/12/revealing-recentfilecachebcf-file.html Revealing the RecentFileCache.bcf File], by [[Corey Harrell]], December 2, 2013
 +
* [http://journeyintoir.blogspot.ch/2013/12/revealing-program-compatibility.html Revealing Program Compatibility Assistant HKCU AppCompatFlags Registry Keys], by [[Corey Harrell]], December 17, 2013
 +
* [http://journeyintoir.blogspot.ch/2014/04/triaging-with-recentfilecachebcf-file.html Triaging with the RecentFileCache.bcf File], by [[Corey Harrell]], April 21, 2014

Latest revision as of 00:06, 9 July 2014

Information icon.png

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

sysmain.sdb

System compatibility database.

RecentFileCache.bcf

In Windows 7 the RecentFileCache.bcf file is stored in:

C:\Windows\AppCompat\Programs\

Amcache.hve

The Amcache.hve file is a Windows NT Registry File (REGF).

In Windows 8 the Amcache.hve file is stored in:

C:\Windows\AppCompat\Programs\

AppCompatCache

In Windows 2000 and XP:

Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\AppCompatibility

In Windows 2003 and later:

Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\AppCompatCache

External Links