Application Compatibility Cache (Shim Cache)

The Shim Cache tracks executables that require compatibility settings to run properly. It's stored in memory and only written to the cache during system shutdown.

Overview:

• Purpose: Used by Windows to ensure compatibility with older applications by maintaining metadata about executable files.

• Registry Location:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\AppCompatCache

• Data Stored:

  • File paths, timestamps, and information about recently executed binaries.

Benefits for DFIR:

• Evidence of Execution: Identifies executables that have been run, even if they were later deleted.

• Historical Records: Preserves data for files no longer present on the disk.

How It Works:

• Logs metadata when an executable is run, storing:

  • File Path: Full path to the executable.

  • Timestamp: Last modified time.

  • Metadata: Indicators of compatibility settings.

  • File Name: Provides the name of the executable.

  • Full Path: Indicates the complete path to the executable file.

  • Standard Info Last Modified Date: Shows the last modified date of the executable.

  • Size of the Binary: Records the size of the executable file.

  • Execution Status: Indicates whether the file ran on the system.

  Note: Even if the file metadata changes, it will still be recorded in the shim cache.

Tools:

• ShimCacheParser: Decodes and interprets data.

• FTK Imager: Extracts registry hives for offline analysis.

• SANS AppCompatCache Parser: Comprehensive parser for cached entries

for example :

there is plugin in volatility3 we can used to analyses image for Shim Cache , for example :