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Description

This Splunk detection identifies situations where over five unique Windows account passwords are changed within a 10-minute interval, captured by Event Code 4724 in the Windows Security Event Log. The query utilizes the wineventlog_security dataset, organizing data into 10-minute periods to monitor the count and distinct count of TargetUserName, the accounts with altered passwords. Rapid password changes across multiple accounts are atypical and might indicate unauthorized access or an internal actor compromising account security. Teams should calibrate the detection's threshold and timeframe to fit their specific operational context.

  • Type: TTP

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

  • Last Updated: 2024-02-20
  • Author: Mauricio Velazco, Splunk
  • ID: faefb681-14be-4f0d-9cac-0bc0160c7280

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=4724 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_account_passwords_changed_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_multiple_account_passwords_changed_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
24.0 40 60 User $src_user$ changed the passwords of 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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