Detection: Remote Desktop Network Bruteforce

REMOVED DETECTION

This detection has been removed from the Splunk Threat Research content library and is no longer maintained or supported.

Reason: Detection deprecated as it no longer effectively identifies the intended malicious activity

Removed in version: 5.4.0

Replacement: Windows Remote Desktop Network Bruteforce Attempt

If you have any questions or concerns, please reach out to us at research@splunk.com.

Updated Date: 2026-05-13 ID: a98727cc-286b-4ff2-b898-41df64695923 Author: Jose Hernandez, Bhavin Patel, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic has been deprecated in favor of "Windows Remote Desktop Network Bruteforce Attempt". The following analytic identifies potential Remote Desktop Protocol (RDP) brute force attacks by monitoring network traffic for RDP application activity. This query detects potential RDP brute force attacks by identifying source IPs that have made more than 10 successful connection attempts to the same RDP port on a host within a one-hour window. The results are presented in a table that includes the source and destination IPs, destination port, number of attempts, and the times of the first and last connection attempts, helping to prioritize IPs based on the intensity of activity.

Search

1
2| tstats `security_content_summariesonly` count, min(_time) as firstTime, max(_time) as lastTime from datamodel=Network_Traffic where (All_Traffic.app=rdp OR All_Traffic.dest_port=3389) AND All_Traffic.action=allowed by All_Traffic.src, All_Traffic.dest, All_Traffic.dest_port All_Traffic.user All_Traffic.vendor_product  
3| `drop_dm_object_name("All_Traffic")`  
4| eval duration=lastTime-firstTime  
5| where count > 10 AND duration < 3600  
6| `security_content_ctime(firstTime)`  
7| `security_content_ctime(lastTime)`  
8| `remote_desktop_network_bruteforce_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 3	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`

Macros Used

Name	Value
security_content_summariesonly	`summariesonly=`summariesonly_config `allow_old_summaries=`oldsummaries_config `fillnull_value=`fillnull_config``
remote_desktop_network_bruteforce_filter	``

remote_desktop_network_bruteforce_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
T1110.001	Password Guessing	Credential Access

Default Configuration

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

Setting	Value
Disabled	true
Cron Schedule	`N/A`
Earliest Time	`N/A`
Latest Time	`N/A`
Schedule Window	`N/A`
Creates Finding (Notable)	No
Creates Intermediate Finding (Risk Event)	No

TTP detections generate a Finding (Notable) and may generate Intermediate Findings (Risk Events) for associated entities.

Implementation

You must ensure that your network traffic data is populating the Network_Traffic data model. Adjust the count and duration thresholds as necessary to tune the sensitivity of your detection.

Known False Positives

RDP gateways may have unusually high amounts of traffic from all other hosts' RDP applications in the network.Any legitimate RDP traffic using wrong/expired credentials will be also detected as a false positive.

Associated Analytic Story

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	Not Applicable	N/A	N/A	N/A
Unit	Not Applicable	N/A	`N/A`	`N/A`
Integration	Not Applicable	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: 7