PTC Windchill GW READY OK Probe
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.
Query · spl
`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`
Implementation guide
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.
Analyst notes
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.