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splunk-security_content/detections/endpoint/jscript_execution_using_cscript_app.yml

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YAML

name: Jscript Execution Using Cscript App
id: 002f1e24-146e-11ec-a470-acde48001122
version: 8
date: '2025-05-02'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects the execution of JScript using the cscript.exe
process. It leverages data from Endpoint Detection and Response (EDR) agents, focusing
on process and command-line telemetry. This behavior is significant because JScript
files are typically executed by wscript.exe, making cscript.exe execution unusual
and potentially indicative of malicious activity, such as the FIN7 group's tactics.
If confirmed malicious, this activity could allow attackers to execute arbitrary
scripts, leading to code execution, data exfiltration, or further system compromise.
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.parent_process_name
= "cscript.exe" AND Processes.parent_process = "*//e:jscript*") OR (Processes.process_name
= "cscript.exe" AND Processes.process = "*//e:jscript*") 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)`
| `jscript_execution_using_cscript_app_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: unknown
references:
- https://www.mandiant.com/resources/fin7-pursuing-an-enigmatic-and-evasive-global-criminal-operation
- https://attack.mitre.org/groups/G0046/
drilldown_searches:
- name: View the detection results for - "$dest$" and "$user$"
search: '%original_detection_search% | search dest = "$dest$" user = "$user$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$dest$" and "$user$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$",
"$user$") starthoursago=168 | 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: $info_min_time$
latest_offset: $info_max_time$
rba:
message: Process name $process_name$ with commandline $process$ to execute jscript
on $dest$
risk_objects:
- field: dest
type: system
score: 49
- field: user
type: user
score: 49
threat_objects: []
tags:
analytic_story:
- FIN7
- Remcos
asset_type: Endpoint
mitre_attack_id:
- T1059.007
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/fin7/fin7_macro_js_1/sysmon.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: XmlWinEventLog