ESXi Lockdown Mode Disabled

SPLUNK detection rule by Raven Tait, Splunk · Apache-2.0

This detection identifies when Lockdown Mode is disabled on an ESXi host, which can indicate that a threat actor is attempting to weaken host security controls. Disabling Lockdown Mode allows broader remote access via SSH or the host client and may precede further malicious actions such as data exfiltration, lateral movement, or VM tampering.

name: ESXi Lockdown Mode Disabled
id: 07c0d28a-9a9b-409f-8d4b-65355bd19ead
version: 5
creation_date: '2025-07-11'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: TTP
description: This detection identifies when Lockdown Mode is disabled on an ESXi host, which can indicate that a threat actor is attempting to weaken host security controls. Disabling Lockdown Mode allows broader remote access via SSH or the host client and may precede further malicious actions such as data exfiltration, lateral movement, or VM tampering.
data_source:
    - VMWare ESXi Syslog
search: '`esxi_syslog` Message IN ("*lockdownmode.disabled*", "*Administrator access to the host has been enabled*") | rex field=_raw "Z (?<dest>[\w\.]+)\s" | stats min(_time) as firstTime max(_time) as lastTime count by dest Message | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `esxi_lockdown_mode_disabled_filter`'
how_to_implement: This is based on syslog data generated by VMware ESXi hosts. To implement this search, you must configure your ESXi systems to forward syslog output to your Splunk deployment. These logs must be ingested with the appropriate Splunk Technology Add-on for VMware ESXi Logs, which provides field extractions and CIM compatibility.
known_false_positives: Limited false positives in most environments, however tune as needed.
drilldown_searches:
    - name: View the detection results for - "$dest$"
      search: '%original_detection_search% | search  dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: Lockdown Mode has been disabled on ESXi host $dest$.
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - ESXi Post Compromise
    - Black Basta Ransomware
asset_type: Infrastructure
mitre_attack_id:
    - T1685
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: application
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562/esxi_lockdown_disabled/esxi_lockdown_disabled.log
          source: vmware:esxlog
          sourcetype: vmw-syslog
      test_type: unit

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70f2601b-03ae-47be-b34e-26cfb00c81c3

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