mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
tccontre
96 lines
3.4 KiB
YAML
96 lines
3.4 KiB
YAML
name: Any Powershell DownloadFile
|
|
id: 1a93b7ea-7af7-11eb-adb5-acde48001122
|
|
version: 3
|
|
date: '2022-04-07'
|
|
author: Michael Haag, Splunk
|
|
type: TTP
|
|
datamodel:
|
|
- Endpoint
|
|
description: The following analytic identifies the use of PowerShell downloading a
|
|
file using `DownloadFile` method. This particular method is utilized in many different
|
|
PowerShell frameworks to download files and output to disk. Identify the source
|
|
(IP/domain) and destination file and triage appropriately. If AMSI logging or PowerShell
|
|
transaction logs are available, review for further details of the implant.
|
|
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
|
|
as lastTime from datamodel=Endpoint.Processes where `process_powershell` Processes.process=*DownloadFile*
|
|
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)`|
|
|
`any_powershell_downloadfile_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 may be present and filtering will need to occur
|
|
by parent process or command line argument. It may be required to modify this query
|
|
to an EDR product for more granular coverage.
|
|
references:
|
|
- https://docs.microsoft.com/en-us/dotnet/api/system.net.webclient.downloadfile?view=net-5.0
|
|
- https://blog.malwarebytes.com/malwarebytes-news/2021/02/lazyscripter-from-empire-to-double-rat/
|
|
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1059.001/T1059.001.md
|
|
tags:
|
|
analytic_story:
|
|
- Hermetic Wiper
|
|
- Malicious PowerShell
|
|
- Ingress Tool Transfer
|
|
- Log4Shell CVE-2021-44228
|
|
- DarkCrystal RAT
|
|
confidence: 70
|
|
context:
|
|
- Source:Endpoint
|
|
- Stage:Execution
|
|
cve:
|
|
- CVE-2021-44228
|
|
dataset:
|
|
- https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1059.001/atomic_red_team/windows-sysmon.log
|
|
impact: 80
|
|
kill_chain_phases:
|
|
- Exploitation
|
|
message: An instance of $parent_process_name$ spawning $process_name$ was identified
|
|
on endpoint $dest$ by user $user$. This behavior identifies the use of DownloadFile
|
|
within PowerShell.
|
|
mitre_attack_id:
|
|
- T1059
|
|
- T1059.001
|
|
- T1105
|
|
observable:
|
|
- name: user
|
|
type: User
|
|
role:
|
|
- Victim
|
|
- name: dest
|
|
type: Hostname
|
|
role:
|
|
- Victim
|
|
- name: parent_process_name
|
|
type: Process
|
|
role:
|
|
- Parent Process
|
|
- name: process_name
|
|
type: Process
|
|
role:
|
|
- Child Process
|
|
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: 56
|
|
security_domain: endpoint
|
|
supported_tas:
|
|
- Splunk_TA_microsoft_sysmon
|
|
asset_type: Endpoint
|