name: ESXi SSH Enabled
id: b8003567-c5b6-445b-8966-ecdacc81c24d
version: 2
date: '2025-10-14'
author: Raven Tait, Splunk
status: production
type: TTP
description: This detection identifies SSH being enabled on ESXi hosts, which can be an early indicator of 
  malicious activity. Threat actors often use SSH to gain persistent remote access after compromising credentials
  or exploiting vulnerabilities.
data_source:
- VMWare ESXi Syslog
search: '`esxi_syslog` Message="*SSH access 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_ssh_enabled_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. Some Administrators may use SSH for troubleshooting.
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: SSH was enabled on ESXi host $dest$.
  risk_objects:
  - field: dest
    type: system
    score: 50
  threat_objects: []
tags:
  analytic_story:
  - ESXi Post Compromise
  - Black Basta Ransomware
  - Hellcat Ransomware
  asset_type: Infrastructure
  mitre_attack_id:
  - T1021.004
  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/T1021.004/esxi_ssh_enabled/esxi_ssh_enabled.log
    source: vmware:esxlog
    sourcetype: vmw-syslog