name: Linux DD File Overwrite
id: 9b6aae5e-8d85-11ec-b2ae-acde48001122
version: 1
date: '2022-02-14'
author: Teoderick Contreras, Splunk
type: TTP
datamodel:
- Endpoint
description: This analytic is to look for dd command to overwrite file. This technique
  was abused by adversaries or threat actor to destroy files or data on specific system
  or in a large number of host within network to interrupt host avilability, services
  and many more. This is also used to destroy data where it make the file irrecoverable
  by forensic techniques through overwriting files, data or local and remote drives.
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Endpoint.Processes where Processes.process_name = "dd"
  AND Processes.process = "*of=*" by Processes.dest Processes.user Processes.parent_process_name
  Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
  Processes.process_guid | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)` | `linux_dd_file_overwrite_filter`'
how_to_implement: To successfully implement this search, you need to be ingesting
  logs with the process name, parent process, and command-line executions from your
  endpoints. If you are using Sysmon, you can use the Add-on for Linux Sysmon from
  Splunkbase.
known_false_positives: Administrator or network operator can execute this command.
  Please update the filter macros to remove false positives.
references:
- https://gtfobins.github.io/gtfobins/dd/
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1485/T1485.md
tags:
  analytic_story:
  - Data Destruction
  - Industroyer2
  asset_type: endpoint
  cis20:
  - CIS 3
  - CIS 5
  - CIS 16
  confidence: 80
  context:
  - Source:Endpoint
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1485/linux_dd_file_overwrite/sysmon_linux.log
  impact: 80
  kill_chain_phases:
  - Exploitation
  message: A commandline $process$ executed on $dest$
  mitre_attack_id:
  - T1485
  nist:
  - DE.CM
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Processes.dest
  - Processes.user
  - Processes.parent_process_name
  - Processes.process_name
  - Processes.process
  - Processes.process_id
  - Processes.parent_process_id
  risk_score: 64
  security_domain: endpoint