Detection: Detect web traffic to dynamic domain providers

DEPRECATED DETECTION

This detection has been marked as deprecated by the Splunk Threat Research team. This means that it will no longer be maintained or supported. If you have any questions or concerns, please reach out to us at research@splunk.com.

Updated Date: 2024-11-14 ID: 134da869-e264-4a8f-8d7e-fcd01c18f301 Author: Bhavin Patel, Splunk Type: TTP Product: Splunk Enterprise Security

Description

This search looks for web connections to dynamic DNS providers.

1
2| tstats `security_content_summariesonly` count values(Web.url) as url min(_time) as firstTime from datamodel=Web where Web.status=200 by Web.src Web.dest Web.status 
3| `drop_dm_object_name("Web")` 
4| `security_content_ctime(firstTime)` 
5| `dynamic_dns_web_traffic` 
6| `detect_web_traffic_to_dynamic_domain_providers_filter`

Data Source

No data sources specified for this detection.

Macros Used

Name Value
dynamic_dns_web_traffic `lookup update=true dynamic_dns_providers_default dynamic_dns_domains as url OUTPUTNEW isDynDNS_default
detect_web_traffic_to_dynamic_domain_providers_filter search *
detect_web_traffic_to_dynamic_domain_providers_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1071.001 Web Protocols Command And Control
Command and Control
DE.CM
CIS 13

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

This search requires you to be ingesting web-traffic logs. You can obtain these logs from indexing data from a web proxy or by using a network-traffic-analysis tool, such as Bro or Splunk Stream. The web data model must contain the URL being requested, the IP address of the host initiating the request, and the destination IP. This search also leverages a lookup file, dynamic_dns_providers_default.csv, which contains a non-exhaustive list of dynamic DNS providers. Consider periodically updating this local lookup file with new domains. This search produces fields (isDynDNS) that are not yet supported by ES Incident Review and therefore cannot be viewed when a finding event is raised. These fields contribute additional context to the finding. To see the additional metadata, add the following fields, if not already present, to Incident Review - Event Attributes (Configure > Incident Management > Incident Review Settings > Add New Entry):

  • Label: IsDynamicDNS, Field: isDynDNS Deprecated because duplicate.

Known False Positives

It is possible that list of dynamic DNS providers is outdated and/or that the URL being requested is legitimate.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

Web traffic to Dynamic DNS Provider detected

Risk Object Risk Object Type Risk Score Threat Objects
dest system 25 No Threat Objects

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation Not Applicable N/A N/A N/A
Unit ❌ Failing N/A N/A N/A
Integration ❌ Failing N/A N/A N/A

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 5