Detection rules › Splunk
Windows Suspicious VMWare Tools Child Process
The following analytic identifies child processes spawned by vmtoolsd.exe, the VMWare Tools service in Windows, which typically runs with SYSTEM privileges. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and parent process relationships. Monitoring this activity is crucial as it can indicate exploitation attempts, such as CVE-2023-20867. If confirmed malicious, attackers could gain SYSTEM-level access, allowing them to execute arbitrary code, escalate privileges, and potentially compromise the entire system.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1059 Command and Scripting Interpreter |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body splunk
name: Windows Suspicious VMWare Tools Child Process
id: 1f77661a-0fe3-4b8d-a62c-7dff06906d26
version: 5
creation_date: '2022-02-09'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: TTP
description: The following analytic identifies child processes spawned by vmtoolsd.exe, the VMWare Tools service in Windows, which typically runs with SYSTEM privileges. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and parent process relationships. Monitoring this activity is crucial as it can indicate exploitation attempts, such as CVE-2023-20867. If confirmed malicious, attackers could gain SYSTEM-level access, allowing them to execute arbitrary code, escalate privileges, and potentially compromise the entire system.
data_source:
- Sysmon EventID 1
- Windows Event Log Security 4688
- CrowdStrike ProcessRollup2
search: "| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes\n WHERE Processes.parent_process_name=vmtoolsd.exe\n AND\n Processes.process_name IN (\"powershell.exe\",\"cmd.exe\", \"msbuild.exe\", \"microsoft.workflow.compiler.exe\", \"searchprotocolhost.exe\", \"scrcons.exe\", \"cscript.exe\", \"wscript.exe\",\"bitsadmin.exe\", \"rundll32.exe\", \"wmic.exe\", \"mshta.exe\", \"certutil.exe\", \"schtasks.exe\")\n AND NOT\n (Processes.process_name=\"cmd.exe\" AND Processes.process IN (\"*\\\\VMware Tools\\\\poweroff-vm-default.bat*\",\"*\\\\VMware Tools\\\\poweron-vm-default.bat*\"))\n BY Processes.action Processes.dest Processes.original_file_name\n Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid\n Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path\n Processes.process Processes.process_exec Processes.process_guid\n Processes.process_hash Processes.process_id Processes.process_integrity_level\n Processes.process_name Processes.process_path Processes.user\n Processes.user_id Processes.vendor_product\n| `drop_dm_object_name(Processes)`\n| `security_content_ctime(firstTime)`\n| `security_content_ctime(lastTime)`\n| `windows_suspicious_vmware_tools_child_process_filter`"
how_to_implement: The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives: Although unlikely, some legitimate Administrative scripts may utilize VMWare Tools to execute commands on virtual machines.
references:
- https://cloud.google.com/blog/topics/threat-intelligence/vmware-esxi-zero-day-bypass/
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: Suspicious process spawned by vmtoolsd.exe on $dest$
entity:
field: dest
type: system
score: 50
threat_objects:
- field: parent_process_name
type: parent_process_name
analytic_story:
- ESXi Post Compromise
- China-Nexus Threat Activity
asset_type: Endpoint
cve:
- CVE-2023-20867
mitre_attack_id:
- T1059
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1059/vmtoolsd/vmtoolsd_execution.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: XmlWinEventLog
test_type: unit
Stages and Predicates
Stage 1: tstats
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
WHERE Processes.parent_process_name=vmtoolsd.exe
AND
Processes.process_name IN ("powershell.exe","cmd.exe", "msbuild.exe", "microsoft.workflow.compiler.exe", "searchprotocolhost.exe", "scrcons.exe", "cscript.exe", "wscript.exe","bitsadmin.exe", "rundll32.exe", "wmic.exe", "mshta.exe", "certutil.exe", "schtasks.exe")
AND NOT
(Processes.process_name="cmd.exe" AND Processes.process IN ("*\\VMware Tools\\poweroff-vm-default.bat*","*\\VMware Tools\\poweron-vm-default.bat*"))
BY Processes.action Processes.dest Processes.original_file_name
Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
Processes.process Processes.process_exec Processes.process_guid
Processes.process_hash Processes.process_id Processes.process_integrity_level
Processes.process_name Processes.process_path Processes.user
Processes.user_id Processes.vendor_product
Stage 2: search
| `drop_dm_object_name(Processes)`
Stage 3: search
| `security_content_ctime(firstTime)`
Stage 4: search
| `security_content_ctime(lastTime)`
Stage 5: search
| `windows_suspicious_vmware_tools_child_process_filter`
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
Processes.process | in | "*\\VMware Tools\\poweroff-vm-default.bat*", "*\\VMware Tools\\poweron-vm-default.bat*" |
Processes.process_name | eq | "cmd.exe" |
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 |
|---|---|---|
Processes.parent_process_name | eq |
|
Processes.process_name | in |
|