PTC Windchill GW READY OK Probe

name: PTC Windchill GW READY OK Probe
id: 2f37ab99-5eae-44c4-a6bc-15b6d9787a3d
version: 1
creation_date: '2026-06-14'
modification_date: '2026-06-14'
author: Nasreddine Bencherchali, Splunk
status: production
type: Anomaly
description: |
    This analytic detects Windchill MethodServer log4j events that contain the CVE-2026-4681 exploitation probe `run?c=echo%20GW_READY_OK`.
    PTC identifies `GW_READY_OK` and related `run?c=` activity as log indicators associated with Windchill and FlexPLM exploitation.
    This behavior is significant because attackers use the probe to confirm that a staged gateway component is reachable before sending operating system commands through the same `c=` parameter.
data_source:
    - Windchill Log4j
search: |-
    `windchill_log4j`
    ("GW_READY_OK" OR "run?c=echo%20GW_READY_OK" OR "c=echo%20GW_READY_OK")
    | rex field=_raw "^(?:[^:\r\n]+:)?(?<log_ts>\d{4}-\d{2}-\d{2}\s+\d{2}:\d{2}:\d{2},\d{3})\s+(?<log_level>\w+)\s+\[(?<thread>[^\]]+)\]\s+(?<logger>\S+)\s+-\s+(?<payload>.*)$"
    | search logger IN ("wt.servlet.ServletRequestMonitor.request", "wt.method.MethodContextMonitor.contexts.servletRequest")
    | rex field=payload "^(?<event_ts>\d{4}-\d{2}-\d{2}\s+\d{2}:\d{2}:\d{2}\.\d{3})\s+(?<event_tz>[+\-]\d{4}),\s+(?<rest>.*)$"
    | eval parts=split(rest,", ")
    | eval event_type=case(logger="wt.servlet.ServletRequestMonitor.request","servlet_request",logger="wt.method.MethodContextMonitor.contexts.servletRequest","method_context_servlet_request",true(),"other")
    | eval src_ip=case(event_type="servlet_request",mvindex(parts,2),event_type="method_context_servlet_request",mvindex(parts,5))
    | eval uri_path=case(event_type="servlet_request",mvindex(parts,3),event_type="method_context_servlet_request",mvindex(parts,8))
    | eval query_string=if(event_type="servlet_request",mvindex(parts,4),null())
    | eval http_method=if(event_type="servlet_request",mvindex(parts,5),null())
    | eval status=if(event_type="servlet_request",tonumber(mvindex(parts,6)),null())
    | rex field=uri_path "^(?<uri_only>[^\?]+)(?:\?(?<uri_query>.*))?$"
    | eval query_string=if(query_string="-",null(),query_string)
    | eval query_string=coalesce(query_string,uri_query)
    | rex field=query_string "(?i)(?:^|&)(?<query_param>[cp])=(?<query_value>[^&]*)"
    | eval query_param=lower(query_param), query_value=urldecode(replace(query_value,"\+","%20"))
    | where query_param="c" AND match(query_value,"(?i)^echo(\s|20)+GW_READY_OK$")
    | eval src=src_ip, activity="gw_ready_ok_probe"

    | stats count min(_time) as firstTime
                  max(_time) as lastTime
                  values(log_level) as log_level
                  values(logger) as logger
                  values(http_method) as http_method
                  values(status) as status
                  values(uri_only) as uri_path
                  values(query_string) as query_string
      by src activity query_param query_value

    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `ptc_windchill_gw_ready_ok_probe_filter`
how_to_implement: |
    To implement this analytic, ingest PTC Windchill MethodServer log4j logs into Splunk with sourcetype `log4j`.
    Update the `windchill_log4j` macro to include the appropriate index constraints for your environment.
    The analytic expects log entries from the `wt.servlet.ServletRequestMonitor.request` and `wt.method.MethodContextMonitor.contexts.servletRequest` loggers.
known_false_positives: |
    This probe string is specific to the PTC-published Windchill exploitation indicators. False positives should be rare. Validate whether any internal testing, incident response activity, or vendor diagnostics intentionally generated `GW_READY_OK` requests.
references:
    - https://www.ptc.com/en/about/trust-center/advisory-center/active-advisories/windchill-flexplm-critical-vulnerability
    - https://nvd.nist.gov/vuln/detail/CVE-2026-4681
    - https://www.cisa.gov/news-events/ics-advisories/icsa-26-085-03
drilldown_searches:
    - name: View the detection results for - "$src$"
      search: '%original_detection_search% | search src = "$src$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$src$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$src$") | 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: src
          type: system
          score: 20
          message: PTC Windchill GW READY OK exploitation probe detected from $src$.
threat_objects:
    - field: src
      type: ip_address
analytic_story:
    - PTC Windchill Exploitation
asset_type: Web Application
cve:
    - CVE-2026-4681
mitre_attack_id:
    - T1190
    - T1059
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: application
security_domain: network
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/emerging_threats/windchill/windchill_exploitation.log
          source: not_applicable
          sourcetype: log4j
      test_type: unit