windows_abused_web_services.yml

name: Windows Abused Web Services
id: 01f0aef4-8591-4daa-a53d-0ed49823b681
version: 1
date: '2023-09-20'
author: Teoderick Contreras, Splunk
status: production
type: TTP
data_source:
- Sysmon EventID 22
description: The following analytic detects a suspicious process making a DNS query via known,
  abused text-paste web services, VoIP, internet via secure tunneling,instant messaging, and digital distribution
  platforms used to download external files. This technique is abused by adversaries,
  malware actors, and red teams to download a malicious file on the target host. This
  is a good TTP indicator for possible initial access techniques. A user will experience
  false positives if the following instant messaging is allowed or common applications
  like telegram or discord are allowed in the corporate network.
search: '`sysmon` EventCode=22 QueryName IN ("*pastebin*",""*textbin*"", "*ngrok.io*", "*discord*", "*duckdns.org*", "*pasteio.com*") 
  | stats count min(_time) as firstTime max(_time) as lastTime by Image QueryName QueryStatus process_name QueryResults Computer
  | rename Computer as dest 
  | `security_content_ctime(firstTime)` 
  | `security_content_ctime(lastTime)` 
  | `windows_abused_web_services_filter`'
how_to_implement: This detection relies on sysmon logs with the Event ID 22, DNS Query.
  We suggest you run this detection at least once a day over the last 14 days.
known_false_positives: Noise and false positive can be seen if the following instant
  messaging is allowed to use within corporate network. In this case, a filter is
  needed.
references:
- https://malpedia.caad.fkie.fraunhofer.de/details/win.njrat
tags:
  analytic_story:
  - NjRAT
  asset_type: Endpoint
  confidence: 60
  impact: 60
  message: a network connection on known abused web services from $dest$
  mitre_attack_id:
  - T1102
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: process_name
    type: Process
    role:
    - Attacker
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  risk_score: 36
  required_fields:
  - _time
  - Image
  - QueryName
  - QueryStatus
  - process_name
  - QueryResults
  - Computer
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1102/njrat_ngrok_connection/ngrok.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog