> 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-ssh-session-was-established.md).
# Uncommon SSH 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 | Requires one of the following data sources:
Palo Alto Networks Firewall traffic Logs OR XDR Agent OR Third-Party Firewalls
|
| Detector Tags | NDR Lateral Movement Analytics |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
### Description
An uncommon SSH session 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
An Uncommon SSH session was established using a rare server HASSH for the ssh server
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
An Uncommon SSH session was established using a rare server HASSH for the ssh server.
**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.
An Uncommon SSH session was established using a rare client HASSH for the agent
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
An uncommon SSH session was established using a rare client HASSH for the agent.
**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.
An Uncommon SSH session was established using a rare request banner for the agent
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
An Uncommon SSH session was established using a rare request banner for the agent.
**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.
An Uncommon SSH session was established using a rare Response banner for the ssh server
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
An Uncommon SSH session was established using a rare Response banner for the ssh server.
**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.
An Uncommon SSH session was established using a rare Response banner
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
An Uncommon SSH session was established using a rare Response banner.
**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.
An Uncommon SSH session was established using a rare request banner
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
An Uncommon SSH session was established using a rare request banner.
**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.
An Uncommon SSH session was established using a rare Client HASSH
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
An uncommon SSH session was established using a rare client HASSH.
**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.
An Uncommon SSH session was established using a rare Server HASSH
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
An Uncommon SSH session was established using a rare Server HASSH.
**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.
A suspicious SSH session was established
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
A suspicious SSH session was established to a globally rare external IP using a nonstandard 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.
An Uncommon SSH session was established to a rare IP address
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
An uncommon SSH session was established to a rare remote IP address.
**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.
An Uncommon SSH session was established using a nonstandard SSH port
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
An uncommon SSH session was established with a destination port using a nonstandard 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.
Uncommon SSH session was established to a rare internal IP
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
An uncommon SSH session was established to a rare internal IP.
**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.
Uncommon SSH session was established that involved a higher than usual volume
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Low |
**Description**
Uncommon SSH session was established that involved a higher than usual volume.
**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.
Uncommon SSH session was established to an internal IP
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Non-Standard Port (T1571) |
| Severity | Informational |
**Description**
An uncommon SSH session was established to an internal IP.
**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.
---
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