> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/analytics-alerts/alerts-by-name/an-uncommon-rdp-session-was-established.md).
# An uncommon RDP session was established
### Synopsis
| Field | Value |
| -------------------- | ---------------------------------------------------- |
| Activation Period | 14 Days |
| Training Period | 30 Days |
| Test Period | N/A (single event) |
| Deduplication Period | 1 Day |
| Required Data | XDR Agent |
| Detector Tags | Enhanced RDP Analytics |
| ATT\&CK Tactic | Lateral Movement (TA0008) |
| ATT\&CK Technique | Remote Services: Remote Desktop Protocol (T1021.001) |
| Severity | Informational |
### Description
An RDP session was established with uncommon parameters.
### Attacker's Goals
Adversaries may use RDP for initial access or lateral movement within a network.
### Investigative actions
* Investigate the source and destination of the RDP communication.
* Check if this communication is legitimate and expected.
* Analyze the user and process that initiated the RDP connection.
### Variations
An uncommon RDP session was established by an RMM actor
**Synopsis**
| Field | Value |
| ----------------- | ---------------------------------------------------- |
| ATT\&CK Tactic | Lateral Movement (TA0008) |
| ATT\&CK Technique | Remote Services: Remote Desktop Protocol (T1021.001) |
| Severity | Low |
**Description**
An RDP session was established with uncommon parameters. The session was initiated under a Remote Monitoring & Management CGO.
**Attacker's Goals**
Adversaries may use RDP for initial access or lateral movement within a network.
**Investigative actions**
* Investigate the source and destination of the RDP communication.
* Check if this communication is legitimate and expected.
* Analyze the user and process that initiated the RDP connection.
An uncommon RDP session was established from a Suspicious Autonomous System (AS)
**Synopsis**
| Field | Value |
| ----------------- | ---------------------------------------------------- |
| ATT\&CK Tactic | Lateral Movement (TA0008) |
| ATT\&CK Technique | Remote Services: Remote Desktop Protocol (T1021.001) |
| Severity | Medium |
**Description**
An RDP session was established with uncommon parameters.
**Attacker's Goals**
Adversaries may use RDP for initial access or lateral movement within a network.
**Investigative actions**
* Investigate the source and destination of the RDP communication.
* Check if this communication is legitimate and expected.
* Analyze the user and process that initiated the RDP connection.
An uncommon RDP session was established originating from a chained RDP session which is also from a rare subnet
**Synopsis**
| Field | Value |
| ----------------- | ---------------------------------------------------- |
| ATT\&CK Tactic | Lateral Movement (TA0008) |
| ATT\&CK Technique | Remote Services: Remote Desktop Protocol (T1021.001) |
| Severity | Low |
**Description**
An RDP session was established with uncommon parameters. The connection appears to originate from an endpoint that itself received an RDP connection, suggesting a chained session.
**Attacker's Goals**
Adversaries may use RDP for initial access or lateral movement within a network.
**Investigative actions**
* Investigate the source and destination of the RDP communication.
* Check if this communication is legitimate and expected.
* Analyze the user and process that initiated the RDP connection.
An uncommon RDP session was established between subnets with no prior communication
**Synopsis**
| Field | Value |
| ----------------- | ---------------------------------------------------- |
| ATT\&CK Tactic | Lateral Movement (TA0008) |
| ATT\&CK Technique | Remote Services: Remote Desktop Protocol (T1021.001) |
| Severity | Low |
**Description**
An RDP session was established with uncommon parameters. The source and destination subnets have not been observed communicating with each other previously.
**Attacker's Goals**
Adversaries may use RDP for initial access or lateral movement within a network.
**Investigative actions**
* Investigate the source and destination of the RDP communication.
* Check if this communication is legitimate and expected.
* Analyze the user and process that initiated the RDP connection.
An uncommon RDP session was established involving subnets with no prior RDP history
**Synopsis**
| Field | Value |
| ----------------- | ---------------------------------------------------- |
| ATT\&CK Tactic | Lateral Movement (TA0008) |
| ATT\&CK Technique | Remote Services: Remote Desktop Protocol (T1021.001) |
| Severity | Low |
**Description**
An RDP session was established with uncommon parameters. Neither the source nor the destination subnet has been observed participating in RDP sessions previously.
**Attacker's Goals**
Adversaries may use RDP for initial access or lateral movement within a network.
**Investigative actions**
* Investigate the source and destination of the RDP communication.
* Check if this communication is legitimate and expected.
* Analyze the user and process that initiated the RDP connection.
An uncommon RDP session was established involving a destination subnet which rarely receives incoming RDP sessions
**Synopsis**
| Field | Value |
| ----------------- | ---------------------------------------------------- |
| ATT\&CK Tactic | Lateral Movement (TA0008) |
| ATT\&CK Technique | Remote Services: Remote Desktop Protocol (T1021.001) |
| Severity | Low |
**Description**
An RDP session was established with uncommon parameters. The destination subnet is rarely involved in RDP activity.
**Attacker's Goals**
Adversaries may use RDP for initial access or lateral movement within a network.
**Investigative actions**
* Investigate the source and destination of the RDP communication.
* Check if this communication is legitimate and expected.
* Analyze the user and process that initiated the RDP connection.
---
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