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Description

The following analytic detects the creation of new accounts that have been elevated to local administrators so that you can take immediate action to mitigate the risks and prevent further unauthorized access or malicious activities. This detection is made by using the Splunk query wineventlog_security EventCode=4720 OR (EventCode=4732 Group_Name=Administrators) to search for relevant security events in the Windows event log. When a new account is created or an existing account is added to the Administrators group, this analytic identifies this behavior by looking for EventCode 4720 (A user account was created) or EventCode 4732 (A member was added to a security-enabled global group). This analytic specifically focuses on events where the Group_Name is set to Administrators. This detection is important because it suggests that an attacker has gained elevated privileges and can perform malicious actions with administrative access. This can lead to significant impact, such as unauthorized access to sensitive data, unauthorized modifications to systems or configurations, and potential disruption of critical services. identifying this behavior is crucial for a Security Operations Center (SOC). Next steps include reviewing the details of the security event, including the user account that was created or added to the Administrators group. Also, examine the time span between the first and last occurrence of the event to determine if the behavior is ongoing. Additionally, consider any contextual information, such as the destination where the account was created or added to understand the scope and potential impact of the attack.

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-02-14
  • Author: David Dorsey, Splunk
  • ID: b25f6f62-0712-43c1-b203-083231ffd97d

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1136.001 Local Account Persistence
T1136 Create Account Persistence
Kill Chain Phase
  • Installation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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`wineventlog_security` EventCode=4720 OR (EventCode=4732 Group_Name=Administrators) 
| transaction src_user connected=false maxspan=180m 
| rename src_user as user 
| stats count min(_time) as firstTime max(_time) as lastTime by user dest 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `detect_new_local_admin_account_filter`

Macros

The SPL above uses the following Macros:

:information_source: detect_new_local_admin_account_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • EventCode
  • Group_Name
  • member_id
  • dest
  • user

How To Implement

You must be ingesting Windows event logs using the Splunk Windows TA and collecting event code 4720 and 4732

Known False Positives

The activity may be legitimate. For this reason, it's best to verify the account with an administrator and ask whether there was a valid service request for the account creation. If your local administrator group name is not "Administrators", this search may generate an excessive number of false positives

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
42.0 60 70 A $user$ on $dest$ was added recently. Identify if this was legitimate behavior or not.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 3