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splunk-security_content/detections/endpoint/winword_spawning_powershell.yml
2023-03-23 10:35:34 +01:00

86 lines
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YAML

name: Winword Spawning PowerShell
id: b2c950b8-9be2-11eb-8658-acde48001122
version: 2
date: '2021-04-12'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following detection identifies Microsoft Word spawning PowerShell.
Typically, this is not common behavior and not default with winword.exe. Winword.exe
will generally be found in the following path `C:\Program Files\Microsoft Office\root\Office16`
(version will vary). PowerShell spawning from winword.exe is common for a spearphishing
attachment and is actively used. Albeit, the command executed will most likely be
encoded and captured via another detection. During triage, review parallel processes
and identify any files that may have been written.
data_source:
- Sysmon Event ID 1
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name="winword.exe"
`process_powershell` by Processes.dest Processes.user Processes.parent_process Processes.process_name
Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id
| `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)`
| `winword_spawning_powershell_filter`'
how_to_implement: To successfully implement this search you need to be ingesting information
on process that include the name of the process responsible for the changes from
your endpoints into the `Endpoint` datamodel in the `Processes` node. In addition,
confirm the latest CIM App 4.20 or higher is installed and the latest TA for the
endpoint product.
known_false_positives: False positives should be limited, but if any are present,
filter as needed.
references:
- https://redcanary.com/threat-detection-report/techniques/powershell/
- https://attack.mitre.org/techniques/T1566/001/
- https://app.any.run/tasks/b79fa381-f35c-4b3e-8d02-507e7ee7342f/
- https://app.any.run/tasks/181ac90b-0898-4631-8701-b778a30610ad/
tags:
analytic_story:
- Spearphishing Attachments
- DarkCrystal RAT
- CVE-2023-21716 Word RTF Heap Corruption
asset_type: Endpoint
confidence: 100
impact: 70
message: '$parent_process_name$ on $dest$ by $user$ launched the following powershell
process: $process_name$ which is very common in spearphishing attacks'
mitre_attack_id:
- T1566
- T1566.001
observable:
- name: dest
type: Endpoint
role:
- Victim
- name: user
type: User
role:
- Victim
- name: process_name
type: Process
role:
- Target
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
required_fields:
- _time
- Processes.dest
- Processes.user
- Processes.parent_process_name
- Processes.parent_process
- Processes.original_file_name
- Processes.process_name
- Processes.process
- Processes.process_id
- Processes.parent_process_path
- Processes.process_path
- Processes.parent_process_id
risk_score: 70
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1566.001/macro/windows-sysmon.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: xmlwineventlog