splunk-security_content/docs/_posts/2021-03-16-high_process_termination_frequency.md

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

title	excerpt	categories	last_modified_at	toc	toc_label	tags
High Process Termination Frequency	Data Encrypted for Impact	Endpoint	2021-03-16	true		Data Encrypted for Impact Impact Splunk Enterprise Splunk Enterprise Security Splunk Cloud Endpoint

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Description

This analytics are designed to indentify a high frequency of process termination on a machine which is a common behavior of ransomware malware before encrypting files. This technique is designed to avoid an exception error while accessing (docs, images, database and etc..) in the infected machine for encryption.

• Type: Anomaly
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel: Endpoint
• Last Updated: 2021-03-16
• Author: Teoderick Contreras
• ID: 17cd75b2-8666-11eb-9ab4-acde48001122

Annotations

ATT&CK

ID	Technique	Tactic
T1486	Data Encrypted for Impact	Impact

Kill Chain Phase

• Exploitation

NIST

CIS20

CVE

Search

`sysmon` EventCode=5 
|bin _time span=3s 
|stats values(Image) as proc_terminated min(_time) as firstTime max(_time) as lastTime  count by Computer EventCode ProcessID 
| where count >= 15 
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)` 
| `high_process_termination_frequency_filter`

Macros

The SPL above uses the following Macros:

• security_content_ctime
• sysmon

ℹ️ high_process_termination_frequency_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required field

• EventCode
• Image
• Computer
• _time
• ProcessID

How To Implement

To successfully implement this search, you need to be ingesting logs with the Image (process full path of terminated process) from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.

Known False Positives

admin or user tool that can terminate multiple process.

Associated Analytic story

• Clop Ransomware

RBA

Risk Score	Impact	Confidence	Message
72.0	90	80	High frequency process termination (more than 15 processes within 3s) detected on host Computer

ℹ️ The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

• https://www.mandiant.com/resources/fin11-email-campaigns-precursor-for-ransomware-data-theft
• https://blog.virustotal.com/2020/11/keep-your-friends-close-keep-ransomware.html

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/clop/clop_a/windows-sysmon.log

source | version: 1