Detection rules › Splunk

Detect Prohibited Applications Spawning cmd exe

Status
production
Group by
IntegrityLevel, command_line, computer_name, event_action, original_file_name, parent_command_line, parent_process_guid, parent_process_id, parent_process_name, process_guid, process_hash, process_id, process_name, user, user_id, vendor_product
Author
Bhavin Patel, Splunk
Source
github.com/splunk/security_content

The following analytic detects executions of cmd.exe spawned by processes that are commonly abused by attackers and do not typically launch cmd.exe. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process GUID, process name, parent process, and command-line executions. This activity is significant because it may indicate an attempt to execute unauthorized commands or scripts, often a precursor to further malicious actions. If confirmed malicious, this behavior could lead to unauthorized code execution, privilege escalation, or persistence within the environment.

MITRE ATT&CK coverage

Event coverage

Rule body splunk

name: Detect Prohibited Applications Spawning cmd exe
id: dcfd6b40-42f9-469d-a433-2e53f7486664
version: 16
creation_date: '2020-04-29'
modification_date: '2026-05-13'
author: Bhavin Patel, Splunk
status: production
type: Hunting
description: The following analytic detects executions of cmd.exe spawned by processes that are commonly abused by attackers and do not typically launch cmd.exe. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process GUID, process name, parent process, and command-line executions. This activity is significant because it may indicate an attempt to execute unauthorized commands or scripts, often a precursor to further malicious actions. If confirmed malicious, this behavior could lead to unauthorized code execution, privilege escalation, or persistence within the environment.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
search: |
    | tstats `security_content_summariesonly` count values(Processes.process)
    as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name=cmd.exe OR Processes.original_file_name=Cmd.Exe)
    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
    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    |search [
        | inputlookup prohibited_apps_launching_cmd
        | rename prohibited_applications as parent_process_name
        | eval parent_process_name="*" . parent_process_name
        | table parent_process_name
      ]
    | `detect_prohibited_applications_spawning_cmd_exe_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: There are circumstances where an application may legitimately execute and interact with the Windows command-line interface. Investigate and modify the lookup file, as appropriate.
references: []
analytic_story:
    - Suspicious Command-Line Executions
    - Suspicious MSHTA Activity
    - Suspicious Zoom Child Processes
    - NOBELIUM Group
asset_type: Endpoint
mitre_attack_id:
    - T1059.003
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/T1059.003/powershell_spawn_cmd/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

Stages and Predicates

Stage 1: tstats

| tstats `security_content_summariesonly` count values(Processes.process)
as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name=cmd.exe OR Processes.original_file_name=Cmd.Exe)
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

| search [
    | inputlookup prohibited_apps_launching_cmd
    | rename prohibited_applications as parent_process_name
    | eval parent_process_name="*" . parent_process_name
    | table parent_process_name
  ]

Stage 6: search

| `detect_prohibited_applications_spawning_cmd_exe_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.

FieldKindValues
1eq
  • 1 corpus 7 (splunk 7)
Processes.original_file_nameeq
  • "Cmd.Exe" corpus 65 (sigma 43, splunk 17, elastic 5)
Processes.process_nameeq
  • "cmd.exe" corpus 77 (elastic 48, splunk 29)