The following analytic identifies a new local user account added to a computer. Note that, this should be restricted to critical assets.
- Type: Anomaly
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2022-10-05
- Author: Michael Haag, Splunk
- ID: 3fb2e8e3-7bc0-4567-9722-c5ab9f8595eb
Kill Chain Phase
- Actions on Objectives
- CIS 3
- CIS 5
- CIS 16
1 2 3 4 5 6 | tstats `security_content_summariesonly` values(All_Changes.result_id) as result_id count min(_time) as firstTime max(_time) as lastTime from datamodel=Change where All_Changes.result_id=4720 by All_Changes.user All_Changes.dest All_Changes.result All_Changes.action | `drop_dm_object_name("All_Changes")` | `security_content_ctime(lastTime)` | `security_content_ctime(firstTime)` | `windows_create_local_account_filter`
The SPL above uses the following Macros:
windows_create_local_account_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
This search requires you to have enabled your Group Management Audit Logs in your Local Windows Security Policy and be ingesting those logs. More information on how to enable them can be found here: http://whatevernetworks.com/auditing-group-membership-changes-in-active-directory/
Known False Positives
It is possible that an administrator created the account. Verifying activity with an administrator is advised. This analytic is set to anomaly to allow for risk to be added. Filter and tune as needed. Restrict to critical infrastructure to reduce any volume.
Associated Analytic Story
|18.0||20||90||The following $user$ was added to $dest$ as a local account.|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
source | version: 1