Detection rules › Splunk

Windows Suspicious C2 Named Pipe

Status
production
Severity
medium
Group by
PipeName, dest, dvc, process_guid, process_id, process_name, signature, signature_id, user_id, vendor_product
Author
Raven Tait, Splunk
Source
github.com/splunk/security_content

The following analytic detects the creation or connection to known suspicious C2 named pipes. It leverages Sysmon EventCodes 17 and 18 to identify known default pipe names used by C2 tools. If confirmed malicious, this could allow an attacker to abuse these to potentially gain persistence, command and control, or further system compromise.

Known false positives

  • False positives should be rare, investigate matches and apply additional filters as needed.

MITRE ATT&CK coverage

Telemetry coverage

Rule body

name: Windows Suspicious C2 Named Pipe
id: 90599d85-dc2a-4d4c-8c59-9485c3665828
version: 6
creation_date: '2025-12-08'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: TTP
description: |
    The following analytic detects the creation or connection to known suspicious C2 named pipes.
    It leverages Sysmon EventCodes 17 and 18 to identify known default pipe names used by C2 tools.
    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\\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 suspicious_c2_named_pipes suspicious_pipe_name AS pipe_name OUTPUT tool, description
    | where isnotnull(tool)
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_suspicious_c2_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: |
    False positives should be rare, investigate matches and apply additional filters as needed.
references:
    - https://attack.mitre.org/techniques/T1218/009/
    - https://docs.microsoft.com/en-us/windows/win32/ipc/named-pipes
finding:
    title: An instance of $process_name$ located in $process_path$ was identified on endpoint $dest$ accessing known suspicious C2 named pipe $pipe_name$.
    entity:
        field: dest
        type: system
        score: 50
threat_objects:
    - field: process_name
      type: process_name
analytic_story:
    - Storm-0501 Ransomware
    - APT37 Rustonotto and FadeStealer
    - BlackByte Ransomware
    - Brute Ratel C4
    - Cobalt Strike
    - DarkSide Ransomware
    - Gozi Malware
    - Graceful Wipe Out Attack
    - Hellcat Ransomware
    - LockBit Ransomware
    - Meterpreter
    - Remote Monitoring and Management Software
    - Trickbot
    - Tuoni
asset_type: Endpoint
mitre_attack_id:
    - T1559
    - T1021.002
    - T1055
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

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\\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 suspicious_c2_named_pipes suspicious_pipe_name AS pipe_name OUTPUT tool, description
Lookup table
suspicious_c2_named_pipes
Key field
suspicious_pipe_name as pipe_name
Output columns
['tool', 'tool'], ['description', '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_suspicious_c2_named_pipe_filter`

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
process_pathin"*:\\Program Files \(x86\)\\Adobe*", "*:\\Program Files \(x86\)\\Google*", "*:\\Program Files \(x86\)\\Microsoft*", "*:\\Program Files\\Adobe*", "*:\\Program Files\\Google*", "*:\\Program Files\\Microsoft*", "*:\\Windows\\System32\\svchost.exe", "*:\\Windows\\SystemApps\\Microsoft*", "*:\\Windows\\system32\\SearchIndexer.exe", "*\\Amazon\\SSM\\Instance*", "*\\AppData\\Local\\Google*", "*\\AppData\\Local\\Kingsoft\\*", "*\\AppData\\Local\\Microsoft*", "System"excludes:process_path

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
EventCodeeq
  • 17 corpus 5 (splunk 4, elastic 1)
  • 18 corpus 6 (splunk 4, chronicle 1, kusto 1)
field:"EventID" kind:eq
toolis_not_null
  • (no value, null check)
field:"tool" kind:is_not_null