Try in Splunk Security Cloud

Description

The search looks for files that contain the key word Ryuk under any folder in the C drive, which is consistent with Ryuk propagation.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2020-11-06
  • Author: Rod Soto, Jose Hernandez, Splunk
  • ID: 57d44d70-28d9-4ed1-acf5-1c80ae2bbce3

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1486 Data Encrypted for Impact Impact
Kill Chain Phase
  • Actions On Objectives
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem WHERE "Filesystem.file_path"=C:\\*Ryuk* BY "Filesystem.dest", "Filesystem.user", "Filesystem.file_path" 
| `drop_dm_object_name(Filesystem)` 
| `security_content_ctime(lastTime)` 
| `security_content_ctime(firstTime)` 
| `ryuk_test_files_detected_filter`

Macros

The SPL above uses the following Macros:

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

Required fields

List of fields required to use this analytic.

  • _time
  • Filesystem.file_path
  • Filesystem.dest
  • Filesystem.user

How To Implement

You must be ingesting data that records the filesystem activity from your hosts to populate the Endpoint Filesystem data-model object. If you are using Sysmon, you will need a Splunk Universal Forwarder on each endpoint from which you want to collect data.

Known False Positives

If there are files with this keywoord as file names it might trigger false possitives, please make use of our filters to tune out potential FPs.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
70.0 70 100 A creation of ryuk test file $file_path$ in host $dest$

:information_source: 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

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

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