malicious_powershell_process___encoded_command.yml

name: Malicious PowerShell Process - Encoded Command
id: c4db14d9-7909-48b4-a054-aa14d89dbb19
version: 4
date: '2020-07-21'
author: David Dorsey, Splunk
type: batch
datamodel:
- Endpoint
description: This search looks for PowerShell processes that have encoded the script
  within the command-line. Malware has been seen using this parameter, as it obfuscates
  the code and makes it relatively easy to pass a script on the command-line.
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Endpoint.Processes where Processes.process_name = powershell.exe
  (Processes.process=*-EncodedCommand* OR Processes.process=*-enc*) by Processes.user
  Processes.process_name Processes.process Processes.parent_process_name Processes.dest
  Processes.process_id | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`|
  `security_content_ctime(lastTime)` | `malicious_powershell_process___encoded_command_filter`'
how_to_implement: You must be ingesting data that records process activity from your
  hosts to populate the Endpoint data model in the Processes node. You must also be
  ingesting logs with both the process name and command line from your endpoints.
  The command-line arguments are mapped to the "process" field in the Endpoint data
  model.
known_false_positives: System administrators may use this option, but it's not common.
references: []
tags:
  analytic_story:
  - Malicious PowerShell
  - NOBELIUM Group
  asset_type: Endpoint
  automated_detection_testing: passed
  cis20:
  - CIS 3
  - CIS 7
  - CIS 8
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1027/atomic_red_team/windows-sysmon.log
  kill_chain_phases:
  - Command and Control
  - Actions on Objectives
  mitre_attack_id:
  - T1027
  nist:
  - PR.PT
  - DE.CM
  - PR.IP
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Processes.process_name
  - Processes.process
  - Processes.user
  - Processes.parent_process_name
  - Processes.dest
  - Processes.process_id
  security_domain: endpoint