The following analytic identifies access to SAM, SYSTEM or SECURITY databases' within the file path of
windows\system32\config using Windows Security EventCode 4663. This particular behavior is related to credential access, an attempt to either use a Shadow Copy or recent CVE-2021-36934 to access the SAM database. The Security Account Manager (SAM) is a database file in Windows XP, Windows Vista, Windows 7, 8.1 and 10 that stores users' passwords.
- Type: Hunting
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2021-07-23
- Author: Michael Haag, Mauricio Velazco, Splunk
- ID: 57551656-ebdb-11eb-afdf-acde48001122
Kill Chain Phase
1 2 3 `wineventlog_security` (EventCode=4663) process_name!=*\\dllhost.exe Object_Name IN ("*\\Windows\\System32\\config\\SAM*","*\\Windows\\System32\\config\\SYSTEM*","*\\Windows\\System32\\config\\SECURITY*") | stats values(Accesses) count by process_name Object_Name dest user | `sam_database_file_access_attempt_filter`
The SPL above uses the following Macros:
sam_database_file_access_attempt_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
To successfully implement this search, you must ingest Windows Security Event logs and track event code 4663. For 4663, enable "Audit Object Access" in Group Policy. Then check the two boxes listed for both "Success" and "Failure."
Known False Positives
dllhost.exe will access the files. Every environment will have additional native processes that do as well. Filter by process_name. As an aside, one can remove process_name entirely and add
Associated Analytic Story
|80.0||80||100||The following process $process_name$ accessed the object $Object_Name$ attempting to gain access to credentials on $dest$ by user $user$.|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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