LOLBAS Rare Network Connection

Description

The following analytic identifies public network connections initiated by Living Off the Land Binaries and Scripts (LOLBAS) that rarely require direct outbound network access. It leverages the Network Traffic data model and focuses on native Windows binaries where any public destination should be investigated and explicitly approved. This activity may indicate proxy execution, process injection, payload download, command-and-control, or other abuse of trusted binaries to evade security controls. Keep in mind that some of these binaries, such as Netsh.exe, Gpscript.exe, Wmic.exe, etc., will occasionally communicate with public network resources to perform their intended function. Exclude said processes from the detection if they are too noisy for your environment. Join this detection with the Process Execution events to provide context and avoid false positives.

Query · spl

| tstats `security_content_summariesonly`
  count min(_time) as firstTime
        max(_time) as lastTime

from datamodel=Network_Traffic.All_Traffic where

All_Traffic.app IN (
    "*\\at.exe",
    "*\\atbroker.exe",
    "*\\certoc.exe",
    "*\\diskshadow.exe",
    "*\\dnscmd.exe",
    "*\\extexport.exe",
    "*\\forfiles.exe",
    "*\\gpscript.exe",
    "*\\infdefaultinstall.exe",
    "*\\installutil.exe",
    "*\\makecab.exe",
    "*\\mavinject.exe",
    "*\\microsoft.workflow.compiler.exe",
    "*\\msconfig.exe",
    "*\\netsh.exe",
    "*\\notepad.exe",
    "*\\odbcconf.exe",
    "*\\offlinescannershell.exe",
    "*\\pcalua.exe",
    "*\\pcwrun.exe",
    "*\\pnputil.exe",
    "*\\rasautou.exe",
    "*\\regasm.exe",
    "*\\register-cimprovider.exe",
    "*\\regsvcs.exe",
    "*\\regsvr32.exe",
    "*\\runonce.exe",
    "*\\runscripthelper.exe",
    "*\\schtasks.exe",
    "*\\scriptrunner.exe",
    "*\\stordiag.exe",
    "*\\ttdinject.exe",
    "*\\tttracer.exe",
    "*\\verclsid.exe",
    "*\\wab.exe",
    "*\\wmic.exe",
    "*\\xwizard.exe"
    )

NOT All_Traffic.dest_ip IN (
        "10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16",
        "100.64.0.0/10", "127.0.0.0/8", "169.254.0.0/16",
        "192.0.0.0/24", "192.0.0.0/29", "192.0.0.8/32",
        "192.0.0.9/32", "192.0.0.10/32", "192.0.0.170/32",
        "192.0.0.171/32", "192.0.2.0/24", "192.31.196.0/24",
        "192.52.193.0/24", "192.88.99.0/24", "224.0.0.0/4",
        "192.175.48.0/24", "198.18.0.0/15", "198.51.100.0/24",
        "203.0.113.0/24", "240.0.0.0/4"
    )

by All_Traffic.action All_Traffic.app All_Traffic.dest
   All_Traffic.dest_ip All_Traffic.dest_port
   All_Traffic.direction All_Traffic.dvc All_Traffic.protocol
   All_Traffic.protocol_version All_Traffic.src
   All_Traffic.src_ip All_Traffic.src_port
   All_Traffic.transport All_Traffic.user
   All_Traffic.vendor_product

| `drop_dm_object_name(All_Traffic)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `lolbas_rare_network_connection_filter`

Implementation guide

To successfully implement this detection you must ingest events into the Network Traffic data model that contain the source, destination, destination port, and communicating process name in the app field. Sysmon EventID 3 is a common source for this data when normalized into the Network Traffic data model.

Known false positives

  • Limited legitimate administrative automation and scripts may cause false positives. Any recurring use of these binaries for public network access should be reviewed, approved, and filtered with the analytic filter macro. Notepad.exe can now communicate with Microsoft's service "apsaiservices.microsoft.com" over port 443 to provide AI services. Apply filtering if this behavior is known in your environment. PowerShell, PowerShell ISE, PowerShell 7 (pwsh.exe), and cmd.exe are intentionally excluded from this analytic because they are too noisy.

Analyst notes

Known false positives: Limited legitimate administrative automation and scripts may cause false positives. Any recurring use of these binaries for public network access should be reviewed, approved, and filtered with the analytic filter macro. Notepad.exe can now communicate with Microsoft's service "apsaiservices.microsoft.com" over port 443 to provide AI services. Apply filtering if this behavior is known in your environment. PowerShell, PowerShell ISE, PowerShell 7 (pwsh.exe), and cmd.exe are intentionally excluded from this analytic because they are too noisy.

Raw source LOLBAS Rare Network Connection · SPL
Esc
Published by splunk/security_content ↗, licensed under Apache 2.0 ↗. Reproduced here unmodified. 
name: LOLBAS Rare Network Connection
id: d09b66cc-269b-4675-81b5-a3dabe4f5ac2
version: 1
creation_date: '2026-08-24'
modification_date: '2026-08-24'
author: Steven Dick, Nasreddine Bencherchali, Splunk
status: production
type: Anomaly
description: |
    The following analytic identifies public network connections initiated by Living Off the Land Binaries and Scripts (LOLBAS) that rarely require direct outbound network access.
    It leverages the Network Traffic data model and focuses on native Windows binaries where any public destination should be investigated and explicitly approved.
    This activity may indicate proxy execution, process injection, payload download, command-and-control, or other abuse of trusted binaries to evade security controls.
    Keep in mind that some of these binaries, such as Netsh.exe, Gpscript.exe, Wmic.exe, etc., will occasionally communicate with public network resources to perform their intended function.
    Exclude said processes from the detection if they are too noisy for your environment.
    Join this detection with the Process Execution events to provide context and avoid false positives.
data_source:
    - Sysmon EventID 3
search: |
    | tstats `security_content_summariesonly`
      count min(_time) as firstTime
            max(_time) as lastTime

    from datamodel=Network_Traffic.All_Traffic where

    All_Traffic.app IN (
        "*\\at.exe",
        "*\\atbroker.exe",
        "*\\certoc.exe",
        "*\\diskshadow.exe",
        "*\\dnscmd.exe",
        "*\\extexport.exe",
        "*\\forfiles.exe",
        "*\\gpscript.exe",
        "*\\infdefaultinstall.exe",
        "*\\installutil.exe",
        "*\\makecab.exe",
        "*\\mavinject.exe",
        "*\\microsoft.workflow.compiler.exe",
        "*\\msconfig.exe",
        "*\\netsh.exe",
        "*\\notepad.exe",
        "*\\odbcconf.exe",
        "*\\offlinescannershell.exe",
        "*\\pcalua.exe",
        "*\\pcwrun.exe",
        "*\\pnputil.exe",
        "*\\rasautou.exe",
        "*\\regasm.exe",
        "*\\register-cimprovider.exe",
        "*\\regsvcs.exe",
        "*\\regsvr32.exe",
        "*\\runonce.exe",
        "*\\runscripthelper.exe",
        "*\\schtasks.exe",
        "*\\scriptrunner.exe",
        "*\\stordiag.exe",
        "*\\ttdinject.exe",
        "*\\tttracer.exe",
        "*\\verclsid.exe",
        "*\\wab.exe",
        "*\\wmic.exe",
        "*\\xwizard.exe"
        )

    NOT All_Traffic.dest_ip IN (
            "10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16",
            "100.64.0.0/10", "127.0.0.0/8", "169.254.0.0/16",
            "192.0.0.0/24", "192.0.0.0/29", "192.0.0.8/32",
            "192.0.0.9/32", "192.0.0.10/32", "192.0.0.170/32",
            "192.0.0.171/32", "192.0.2.0/24", "192.31.196.0/24",
            "192.52.193.0/24", "192.88.99.0/24", "224.0.0.0/4",
            "192.175.48.0/24", "198.18.0.0/15", "198.51.100.0/24",
            "203.0.113.0/24", "240.0.0.0/4"
        )

    by All_Traffic.action All_Traffic.app All_Traffic.dest
       All_Traffic.dest_ip All_Traffic.dest_port
       All_Traffic.direction All_Traffic.dvc All_Traffic.protocol
       All_Traffic.protocol_version All_Traffic.src
       All_Traffic.src_ip All_Traffic.src_port
       All_Traffic.transport All_Traffic.user
       All_Traffic.vendor_product

    | `drop_dm_object_name(All_Traffic)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `lolbas_rare_network_connection_filter`
how_to_implement: |-
    To successfully implement this detection you must ingest events into the Network Traffic data model that contain the source, destination, destination port, and communicating process name in the app field. Sysmon EventID 3 is a common source for this data when normalized into the Network Traffic data model.
known_false_positives: |-
    Limited legitimate administrative automation and scripts may cause false positives.
    Any recurring use of these binaries for public network access should be reviewed, approved, and filtered with the analytic filter macro.
    Notepad.exe can now communicate with Microsoft's service "apsaiservices.microsoft.com" over port 443 to provide AI services. Apply filtering if this behavior is known in your environment.
    PowerShell, PowerShell ISE, PowerShell 7 (pwsh.exe), and cmd.exe are intentionally excluded from this analytic because they are too noisy.
references:
    - https://lolbas-project.github.io/#
    - https://www.sans.org/presentations/lolbin-detection-methods-seven-common-attacks-revealed/
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: dest
          type: system
          score: 20
          message: A rare public network connection from LOLBAS process [$app$] was observed on [$src$] to [$dest_ip$] over port [$dest_port$].
threat_objects:
    - field: app
      type: process_name
    - field: dest_ip
      type: ip_address
analytic_story:
    - Fake CAPTCHA Campaigns
    - Living Off The Land
    - Malicious Inno Setup Loader
    - Water Gamayun
    - APT37 Rustonotto and FadeStealer
    - GhostRedirector IIS Module and Rungan Backdoor
    - Hellcat Ransomware
    - NetSupport RMM Tool Abuse
asset_type: Endpoint
mitre_attack_id:
    - T1105
    - T1567
    - T1218
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: network
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1218/lolbas_with_network_traffic/lolbas_with_network_traffic.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

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