Detection: Windows RDP Connection Successful

Updated Date: 2024-05-20 ID: ceaed840-56b3-4a70-b8e1-d762b1c5c08c Author: Michael Haag, Splunk Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic detects successful Remote Desktop Protocol (RDP) connections by monitoring EventCode 1149 from the Windows TerminalServices RemoteConnectionManager Operational log. This detection is significant as successful RDP connections can indicate remote access to a system, which may be leveraged by attackers to control or exfiltrate data. If confirmed malicious, this activity could lead to unauthorized access, data theft, or further lateral movement within the network. Monitoring successful RDP connections is crucial for identifying potential security breaches and mitigating risks promptly.

Search

1`remoteconnectionmanager` EventCode=1149 
2| stats count min(_time) as firstTime max(_time) as lastTime by Computer, user_id 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| rename Computer as dest 
6| `windows_rdp_connection_successful_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
Windows Event Log RemoteConnectionManager 1149	Windows	`'wineventlog'`	`'WinEventLog:Microsoft-Windows-TerminalServices-RemoteConnectionManager/Operational'`	N/A

Macros Used

Name	Value
remoteconnectionmanager	`source="WinEventLog:Microsoft-Windows-TerminalServices-RemoteConnectionManager/Operational"`
windows_rdp_connection_successful_filter	`search *`

windows_rdp_connection_successful_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
T1563.002	RDP Hijacking	Lateral Movement

KillChainPhase.EXPLOITAITON

NistCategory.DE_AE

Cis18Value.CIS_10

Axiom

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 Risk Event	False

This configuration file applies to all detections of type hunting.

Implementation

The following analyic requires the WIndows TerminalServices RemoteConnectionManager Operational log to be enabled and ingested into Splunk. For the inputs, review https://gist.github.com/MHaggis/138c6bf563bacbda4a2524f089773706.

Known False Positives

False positives will be present, filter as needed or restrict to critical assets on the perimeter.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
A successful RDP connection on $dest$ occurred.	25	50	50

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`WinEventLog:Microsoft-Windows-TerminalServices-RemoteConnectionManager/Operational`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`WinEventLog:Microsoft-Windows-TerminalServices-RemoteConnectionManager/Operational`	`XmlWinEventLog`

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: 3