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Description

This analytic is to detect a suspicious registry modification to disable change password feature of the windows host. This registry modification may disables the Change Password button on the Windows Security dialog box (which appears when you press Ctrl+Alt+Del). As a result, users cannot change their Windows password on demand. This technique was seen in some malware family like ransomware to prevent the user to change the password after ownning the network or a system during attack. This windows feature may implemented by administrator to prevent normal user to change the password of a critical host or server, In this type of scenario filter is needed to minimized false positive.

  • Type: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Change, Endpoint
  • Last Updated: 2023-04-27
  • Author: Steven Dick, Teoderick Contreras, Splunk
  • ID: 0df33e1a-9ef6-11ec-a1ad-acde48001122

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1112 Modify Registry Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path= "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableChangePassword" Registry.registry_value_data = "0x00000001") BY _time span=1h Registry.dest Registry.registry_path Registry.registry_key_name Registry.registry_value_name Registry.registry_value_data Registry.process_guid 
| `drop_dm_object_name(Registry)` 
| where isnotnull(registry_value_data) 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_disable_change_password_through_registry_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_disable_change_password_through_registry_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
  • Registry.dest
  • Registry.registry_value_name
  • Registry.registry_key_name
  • Registry.registry_path
  • Registry.registry_value_data
  • Registry.process_guid

How To Implement

To successfully implement this search, you need to be ingesting logs with the registry value name, registry path, and registry value data from your endpoints. If you are using Sysmon, you must have at least version 2.0 of the offical Sysmon TA. https://splunkbase.splunk.com/app/5709

Known False Positives

This windows feature may implemented by administrator to prevent normal user to change the password of a critical host or server, In this type of scenario filter is needed to minimized false positive.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
49.0 70 70 Registry modification in "DisableChangePassword" on $dest$

: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