Windows Shell or Script Execution From IIS Directory

SPLUNK detection rule by Raven Tait, Splunk · Apache-2.0

Detects Windows command tools such as cmd, PowerShell, or pwsh being executed from the IIS installation directory. This can be indicative of exploitation of software reliant on IIS such as Exchange.

name: Windows Shell or Script Execution From IIS Directory
id: f058f7f9-d5cf-4a79-a720-24e93e87c8bf
version: 2
creation_date: '2021-09-02'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: Anomaly
description: |-
    Detects Windows command tools such as cmd, PowerShell, or pwsh being executed from the IIS installation directory.
    This can be indicative of exploitation of software reliant on IIS such as Exchange.
data_source:
    - Sysmon EventID 1
    - CrowdStrike ProcessRollup2
search: |-
    | tstats `security_content_summariesonly`
      count min(_time) as firstTime
            max(_time) as lastTime

    from datamodel=Endpoint.Processes where

    Processes.process_current_directory="*:\\Windows\\System32\\inetsrv\\*"
    Processes.parent_process_name IN (
        "cmd.exe",
        "powershell.exe",
        "pwsh.exe"
    )

    by Processes.process Processes.vendor_product Processes.user_id Processes.process_hash
       Processes.parent_process_name Processes.parent_process_exec Processes.action
       Processes.dest Processes.process_current_directory Processes.process_path
       Processes.process_integrity_level Processes.original_file_name Processes.parent_process
       Processes.parent_process_path Processes.parent_process_guid Processes.parent_process_id
       Processes.process_guid Processes.process_id Processes.user Processes.process_name

    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_shell_or_script_execution_from_iis_directory_filter`
how_to_implement: The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives: Occasional administrative scripts or automated tasks might execute commands in the IIS directory. These instances are rare but should be verified before raising alerts.
drilldown_searches:
    - earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
      name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
    - name: View risk events for the last 7 days for - "$user$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") | 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: 50
          message: Potential Suspicious Commands in IIS Directory activity observed on $dest$ via $process$.
threat_objects:
    - field: parent_process_name
      type: parent_process_name
analytic_story:
    - ProxyShell
    - ProxyNotShell
asset_type: Endpoint
mitre_attack_id:
    - T1190
    - T1505.004
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/T1190/snapattack/snapattack.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

e67017f7-8c4b-4a74-844c-30dcb7c16c0e

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

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Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

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