Linux Ingress Tool Transfer Hunting

name: Linux Ingress Tool Transfer Hunting
id: 52fd468b-cb6d-48f5-b16a-92f1c9bb10cf
version: 11
date: '2026-03-31'
author: Michael Haag, Splunk
status: production
type: Hunting
description: The following analytic detects the use of 'curl' and 'wget' commands within a Linux environment. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, user information, and command-line executions. This activity is significant as 'curl' and 'wget' are commonly used for downloading files, which can indicate potential ingress of malicious tools. If confirmed malicious, this activity could lead to unauthorized code execution, data exfiltration, or further compromise of the system. Monitoring and tuning this detection helps identify and differentiate between normal and potentially harmful usage.
data_source:
    - 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=curl
            OR
            Processes.process_name=wget
        )
      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)`
    | `linux_ingress_tool_transfer_hunting_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: False positives will be present. This query is meant to help tune other curl and wget analytics.
references:
    - https://gtfobins.github.io/gtfobins/curl/
    - https://curl.se/docs/manpage.html#-I
    - https://gtfobins.github.io/gtfobins/curl/
    - https://github.com/rapid7/metasploit-framework/search?q=curl
tags:
    analytic_story:
        - Ingress Tool Transfer
        - Linux Living Off The Land
        - XorDDos
        - NPM Supply Chain Compromise
        - Axios Supply Chain Post Compromise
    asset_type: Endpoint
    mitre_attack_id:
        - T1105
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1105/atomic_red_team/curl-linux-sysmon.log
          source: Syslog:Linux-Sysmon/Operational
          sourcetype: sysmon:linux