SRUM

Windows DFIR notes are no longer maintained on InfoSec-Notes. Updated versions can be found on: artefacts.help.

Overview

Introduced in Windows 8.

Location:

• SRUM database: %SystemRoot%\System32\SRU\SRUDB.dat.

• (Optional) SOFTWARE (%SystemRoot%\System32\config\SOFTWARE) registry hive to translate some information in the database (user SID to username and network interfaces information notably).

Yield information related to the system usage, including programs execution and executed programs' network usage. Historical data only for the last 30 to 60 days is stored in the SRUM database.

Entries are not associated with their timestamp of occurrence but with the timestamp of insertion in the SRUM database. As entries are only written to the SRUM database every hour, timestamps are thus precise to the hour (with multiple entries usually sharing the same insertion timestamp).

The System Resource Usage Monitor (SRUM) is a feature that records numerous metrics of system activities. Among the various information stored, the following two tables hold the most commonly valuable data for forensics investigations:

• Application Resource Usage table (GUID {D10CA2FE-6FCF-4F6D-848E-B2E99266FA89}), that tracks programs execution. For each entry in the Application Resource Usage table (SrumECmd's AppResourceUseInfo output), the following information may be recorded:

  • Timestamp of the SRUM entry creation.

  • Full path of the executable or application information / description for built-in components.

  • User SID of the user executing the process.

  • Metrics on CPU usage (CPU time in foreground and background).

  • Metrics on I/O operations (foreground / background number of read / write operations and bytes read / written).

• App Timeline Provider table (GUID {5C8CF1C7-7257-4F13-B223-970EF5939312}), that also tracks programs execution. For each entry in the Application Resource Usage table (SrumECmd's AppTimelineProvider output), the following information may be recorded:

  • Timestamp of the SRUM entry creation.

  • Name of the executable and description for built-in components.

  • Timestamp of compilation of the executable.

  • User SID of the user executing the process.

  • Timestamp of seemingly approximate end of execution.

  • Total duration of execution (in milliseconds).

• Network Data Usage table (GUID {973F5D5C-1D90-4944-BE8E-24B94231A174}), that tracks programs execution and network usage of the executed programs. For each entry in the Network Data Usage table (SrumECmd's NetworkUsages output), the following information may be recorded:

  • Timestamp of the SRUM entry creation.

  • Full path of the executable or application information / description for built-in components.

  • Metrics on network data usage (bytes sent and receive on a given network interface).

Some of the information recorded in the SRUM database be viewed using the Windows Task Manager ("App history" tab).

More information on the tables in the SRUM database is referenced in the srum-dump project's mapping file.

Parsing

Repairing the SRUDB.dat database

As the copied SRUM database will likely not be in a "clean state", the database will have to be repaired. This can be accomplished using the esentutl utility. It is recommended to make a copy of the SRU directory before repairing the database.

# The following commands should be executed in the directory containing the UAL database files.

esentutl.exe /r sru /i

esentutl.exe /p SRUDB.dat

SrumECmd

The SrumECmd utility (KAPE's SrumECmd module) can parse and extract information from the SRUDB.dat database, and correlates information from the SOFTWARE registry hive.

# Parses the specified SRUM database, using the optionally provided SOFTWARE registry hive.
SrumECmd.exe -f <SRUDB.dat | SRUM_DB_FILE> [-r <SOFTWARE>] --csv <OUTPUT_DIRECTORY>

# Recursively look for SRUDB.dat and SOFTWARE files in the specified directory.
SrumECmd.exe -d <DIRECTORY> --csv <OUTPUT_DIRECTORY>

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References

https://isc.sans.edu/forums/diary/System+Resource+Utilization+Monitor/21927/

https://www.youtube.com/watch?v=Uw8n4_o-ETM