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splunk-security_content/detections/endpoint/execute_javascript_with_jscript_com_clsid.yml
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YAML

name: Execute Javascript With Jscript COM CLSID
id: dc64d064-d346-11eb-8588-acde48001122
version: 6
date: '2025-02-10'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects the execution of JavaScript using the
JScript.Encode CLSID (COM Object) by cscript.exe. It leverages data from Endpoint
Detection and Response (EDR) agents, focusing on process names, command-line executions,
and parent processes. This activity is significant as it is a known technique used
by ransomware, such as Reddot, to execute malicious scripts and potentially disable
AMSI (Antimalware Scan Interface). If confirmed malicious, this behavior could allow
attackers to execute arbitrary code, evade detection, and maintain persistence within
the environment.
data_source:
- Sysmon EventID 1
- Windows Event Log Security 4688
- CrowdStrike ProcessRollup2
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
as lastTime from datamodel=Endpoint.Processes where Processes.process_name = "cscript.exe"
Processes.process="*-e:{F414C262-6AC0-11CF-B6D1-00AA00BBBB58}*" by Processes.parent_process_name
Processes.process_name Processes.process Processes.parent_process Processes.process_id
Processes.dest Processes.user | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)` | `execute_javascript_with_jscript_com_clsid_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://app.any.run/tasks/c0f98850-af65-4352-9746-fbebadee4f05/
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 ("$user$",
"$dest$") 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: Suspicious process of cscript.exe with a parent process $parent_process_name$
where it tries to execute javascript using jscript.encode CLSID (COM OBJ), detected
on $dest$ by $user$
risk_objects:
- field: user
type: user
score: 56
- field: dest
type: system
score: 56
threat_objects:
- field: parent_process_name
type: parent_process_name
tags:
analytic_story:
- Ransomware
asset_type: Endpoint
mitre_attack_id:
- T1059.005
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/ransomware_ttp/data2/windows-sysmon.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: XmlWinEventLog