Windows Admin Password Changed by Non-Admin

name: Windows Admin Password Changed by Non-Admin
id: 6d4c4d88-cd60-43a1-8c70-c74a9614f724
version: 1
creation_date: '2026-04-27'
modification_date: '2026-04-27'
author: Raven Tait, Splunk
status: production
type: TTP
description: |-
    The following analytic detects when a unprivileged user changes an Admin accounts password. This is a common artifact of successful exploitation of the BlueHammer Windows Defender privilege escalation. The attacker's process momentarily changes the passwords of high-value local accounts including the built-in Administrator to spawn an authenticated shell session, then immediately reverts the passwords to avoid detection. This uses EventID 4723 to log this activity.
data_source:
    - Windows Event Log Security 4723
search: |-
    `wineventlog_security`
    EventCode=4723
    | rex field=object_id "-(?<target_rid>\d+)$"
    | rex field=SubjectUserSid "-(?<subject_rid>\d+)$"
    | where target_rid="500" OR tonumber(target_rid) IN (512,513,518,519,520)
    | where tonumber(subject_rid) >= 1000
    | where SubjectUserSid != object_id
    | stats count min(_time) as firstTime
                  max(_time) as lastTime
      by dest user object_id EventCode src_user
         SubjectUserSid SubjectLogonId PrivilegeList
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_admin_password_changed_by_non_admin_filter`
how_to_implement: |-
    The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives: |-
    Some IT support tools or automated scripts may change administrator passwords during maintenance. Verify changes against authorized administrative activities to reduce false alerts.
references:
    - https://github.com/Nightmare-Eclipse/BlueHammer
finding:
    title: Non-Administrator account $src_user$ changed password of Admin account $user$ on $dest$.
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Windows Privilege Escalation
    - BlueHammer
asset_type: Endpoint
mitre_attack_id:
    - T1068
    - T1543.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
cve:
    - CVE-2026-33825