splunk-security_content/docs/_posts/2021-05-06-excessive_usage_of_net_app.md

title, excerpt, categories, last_modified_at, toc, toc_label, tags

title	excerpt	categories	last_modified_at	toc	toc_label	tags
Excessive Usage Of Net App	Account Access Removal	Endpoint	2021-05-06	true		Account Access Removal Impact Splunk Enterprise Splunk Enterprise Security Splunk Cloud Endpoint

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Description

This analytic identifies excessive usage of net.exe or net1.exe within a bucket of time (1 minute). This behavior was seen in a Monero incident where the adversary attempts to create many users, delete and disable users as part of its malicious behavior.

• Type: Anomaly
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel: Endpoint
• Last Updated: 2021-05-06
• Author: Teoderick Contreras, Splunk
• ID: 45e52536-ae42-11eb-b5c6-acde48001122

ATT&CK

ID	Technique	Tactic
T1531	Account Access Removal	Impact

Search

| tstats `security_content_summariesonly` values(Processes.process) as process values(Processes.process_id) as process_id count min(_time) as firstTime max(_time) as lastTime  from datamodel=Endpoint.Processes where `process_net` by Processes.process_name Processes.parent_process_name Processes.original_file_name Processes.dest Processes.user _time span=1m 
| where count >=10 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `excessive_usage_of_net_app_filter`

Associated Analytic Story

• XMRig
• Ransomware

How To Implement

To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Processes node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.

Required field

• _time
• Processes.dest
• Processes.user
• Processes.parent_process_name
• Processes.parent_process
• Processes.original_file_name
• Processes.process_name
• Processes.process
• Processes.process_id
• Processes.parent_process_path
• Processes.process_path
• Processes.parent_process_id

Kill Chain Phase

• Exploitation

Known False Positives

unknown. Filter as needed. Modify the time span as needed.

RBA

Risk Score	Impact	Confidence	Message
28.0	40	70	Excessive usage of net1.exe or net.exe within 1m, with command line process has been detected on dest by user

Reference

• https://thedfirreport.com/2020/04/20/sqlserver-or-the-miner-in-the-basement/

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

• https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/xmrig_miner/windows-sysmon.log

source | version: 2