Detect Remote Access Software Usage DNS
Description
The following analytic detects when a known remote access software domains are contacted from within the environment. Adversaries use these utilities to retain remote access capabilities to the environment. Utilities in the lookup include AnyDesk, GoToMyPC, LogMeIn, TeamViewer and much more. Review the lookup for the entire list and add any others.
- Type: Anomaly
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Network_Resolution
- Last Updated: 2024-02-22
- Author: Steven Dick
- ID: a16b797d-e309-41bd-8ba0-5067dae2e4be
Annotations
Kill Chain Phase
- Command and Control
NIST
- DE.AE
CIS20
- CIS 10
CVE
Search
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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime values(DNS.answer) as answer from datamodel=Network_Resolution by DNS.src DNS.query
| `drop_dm_object_name("DNS")`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| lookup remote_access_software remote_domain AS query OUTPUT isutility, description as signature, comment_reference as desc, category
| eval dest = query
| search isutility = True
| `detect_remote_access_software_usage_dns_filter`
Macros
The SPL above uses the following Macros:
detect_remote_access_software_usage_dns_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Lookups
The SPL above uses the following Lookups:
Required fields
List of fields required to use this analytic.
- _time
- DNS.src
- DNS.query
- DNS.answer
How To Implement
To implement this search, you must ingest logs that contain the DNS query and the source of the query. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the DNS logs. The logs must also be mapped to the Network_Resolution
data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
Known False Positives
It is possible that legitimate remote access software is used within the environment. Ensure that the lookup is reviewed and updated with any additional remote access software that is used within the environment.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
25.0 | 50 | 50 | A domain for a known remote access software $query$ was contacted by $src$. |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
- https://attack.mitre.org/techniques/T1219/
- https://thedfirreport.com/2022/08/08/bumblebee-roasts-its-way-to-domain-admin/
- https://thedfirreport.com/2022/11/28/emotet-strikes-again-lnk-file-leads-to-domain-wide-ransomware/
Test Dataset
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 | version: 1