Windows PuTTY Suite Utility Execution

name: Windows PuTTY Suite Utility Execution
id: 64d5263e-0f29-4641-81ed-03b39c27ecd4
version: 2
creation_date: '2026-05-05'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: Anomaly
description: |-
    This analytic detects the execution of programs associated with the PuTTY SSH client suite, including putty.exe, pscp.exe, plink.exe, psftp.exe, and puttygen.exe.
    This activity is significant because these tools can be used to establish unauthorized remote connections, transfer files, or execute commands on remote systems.
    If identified in an unusual context, such as non-administrative accounts or unexpected systems, it may indicate attempts to bypass security controls, perform lateral movement, or exfiltrate data, which could lead to further network compromise.
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_name IN (
            "putty.exe",
            "pscp.exe",
            "plink.exe",
            "psftp.exe",
            "puttygen.exe"
        )
        OR
        Processes.original_file_name IN (
            "PuTTY",
            "PSCP",
            "Plink",
            "PSFTP",
            "PuTTYgen"
        )
    )
    
    by Processes.process Processes.vendor_product Processes.user_id
       Processes.process_hash Processes.parent_process_name
       Processes.parent_process_exec Processes.action Processes.dest
       Processes.process_current_directory Processes.process_path
       Processes.process_integrity_level Processes.original_file_name
       Processes.parent_process Processes.parent_process_path
       Processes.parent_process_guid Processes.parent_process_id
       Processes.process_guid Processes.process_id
       Processes.user Processes.process_name
    
    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_putty_suite_utility_execution_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: Some legitimate users may run PuTTY for remote administration or secure file transfers. Filter alerts to exclude approved administrative activities.
drilldown_searches:
    - earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
      name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
    - name: View risk events for the last 7 days for - "$user$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") | 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: Potential PuTTY suite activity observed on $dest$ via $process$.
threat_objects:
    - field: parent_process_name
      type: parent_process_name
analytic_story:
    - Command And Control
    - Active Directory Lateral Movement
asset_type: Endpoint
mitre_attack_id:
    - T1021.004
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/T1021.004/snapattack/snapattack.log
          source: XmlWinEventLog:Security
          sourcetype: XmlWinEventLog
      test_type: unit