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Description

The following analytic detects the writing of files from known remote access software to disk within the environment. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on file path, file name, and user information. This activity is significant as adversaries often use remote access tools like AnyDesk, GoToMyPC, LogMeIn, and TeamViewer to maintain unauthorized access. If confirmed malicious, this could allow attackers to persist in the environment, potentially leading to data exfiltration, further compromise, or complete control over affected systems.

  • Type: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2024-05-13
  • Author: Steven Dick
  • ID: 3bf5541a-6a45-4fdc-b01d-59b899fff961

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1219 Remote Access Software Command And Control
Kill Chain Phase
  • Command and Control
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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| tstats `security_content_summariesonly` count, min(_time) as firstTime, max(_time) as lastTime, values(Filesystem.file_path) as file_path from datamodel=Endpoint.Filesystem by Filesystem.dest, Filesystem.user, Filesystem.file_name 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `drop_dm_object_name(Filesystem)` 
| lookup remote_access_software remote_utility AS file_name OUTPUT isutility, description as signature, comment_reference as desc, category 
| search isutility = TRUE 
| `detect_remote_access_software_usage_file_filter`

Macros

The SPL above uses the following Macros:

:information_source: detect_remote_access_software_usage_file_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
  • Filesystem.dest
  • Filesystem.user
  • Filesystem.file_name

How To Implement

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the file path, file name, and the user that created the file. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Filesystem node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

Known or approved applications used by the organization or usage of built-in functions.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
25.0 50 50 A file for known a remote access software [$file_name$] was created on $dest$ by $user$.

:information_source: 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

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: 2