Detection rules › Splunk
ESXi User Granted Admin Role
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.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | T1078 Valid Accounts |
| Persistence | T1078 Valid Accounts, T1098 Account Manipulation |
| Privilege Escalation | T1078 Valid Accounts, T1098 Account Manipulation |
| Stealth | T1078 Valid Accounts |
Rule body splunk
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
Stages and Predicates
Stage 1: search
`esxi_syslog` Message="*esxcli system permission set*" AND Message="*role Admin*"
Stage 2: rex
| rex field=_raw "\]: \[(?<user>\w+)\]:(?<command>.+)"
Stage 3: rex
| rex field=_raw "--id (?<target_user>\w+)"
Stage 4: rex
| rex field=_raw "Z (?<dest>[\w\.]+)\s"
Stage 5: stats
| stats min(_time) as firstTime max(_time) as lastTime count by dest user command target_user
Stage 6: search
| `security_content_ctime(firstTime)`
Stage 7: search
| `security_content_ctime(lastTime)`
Stage 8: search
| `esxi_user_granted_admin_role_filter`
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Message | eq |
|
sourcetype | in |
|