ESXi Sensitive Files Accessed

name: ESXi Sensitive Files Accessed
id: 6fa0073d-6ca0-4f93-913d-fb420c9de15b
version: 5
creation_date: '2025-07-11'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: TTP
description: This detection identifies access to sensitive system and configuration files on an ESXi host, including authentication data, service configurations, and VMware-specific management settings. Interaction with these files may indicate adversary reconnaissance, credential harvesting, or preparation for privilege escalation, lateral movement, or persistence.
data_source:
    - VMWare ESXi Syslog
search: '`esxi_syslog` Message="*shell[*" Message IN ("*/etc/shadow*","*/etc/vmware/hostd/hostd.xml*", "*/etc/vmware/vpxa/vpxa.cfg*","*/etc/sfcb/sfcb.cfg*","*/etc/security/*", "*/etc/likewise/krb5-affinity.conf*","*/etc/vmware-vpx/vcdb.properties*") | rex field=_raw "\]: \[(?<user>\w+)\]:(?<command>.+)" | rex field=_raw "Z (?<dest>[\w\.]+)\s" | stats min(_time) as firstTime max(_time) as lastTime count by dest user command | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `esxi_sensitive_files_accessed_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: Administrators may access these files for initial setup or troubleshooting. Limited in most environments. 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: Sensitive files accessed on ESXi host $dest$ with $command$.
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - ESXi Post Compromise
    - Black Basta Ransomware
    - China-Nexus Threat Activity
asset_type: Infrastructure
mitre_attack_id:
    - T1003.008
    - T1005
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/T1003.008/esxi_sensitive_files/esxi_sensitive_files.log
          source: vmware:esxlog
          sourcetype: vmw-syslog
      test_type: unit