splunk_escuTTP

ESXi Encryption Settings Modified

Detects the disabling of critical encryption enforcement settings on an ESXi host, such as secure boot or executable verification requirements, which may indicate an attempt to weaken hypervisor integrity or allow unauthorized code execution.

MITRE ATT&CK

T1562

Detection Query

`esxi_syslog` Message="*system settings encryption set*" NOT Message="*shell.*" Message IN ("* -s *", "* -e *","*--require-secure-boot*", "*require-exec-installed-only*", "execInstalledOnly") | rex field=_raw "Z (?<dest>[\w\.]*)\s.*\]: \[(?<user>\w+)\]:(?<command>.+)" | stats min(_time) as firstTime max(_time) as lastTime count by dest user command | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `esxi_encryption_settings_modified_filter`

Author

Raven Tait, Splunk

Created

2026-03-10

Data Sources

VMWare ESXi Syslog

Tags

ESXi Post CompromiseBlack Basta Ransomware

Raw Content

name: ESXi Encryption Settings Modified
id: dbbbe26f-83fe-4ee3-8b77-ccf7fbd416c8
version: 2
date: '2026-03-10'
author: Raven Tait, Splunk
status: production
type: TTP
description: Detects the disabling of critical encryption enforcement settings on an ESXi host, such as secure boot or executable verification requirements, which may indicate an attempt to weaken hypervisor integrity or allow unauthorized code execution.
data_source:
    - VMWare ESXi Syslog
search: '`esxi_syslog` Message="*system settings encryption set*" NOT Message="*shell.*" Message IN ("* -s *", "* -e *","*--require-secure-boot*", "*require-exec-installed-only*", "execInstalledOnly") | rex field=_raw "Z (?<dest>[\w\.]*)\s.*\]: \[(?<user>\w+)\]:(?<command>.+)" | stats min(_time) as firstTime max(_time) as lastTime count by dest user command | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `esxi_encryption_settings_modified_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 ("$dest$") starthoursago=168  | 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: $info_min_time$
      latest_offset: $info_max_time$
rba:
    message: Encryption settings modified on ESXi host $dest$.
    risk_objects:
        - field: dest
          type: system
          score: 50
    threat_objects: []
tags:
    analytic_story:
        - ESXi Post Compromise
        - Black Basta Ransomware
    asset_type: Infrastructure
    mitre_attack_id:
        - T1562
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    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_encryption_modified/esxi_encryption_modified.log
          source: vmware:esxlog
          sourcetype: vmw-syslog