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Description

The following analytic flags when more than five unique Windows accounts are deleted within a 10-minute period, identified by Event Code 4726 in the Windows Security Event Log. Using the wineventlog_security dataset, it segments data into 10-minute intervals to monitor account deletions, a pattern that could suggest malicious intent like an attacker erasing traces. Teams should adjust the detection's threshold and timeframe to suit their specific environment.

  • Type: TTP

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

  • Last Updated: 2024-02-21
  • Author: Mauricio Velazco, Splunk
  • ID: 49c0d4d6-c55d-4d3a-b3d5-7709fafed70d

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1098 Account Manipulation Persistence, Privilege Escalation
T1078 Valid Accounts Defense Evasion, Persistence, Privilege Escalation, Initial Access
Kill Chain Phase
  • Installation
  • Exploitation
  • Delivery
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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 `wineventlog_security` EventCode=4726 status=success 
| bucket span=10m _time 
| stats count dc(user) as unique_users values(user) as user by EventCode signature _time src_user SubjectDomainName TargetDomainName Logon_ID 
| where unique_users > 5 
| `windows_multiple_accounts_deleted_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_multiple_accounts_deleted_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
  • success
  • TargetUserName
  • SubjectUserName
  • src_user
  • SubjectDomainName
  • TargetDomainName
  • Logon_ID
  • user

How To Implement

To successfully implement this search, you need to be ingesting Domain Controller events with the Windows TA. The Advanced Security Audit policy setting Audit User Account Management within Account Management needs to be enabled.

Known False Positives

Service accounts may be responsible for the creation, deletion or modification of accounts for legitimate purposes. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
18.0 30 60 User $src_user$ deleted multiple accounts in a short period of time.

: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

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