> 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/uncommon-network-tunnel-creation.md).

# Uncommon network tunnel creation

### Synopsis

| Field                | Value                        |
| -------------------- | ---------------------------- |
| Activation Period    | 14 Days                      |
| Training Period      | 30 Days                      |
| Test Period          | N/A (single event)           |
| Deduplication Period | 12 Hours                     |
| Required Data        | Palo Alto Networks Url Logs  |
| ATT\&CK Tactic       | Command and Control (TA0011) |
| ATT\&CK Technique    | Protocol Tunneling (T1572)   |
| Severity             | Informational                |

### Description

An uncommon network tunnel was established.

### Attacker's Goals

Attackers may use SSH or any similar utility to create a network tunnel to allow an attacker to covertly connect to an internal host.

### Investigative actions

* Review the external IP/domain using known intelligence tools.
* Investigate the causality of the process and its user ID to find uncommon behaviors.
* Search for processes or files that were created by this SSH instance.

### Variations

<details>

<summary>Uncommon network tunnel creation</summary>

**Synopsis**

| Field             | Value                        |
| ----------------- | ---------------------------- |
| ATT\&CK Tactic    | Command and Control (TA0011) |
| ATT\&CK Technique | Protocol Tunneling (T1572)   |
| Severity          | Informational                |

**Description**

An uncommon network tunnel was established using ACS\_ssh.exe.

**Attacker's Goals**

Attackers may use SSH or any similar utility to create a network tunnel to allow an attacker to covertly connect to an internal host.

**Investigative actions**

* Review the external IP/domain using known intelligence tools.
* Investigate the causality of the process and its user ID to find uncommon behaviors.
* Search for processes or files that were created by this SSH instance.

</details>

<details>

<summary>Uncommon SSH tunnel to unpopular IP address</summary>

**Synopsis**

| Field             | Value                        |
| ----------------- | ---------------------------- |
| ATT\&CK Tactic    | Command and Control (TA0011) |
| ATT\&CK Technique | Protocol Tunneling (T1572)   |
| Severity          | Low                          |

**Description**

An uncommon SSH tunnel was established to an unpopular remote IP address at the organization.

**Attacker's Goals**

Attackers may use SSH or any similar utility to create a network tunnel to allow an attacker to covertly connect to an internal host.

**Investigative actions**

* Review the external IP/domain using known intelligence tools.
* Investigate the causality of the process and its user ID to find uncommon behaviors.
* Search for processes or files that were created by this SSH instance.

</details>

<details>

<summary>An uncommon network tunnel was established over the default SSH port</summary>

**Synopsis**

| Field             | Value                        |
| ----------------- | ---------------------------- |
| ATT\&CK Tactic    | Command and Control (TA0011) |
| ATT\&CK Technique | Protocol Tunneling (T1572)   |
| Severity          | Low                          |

**Description**

An unpopular process and command line created a network tunnel over the default SSH port.

**Attacker's Goals**

Attackers may use SSH or any similar utility to create a network tunnel to allow an attacker to covertly connect to an internal host.

**Investigative actions**

* Review the external IP/domain using known intelligence tools.
* Investigate the causality of the process and its user ID to find uncommon behaviors.
* Search for processes or files that were created by this SSH instance.

</details>


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