Cisco NVM - Osascript Network Connection for a Long Duration

name: Cisco NVM - Osascript Network Connection for a Long Duration
id: 6bc88a9d-f7de-4257-b526-acf15bc5a517
version: 1
creation_date: '2026-09-18'
modification_date: '2026-09-18'
author: Radka Viskova, Splunk
status: production
type: Anomaly
description: |-
    This analytic detects the usage of the Utility osascript on a macOS device initiated a network connection lasting longer than 10 minutes (600 seconds).
    Adversaries may abuse osascript and AppleScript shell execution to establish long-lived command-and-control or remote connections.
data_source:
    - Cisco Network Visibility Module Flow Data
search: |-
    `cisco_network_visibility_module_flowdata`
    (
        parent_process_name="osascript"
        OR
        process_name="osascript"
    )

    ```
    FSS stands for Flow Start Seconds
    FES stands for Flow End Seconds
    ```
    | eval duration=fes-fss

    | where duration>600

    | stats count min(_time) as firstTime
                  max(_time) as lastTime
                  values(parent_process_hash) as parent_process_hash
                  values(process_hash) as process_hash
                  values(dest_port) as dest_port
                  values(dest_hostname) as dest_hostname
                  values(http_method) as http_method
    by src dest transport parent_process_path parent_process_name
       parent_process parent_process_id process_path process_name
       process process_id user duration

    | eval duration=tostring(duration)." seconds"

    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `cisco_nvm___osascript_network_connection_for_a_long_duration_filter`
how_to_implement: |-
    This search requires Network Visibility Module logs, which includes the flow data sourcetype.
    This search uses an input macro named `cisco_network_visibility_module_flowdata`.
    We strongly recommend that you specify your environment-specific configurations
    (index, source, sourcetype, etc.) for Cisco Network Visibility Module logs.
    Replace the macro definition with configurations for your Splunk environment.
    The search also uses a post-filter macro designed to filter out known false positives.
    The logs are to be ingested using the Splunk Add-on for Cisco Endpoint Security Analytics (CESA) (https://splunkbase.splunk.com/app/4221).
known_false_positives: |-
    Legitimate administrative scripting, automation, software deployment, or support workflows that use osascript for long-running network operations.
references:
    - https://attack.mitre.org/tactics/TA0002/
    - https://attack.mitre.org/tactics/TA0011/
    - https://attack.mitre.org/techniques/T1059/002/
    - https://attack.mitre.org/techniques/T1071/001/
    - https://www.loobins.io/binaries/osascript/
drilldown_searches:
    - name: View detection results for "$src$" and "$dest$"
      search: '%original_detection_search% | search src="$src$" dest="$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for "$src$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$src$", "$dest$") | 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" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
intermediate_findings:
    entities:
        - field: src
          type: system
          score: 20
          message: The macOS host [$src$] used the Osascript utility with the command line [$process$] and a parent process [$parent_process_name$] to initiate a network connection to [$dest$] lasting [$duration$].
threat_objects:
    - field: parent_process_name
      type: process_name
    - field: process_name
      type: process_name
    - field: dest
      type: ip_address
analytic_story:
    - Command And Control
    - Cisco Network Visibility Module Analytics
    - MacOS Post-Exploitation
asset_type: Endpoint
mitre_attack_id:
    - T1059.002
    - T1071.001
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/refs/heads/master/datasets/attack_techniques/T1059.002/osascript_long_lived_connection_to_remote_host/osascript_long_lived_connection_to_remote_host.log
          source: not_applicable
          sourcetype: cisco:nvm:flowdata:v2
      test_type: unit