Windows Process Accessing IronLanguages Repository On GitHub


Description

The following analytic identifies a process command line referencing the IronLanguages GitHub repository, which hosts .NET implementation of popular scripting engines. Adversaries have downloaded these .NET implementations to avoid getting detected by security controls while executing their payloads. This activity is uncommon in typical enterprise environments outside of software development contexts.

Query · spl

| tstats `security_content_summariesonly`
  count min(_time) as firstTime
        max(_time) as lastTime
FROM datamodel=Endpoint.Processes WHERE

Processes.process="*/ironlanguages/*"
Processes.process="*github.com*"

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)`
| `windows_process_accessing_ironlanguages_repository_on_github_filter`

Implementation guide

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

  • Software developers or DevOps personnel may legitimately clone or download the IronPython repository from GitHub for development purposes. Filter as needed based on known developer hosts or users in your environment.

Analyst notes

Known false positives: Software developers or DevOps personnel may legitimately clone or download the IronPython repository from GitHub for development purposes. Filter as needed based on known developer hosts or users in your environment.

Raw source Windows Process Accessing IronLanguages Repository On GitHub · SPL
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Published by splunk/security_content ↗, licensed under Apache 2.0 ↗. Reproduced here unmodified.
name: Windows Process Accessing IronLanguages Repository On GitHub
id: bcdc2543-8c33-44c8-a723-5b7b93e06788
version: 1
creation_date: '2026-09-16'
modification_date: '2026-09-16'
author: Onur Mustafa Erdogan, Splunk
status: production
type: Anomaly
description: |-
    The following analytic identifies a process command line referencing the IronLanguages GitHub repository, which hosts .NET implementation of popular scripting engines.
    Adversaries have downloaded these .NET implementations to avoid getting detected by security controls while executing their payloads.
    This activity is uncommon in typical enterprise environments outside of software development contexts.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
search: |-
    | tstats `security_content_summariesonly`
      count min(_time) as firstTime
            max(_time) as lastTime
    FROM datamodel=Endpoint.Processes WHERE

    Processes.process="*/ironlanguages/*"
    Processes.process="*github.com*"

    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)`
    | `windows_process_accessing_ironlanguages_repository_on_github_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: |-
    Software developers or DevOps personnel may legitimately clone or download the IronPython repository from GitHub for development purposes.
    Filter as needed based on known developer hosts or users in your environment.
references:
    - https://packetwatch.com/resources/threat-profile/clickfix-abuses-finger-to-deliver-castleloader
    - https://github.com/IronLanguages/ironpython3
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: The Process [$process_name$] with the Command Line [$process$] accessed the IronLanguages GitHub repository on [$dest$].
threat_objects:
    - field: process
      type: process
analytic_story:
    - Compromised Windows Host
    - Fake CAPTCHA Campaigns
    - Ingress Tool Transfer
    - Windows Post-Exploitation
asset_type: Endpoint
mitre_attack_id:
    - T1059
    - T1105
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/master/datasets/attack_techniques/T1105/ironlanguage_download/ironlanguage_download.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

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