Detection rules › Splunk
Windows PUA Named Pipe
The following analytic detects the creation or connection to named pipes used by potentially unwanted applications (PUAs) like VPNs or utilities like PsExec. It leverages Sysmon EventCodes 17 and 18. If confirmed malicious, this could allow an attacker to abuse these to potentially gain persistence, command and control, or further system compromise.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1559 Inter-Process Communication |
| Privilege Escalation | T1055 Process Injection |
| Stealth | T1055 Process Injection |
| Lateral Movement | T1021.002 Remote Services: SMB/Windows Admin Shares |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 17 | PipeEvent (Pipe Created) |
| Sysmon | Event ID 18 | PipeEvent (Pipe Connected) |
Rule body splunk
name: Windows PUA Named Pipe
id: 95b11d20-e2c6-46a5-b526-8629f5f0860a
version: 5
creation_date: '2025-12-08'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: Anomaly
description: |
The following analytic detects the creation or connection to named pipes used by potentially unwanted applications (PUAs) like VPNs or utilities like PsExec.
It leverages Sysmon EventCodes 17 and 18.
If confirmed malicious, this could allow an attacker to abuse these to potentially gain persistence, command and control, or further system compromise.
data_source:
- Sysmon EventID 17
- Sysmon EventID 18
search: |
`sysmon`
(EventCode=17 OR EventCode=18)
NOT process_path IN (
"*:\\Program Files \(x86\)\\Adobe*",
"*:\\Program Files \(x86\)\\Google*",
"*:\\Program Files \(x86\)\\Microsoft*",
"*:\\Program Files\\Adobe*",
"*:\\Program Files\\dotnet\\dotnet.exe",
"*:\\Program Files\\Google*",
"*:\\Program Files\\Microsoft*",
"*:\\Windows\\system32\\SearchIndexer.exe",
"*:\\Windows\\System32\\svchost.exe",
"*:\\Windows\\SystemApps\\Microsoft*",
"*\\Amazon\\SSM\\Instance*",
"*\\AppData\\Local\\Google*",
"*\\AppData\\Local\\Kingsoft\\*",
"*\\AppData\\Local\\Microsoft*",
"System"
)
| stats min(_time) as firstTime max(_time) as lastTime
count by dest dvc process_exec process_guid process_id process_path signature signature_id
vendor_product pipe_name user_id Image process_name
| lookup pua_named_pipes pua_pipe_name AS pipe_name OUTPUT tool, description
| where isnotnull(tool)
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_pua_named_pipe_filter`
how_to_implement: |
To successfully implement this search, you need to be ingesting
logs with the process name and pipename from your endpoints. If you are using Sysmon,
you must have at least version 6.0.4 of the Sysmon TA.
known_false_positives: |
PUAs can be used in a legitimate manner. Therefore, some of the named pipes identified and added may cause false positives.
Filter by process name or pipe name to reduce false positives.
references:
- https://attack.mitre.org/techniques/T1218/009/
- https://docs.microsoft.com/en-us/windows/win32/ipc/named-pipes
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: An instance of $process_name$ located in $process_path$ was identified on endpoint $dest$ accessing known named pipe $pipe_name$ from a potentially unwanted application in your environment.
threat_objects:
- field: process_name
type: process_name
analytic_story:
- Active Directory Lateral Movement
- BlackByte Ransomware
- Cactus Ransomware
- CISA AA22-320A
- DarkGate Malware
- DarkSide Ransomware
- DHS Report TA18-074A
- HAFNIUM Group
- IcedID
- Medusa Ransomware
- Rhysida Ransomware
- SamSam Ransomware
- Sandworm Tools
- Seashell Blizzard
- VanHelsing Ransomware
- Volt Typhoon
asset_type: Endpoint
mitre_attack_id:
- T1559
- T1021.002
- T1055
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/T1055/named_pipes/windows-sysmon.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: XmlWinEventLog
test_type: unit
Stages and Predicates
Stage 1: search
`sysmon`
(EventCode=17 OR EventCode=18)
NOT process_path IN (
"*:\\Program Files \(x86\)\\Adobe*",
"*:\\Program Files \(x86\)\\Google*",
"*:\\Program Files \(x86\)\\Microsoft*",
"*:\\Program Files\\Adobe*",
"*:\\Program Files\\dotnet\\dotnet.exe",
"*:\\Program Files\\Google*",
"*:\\Program Files\\Microsoft*",
"*:\\Windows\\system32\\SearchIndexer.exe",
"*:\\Windows\\System32\\svchost.exe",
"*:\\Windows\\SystemApps\\Microsoft*",
"*\\Amazon\\SSM\\Instance*",
"*\\AppData\\Local\\Google*",
"*\\AppData\\Local\\Kingsoft\\*",
"*\\AppData\\Local\\Microsoft*",
"System"
)
Stage 2: stats
| stats min(_time) as firstTime max(_time) as lastTime
count by dest dvc process_exec process_guid process_id process_path signature signature_id
vendor_product pipe_name user_id Image process_name
Stage 3: lookup
| lookup pua_named_pipes pua_pipe_name AS pipe_name OUTPUT tool, description
Stage 4: where
| where isnotnull(tool)
Stage 5: search
| `security_content_ctime(firstTime)`
Stage 6: search
| `security_content_ctime(lastTime)`
Stage 7: search
| `windows_pua_named_pipe_filter`
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
process_path | in | "*:\\Program Files \(x86\)\\Adobe*", "*:\\Program Files \(x86\)\\Google*", "*:\\Program Files \(x86\)\\Microsoft*", "*:\\Program Files\\Adobe*", "*:\\Program Files\\Google*", "*:\\Program Files\\Microsoft*", "*:\\Program Files\\dotnet\\dotnet.exe", "*:\\Windows\\System32\\svchost.exe", "*:\\Windows\\SystemApps\\Microsoft*", "*:\\Windows\\system32\\SearchIndexer.exe", "*\\Amazon\\SSM\\Instance*", "*\\AppData\\Local\\Google*", "*\\AppData\\Local\\Kingsoft\\*", "*\\AppData\\Local\\Microsoft*", "System" |
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.