Detection rules › Splunk

Recon AVProduct Through Pwh or WMI

Status
production
Severity
medium
Group by
Guid, Name, Opcode, Path, ScriptBlockId, ScriptBlockText, dest, process_id, signature, signature_id, user_id, vendor_product
Author
Teoderick Contreras, Splunk
Source
github.com/splunk/security_content

The following analytic detects suspicious PowerShell script execution via EventCode 4104, specifically targeting checks for installed anti-virus products using WMI or PowerShell commands. This detection leverages PowerShell Script Block Logging to identify scripts containing keywords like "SELECT," "WMIC," "AntiVirusProduct," or "AntiSpywareProduct." This activity is significant as it is commonly used by malware and APT actors to map running security applications or services, potentially aiding in evasion techniques. If confirmed malicious, this could allow attackers to disable or bypass security measures, leading to further compromise of the endpoint.

MITRE ATT&CK coverage

TacticTechniques
ReconnaissanceT1592 Gather Victim Host Information

Event coverage

Rule body splunk

name: Recon AVProduct Through Pwh or WMI
id: 28077620-c9f6-11eb-8785-acde48001122
version: 15
creation_date: '2021-06-14'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects suspicious PowerShell script execution via EventCode 4104, specifically targeting checks for installed anti-virus products using WMI or PowerShell commands. This detection leverages PowerShell Script Block Logging to identify scripts containing keywords like "SELECT," "WMIC," "AntiVirusProduct," or "AntiSpywareProduct." This activity is significant as it is commonly used by malware and APT actors to map running security applications or services, potentially aiding in evasion techniques. If confirmed malicious, this could allow attackers to disable or bypass security measures, leading to further compromise of the endpoint.
data_source:
    - Powershell Script Block Logging 4104
search: |-
    `powershell` EventCode=4104 (ScriptBlockText = "*SELECT*" OR ScriptBlockText = "*WMIC*") AND (ScriptBlockText = "*AntiVirusProduct*" OR ScriptBlockText = "*AntiSpywareProduct*")
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY dest signature signature_id
           user_id vendor_product EventID
           Guid Opcode Name
           Path ProcessID ScriptBlockId
           ScriptBlockText
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `recon_avproduct_through_pwh_or_wmi_filter`
how_to_implement: To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://help.splunk.com/en/security-offerings/splunk-user-behavior-analytics/get-data-in/5.4.1/add-other-data-to-splunk-uba/configure-powershell-logging-to-see-powershell-anomalies-in-splunk-uba.
known_false_positives: network administrator may used this command for checking purposes
references:
    - https://news.sophos.com/en-us/2020/05/12/maze-ransomware-1-year-counting/
    - https://help.splunk.com/en/security-offerings/splunk-user-behavior-analytics/get-data-in/5.4.1/add-other-data-to-splunk-uba/configure-powershell-logging-to-see-powershell-anomalies-in-splunk-uba.
    - https://blog.palantir.com/tampering-with-windows-event-tracing-background-offense-and-defense-4be7ac62ac63
    - https://static1.squarespace.com/static/552092d5e4b0661088167e5c/t/59c1814829f18782e24f1fe2/1505853768977/Windows+PowerShell+Logging+Cheat+Sheet+ver+Sept+2017+v2.1.pdf
    - https://www.crowdstrike.com/blog/investigating-powershell-command-and-script-logging/
    - https://www.splunk.com/en_us/blog/security/hunting-for-malicious-powershell-using-script-block-logging.html
drilldown_searches:
    - name: View the detection results for - "$dest$" and "$user_id$"
      search: '%original_detection_search% | search  dest = "$dest$" user_id = "$user_id$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$" and "$user_id$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user_id$") | 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: A suspicious powershell script contains AV recon command on host $dest$
    entity:
        field: user_id
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: A suspicious powershell script contains AV recon command on host $dest$
analytic_story:
    - XWorm
    - Ransomware
    - Hermetic Wiper
    - Prestige Ransomware
    - Quasar RAT
    - Malicious PowerShell
    - Data Destruction
    - MoonPeak
    - Qakbot
    - Windows Post-Exploitation
asset_type: Endpoint
mitre_attack_id:
    - T1592
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/t1592/pwh_av_recon/windows-powershell-xml.log
          source: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

Stages and Predicates

Stage 1: search

`powershell` EventCode=4104 (ScriptBlockText = "*SELECT*" OR ScriptBlockText = "*WMIC*") AND (ScriptBlockText = "*AntiVirusProduct*" OR ScriptBlockText = "*AntiSpywareProduct*")

Stage 2: fillnull

| fillnull

Stage 3: stats

| stats count min(_time) as firstTime max(_time) as lastTime
    BY dest signature signature_id
       user_id vendor_product EventID
       Guid Opcode Name
       Path ProcessID ScriptBlockId
       ScriptBlockText

Stage 4: search

| `security_content_ctime(firstTime)`

Stage 5: search

| `security_content_ctime(lastTime)`

Stage 6: search

| `recon_avproduct_through_pwh_or_wmi_filter`

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.

FieldKindValues
EventCodeeq
  • 4104 corpus 268 (splunk 268)
ScriptBlockTexteq
  • "*AntiSpywareProduct*"
  • "*AntiVirusProduct*"
  • "*SELECT*" corpus 3 (splunk 3)
  • "*WMIC*"