Linux Ingress Tool Transfer Hunting

Original Source: [splunk source]
Name:Linux Ingress Tool Transfer Hunting
id:52fd468b-cb6d-48f5-b16a-92f1c9bb10cf
version:5
date:2024-12-17
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.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
| `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
drilldown_searches:
  :
tags:
  analytic_story:
    - 'Ingress Tool Transfer'
    - 'Linux Living Off The Land'
    - 'XorDDos'
  asset_type:Endpoint
  confidence:10
  impact:10
  message:An instance of $process_name$ was identified on endpoint $dest$ by user $user$ utilizing curl or wget.
  mitre_attack_id:
    - 'T1105'
  observable:
    name:'user'
    type:'User'
    - role:
      - 'Victim'
    name:'dest'
    type:'Hostname'
    - role:
      - 'Victim'
    name:'process_name'
    type:'Process'
    - role:
      - 'Attacker'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  required_fields:
    - '_time'
    - 'Processes.dest'
    - 'Processes.user'
    - 'Processes.parent_process_name'
    - 'Processes.parent_process'
    - 'Processes.original_file_name'
    - 'Processes.process_name'
    - 'Processes.process'
    - 'Processes.process_id'
    - 'Processes.parent_process_path'
    - 'Processes.process_path'
    - 'Processes.parent_process_id'
  risk_score:1
  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
  update_timestamp: True
manual_test:None