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The following analytic identifies the presence of files containing the keyword "Ryuk" in any folder on the C drive, indicative of Ryuk ransomware activity. It leverages the Endpoint Filesystem data model to detect file paths matching this pattern. This activity is significant as Ryuk ransomware is known for its destructive impact, encrypting critical files and demanding ransom. If confirmed malicious, this could lead to significant data loss, operational disruption, and financial damage due to ransom payments and recovery efforts. Immediate investigation and response are crucial to mitigate potential damage.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2024-05-20
  • Author: Rod Soto, Jose Hernandez, Splunk
  • ID: 57d44d70-28d9-4ed1-acf5-1c80ae2bbce3




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


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


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.


Test Dataset

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

source | version: 2