Socat Remote TCP Connection with Local Echo Disabled

SPLUNK detection rule by Maria Jose Erquiaga, Splunk · Apache-2.0

The following analytic detects execution of the socat utility with a remote TCP or OpenSSL connection and local terminal echo disabled. This configuration may be used for interactive terminal sessions, password handling, automation, or network debugging. When observed in an unexpected context, such as execution by an unusual parent process or connection to an untrusted endpoint, it may indicate suspicious remote access activity.

name: Socat Remote TCP Connection with Local Echo Disabled
id: 458c6c37-116d-4f01-8267-f09f5b82cd14
version: 1
creation_date: '2026-08-27'
modification_date: '2026-08-27'
author: Maria Jose Erquiaga, Splunk
status: production
type: Anomaly
description: |-
    The following analytic detects execution of the socat utility with a remote TCP or OpenSSL connection and local terminal echo disabled.
    This configuration may be used for interactive terminal sessions, password handling, automation, or network debugging.
    When observed in an unexpected context, such as execution by an unusual parent process or connection to an untrusted endpoint, it may indicate suspicious remote access activity.
data_source:
    - Osquery Results
    - Sysmon for Linux EventID 1
search: |-
    | tstats `security_content_summariesonly`
      count min(_time) as firstTime
            max(_time) as lastTime

    from datamodel=Endpoint.Processes where

    Processes.process_name="socat*"
    Processes.process="*echo=0*"
    Processes.process IN (
        "*openssl:*",
        "*tcp:*",
        "*tcp4:*",
        "*tcp6:*"
    )

    by Processes.dest Processes.original_file_name Processes.parent_process_id
       Processes.process Processes.process_exec Processes.process_guid
       Processes.process_hash Processes.process_id
       Processes.process_current_directory 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)`
    | `socat_remote_tcp_connection_with_local_echo_disabled_filter`
how_to_implement: |-
    This detection uses osquery and endpoint security on MacOS. Follow the link in references, which describes how to setup process auditing in MacOS with endpoint security and osquery.
    Also the [TA-OSquery](https://splunkbase.splunk.com/app/8574) must be deployed across your indexers and universal forwarders in order to have the osquery data populate the data models.
known_false_positives: |-
    Developers and network engineers may use socat with local echo disabled for legitimate TCP debugging, protocol testing, terminal handling, or troubleshooting.
references:
    - https://attack.mitre.org/tactics/TA0002/
    - https://attack.mitre.org/techniques/T1059
    - https://blog.talosintelligence.com/bad-apples-weaponizing-native-macos-primitives-for-movement-and-execution/
    - https://gtfobins.github.io/gtfobins/socat/
    - https://hackers-arise.com/socat-the-advanced-hackers-network-tool/
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"
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: Socat was executed with local terminal echo disabled and a remote TCP or OpenSSL connection via Command Line [$process$] on endpoint [$dest$] by user [$user$].
threat_objects:
    - field: process
      type: process
analytic_story:
    - MacOS Post-Exploitation
asset_type: Endpoint
mitre_attack_id:
    - T1059
    - T1572
product:
    - Splunk Cloud
    - Splunk Enterprise
    - Splunk Enterprise Security
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/utility_socat_remote_tcp_connection_with_echo_disabled/osquery.log
          source: osquery
          sourcetype: osquery:results
      test_type: unit

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