ESXi User Granted Admin Role

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

This detection identifies when a user is granted the Administrator role on an ESXi host. Assigning elevated privileges is a critical action that can indicate potential malicious behavior if performed unexpectedly. Adversaries who gain access may use this to escalate privileges, maintain persistence, or disable security controls.

name: ESXi User Granted Admin Role
id: b0c64d6e-cfdf-441a-b6ce-d956e202563e
version: 4
creation_date: '2025-07-11'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: TTP
description: This detection identifies when a user is granted the Administrator role on an ESXi host. Assigning elevated privileges is a critical action that can indicate potential malicious behavior if performed unexpectedly. Adversaries who gain access may use this to escalate privileges, maintain persistence, or disable security controls.
data_source:
    - VMWare ESXi Syslog
search: '`esxi_syslog` Message="*esxcli system permission set*" AND Message="*role Admin*" | rex field=_raw "\]: \[(?<user>\w+)\]:(?<command>.+)" | rex field=_raw "--id (?<target_user>\w+)" | rex field=_raw "Z (?<dest>[\w\.]+)\s" | stats min(_time) as firstTime max(_time) as lastTime count by dest user command target_user | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `esxi_user_granted_admin_role_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 after initial setup, 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: $target_user$ granted Admin role on ESXi host $dest$ by $user$.
    entity:
        field: target_user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: $target_user$ granted Admin role on ESXi host $dest$ by $user$.
analytic_story:
    - ESXi Post Compromise
    - Black Basta Ransomware
asset_type: Infrastructure
mitre_attack_id:
    - T1098
    - T1078
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/T1098/esxi_admin_role/esxi_admin_role.log
          source: vmware:esxlog
          sourcetype: vmw-syslog
      test_type: unit

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

5e153bb0-25ce-4912-9bd4-32ae6f0c021c

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Executable code, not a declarative rule

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Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

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