First Time Seen Running Windows Service

name: First Time Seen Running Windows Service
id: 823136f2-d755-4b6d-ae04-372b486a5808
version: 12
creation_date: '2019-10-16'
modification_date: '2026-05-13'
author: David Dorsey, Splunk
status: experimental
type: Anomaly
description: The following analytic detects the first occurrence of a Windows service running in your environment. It leverages Windows system event logs, specifically EventCode 7036, to identify services entering the "running" state. This activity is significant because the appearance of a new or previously unseen service could indicate the installation of unauthorized or malicious software. If confirmed malicious, this activity could allow an attacker to execute arbitrary code, maintain persistence, or escalate privileges within the environment. Monitoring for new services helps in early detection of potential threats.
data_source:
    - Windows Event Log System 7036
search: |-
    `wineventlog_system` EventCode=7036
      | rex field=Message "The (?<service>[-\(\)\s\w]+) service entered the (?<state>\w+) state"
      | where state="running"
      | lookup previously_seen_running_windows_services service as service OUTPUT firstTimeSeen
      | where isnull(firstTimeSeen) OR firstTimeSeen > relative_time(now(), `previously_seen_windows_services_window`)
      | table _time dest service
      | `first_time_seen_running_windows_service_filter`
how_to_implement: While this search does not require you to adhere to Splunk CIM, you must be ingesting your Windows system event logs in order for this search to execute successfully. You should run the baseline search `Previously Seen Running Windows Services - Initial` to build the initial table of child processes and hostnames for this search to work. You should also schedule at the same interval as this search the second baseline search `Previously Seen Running Windows Services - Update` to keep this table up to date and to age out old Windows Services. Please update the `previously_seen_windows_services_window` macro to adjust the time window. Please ensure that the Splunk Add-on for Microsoft Windows is version 8.0.0 or above.
known_false_positives: A previously unseen service is not necessarily malicious. Verify that the service is legitimate and that was installed by a legitimate process.
references: []
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: Windows Service observed running for first time on $dest$
analytic_story:
    - Windows Service Abuse
    - Orangeworm Attack Group
    - NOBELIUM Group
asset_type: Endpoint
mitre_attack_id:
    - T1569.002
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
baselines:
    - Previously Seen Running Windows Services - Update
    - Previously Seen Running Windows Services - Initial