usn_journal_deletion.yml

name: USN Journal Deletion
id: b6e0ff70-b122-4227-9368-4cf322ab43c3
version: 2
date: '2018-12-03'
author: David Dorsey, Splunk
status: production
type: TTP
description: The fsutil.exe application is a legitimate Windows utility used to perform
  tasks related to the file allocation table (FAT) and NTFS file systems. The update
  sequence number (USN) change journal provides a log of all changes made to the files
  on the disk. This search looks for fsutil.exe deleting the USN journal.
data_source:
- Sysmon EventID 1
search: '| tstats `security_content_summariesonly` count values(Processes.process)
  as process values(Processes.parent_process) as parent_process min(_time) as firstTime
  max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name=fsutil.exe
  by Processes.user Processes.process_name Processes.parent_process_name Processes.dest  |
  `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)`
  | search process="*deletejournal*" AND process="*usn*" | `usn_journal_deletion_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: None identified
references: []
tags:
  analytic_story:
  - Windows Log Manipulation
  - Ransomware
  asset_type: Endpoint
  confidence: 90
  impact: 50
  message: Possible USN journal deletion on $dest$
  mitre_attack_id:
  - T1070
  observable:
  - name: dest
    type: Endpoint
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Processes.process
  - Processes.parent_process
  - Processes.process_name
  - Processes.user
  - Processes.parent_process_name
  - Processes.dest
  risk_score: 45
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1070/atomic_red_team/windows-sysmon.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog