Detect MSHTA Url in Command Line

SPLUNK detection rule by Michael Haag, Splunk · Apache-2.0

The following analytic detects the use of Microsoft HTML Application Host (mshta.exe) to make remote HTTP or HTTPS connections. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line arguments containing URLs. This activity is significant because adversaries often use mshta.exe to download and execute remote .hta files, bypassing security controls. If confirmed malicious, this behavior could allow attackers to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further network infiltration.

name: Detect MSHTA Url in Command Line
id: 9b3af1e6-5b68-11eb-ae93-0242ac130002
version: 21
creation_date: '2020-04-29'
modification_date: '2026-07-20'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic detects the use of Microsoft HTML Application Host (mshta.exe) to make remote HTTP or HTTPS connections. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line arguments containing URLs. This activity is significant because adversaries often use mshta.exe to download and execute remote .hta files, bypassing security controls. If confirmed malicious, this behavior could allow attackers to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further network infiltration.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
    - Cisco Network Visibility Module Flow Data
search: |-
    | tstats `security_content_summariesonly` count values(Processes.process) as process values(Processes.parent_process) as parent_process min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
      WHERE `process_mshta` (Processes.process="*http://*"
        OR
        Processes.process="*https://*")
      BY Processes.action Processes.dest Processes.original_file_name
         Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
         Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
         Processes.process Processes.process_exec Processes.process_guid
         Processes.process_hash Processes.process_id Processes.process_integrity_level
         Processes.process_name Processes.process_path Processes.user
         Processes.user_id Processes.vendor_product
    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `detect_mshta_url_in_command_line_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: It is possible legitimate applications may perform this behavior and will need to be filtered.
references:
    - https://github.com/redcanaryco/AtomicTestHarnesses
    - https://redcanary.com/blog/introducing-atomictestharnesses/
    - https://docs.microsoft.com/en-us/windows/win32/search/-search-3x-wds-extidx-prot-implementing
    - https://denwp.com/dissecting-lumma-malware/
    - https://www.mcafee.com/blogs/other-blogs/mcafee-labs/behind-the-captcha-a-clever-gateway-of-malware/
drilldown_searches:
    - name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - 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"
finding:
    title: An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting to access a remote destination to download an additional payload.
    entity:
        field: user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting to access a remote destination to download an additional payload.
threat_objects:
    - field: parent_process_name
      type: parent_process_name
    - field: process_name
      type: process_name
analytic_story:
    - APT37 Rustonotto and FadeStealer
    - Compromised Windows Host
    - Lumma Stealer
    - Living Off The Land
    - Suspicious MSHTA Activity
    - XWorm
    - Cisco Network Visibility Module Analytics
    - NetSupport RMM Tool Abuse
    - Starland RAT Campaign
asset_type: Endpoint
mitre_attack_id:
    - T1218.005
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test - Sysmon
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1218.005/atomic_red_team/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit
    - name: True Positive Test - Cisco NVM
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/cisco_network_visibility_module/cisco_nvm_flowdata/nvm_flowdata.log
          source: not_applicable
          sourcetype: cisco:nvm:flowdata:v2
      test_type: unit

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