> 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-recurring-rare-external-host-access.md).
# Uncommon recurring rare external host access
### Synopsis
| Field | Value |
| -------------------- | ----------------------------------------------------------------------------------------------------- |
| Activation Period | 14 Days |
| Training Period | 30 Days |
| Test Period | N/A (single event) |
| Deduplication Period | 14 Days |
| Required Data | XDR Agent |
| Detector Tags | Abnormal Communication Analytics |
| ATT\&CK Tactic | Command and Control (TA0011), Exfiltration (TA0010) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Exfiltration Over C2 Channel (T1041), Remote Access Tools (T1219) |
| Severity | Informational |
### Description
A process has established recurring connections to an uncommon external host.
### Attacker's Goals
Communicate with malware running on your network to control malware activities, perform software updates on the malware, or to take inventory of infected machines. Additionally, establish command and control channels for remote malware control, conduct discovery activities to gather information about the target environment, or exfiltrate sensitive data from compromised systems.
### Investigative actions
* Identify the process contacting the remote host and determine whether the traffic is malicious.
* Look for other endpoints on your network that are also periodically contacting the same external host.
* Inspect the domain or URL for malicious indicators or its presence in threat intelligence feeds and reputation lists.
### Variations
Uncommon recurring rare external host access by an automated penetration testing tool
**Synopsis**
| Field | Value |
| ----------------- | ----------------------------------------------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011), Exfiltration (TA0010) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Exfiltration Over C2 Channel (T1041), Remote Access Tools (T1219) |
| Severity | High |
**Description**
A process has established recurring connections to an uncommon external host.
**Attacker's Goals**
Communicate with malware running on your network to control malware activities, perform software updates on the malware, or to take inventory of infected machines. Additionally, establish command and control channels for remote malware control, conduct discovery activities to gather information about the target environment, or exfiltrate sensitive data from compromised systems.
**Investigative actions**
* Identify the process contacting the remote host and determine whether the traffic is malicious.
* Look for other endpoints on your network that are also periodically contacting the same external host.
* Inspect the domain or URL for malicious indicators or its presence in threat intelligence feeds and reputation lists.
Uncommon recurring rare external host access to a dynamic DNS domain
**Synopsis**
| Field | Value |
| ----------------- | ----------------------------------------------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011), Exfiltration (TA0010) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Exfiltration Over C2 Channel (T1041), Remote Access Tools (T1219) |
| Severity | Low |
**Description**
A process has established recurring connections to an uncommon external host.
**Attacker's Goals**
Communicate with malware running on your network to control malware activities, perform software updates on the malware, or to take inventory of infected machines. Additionally, establish command and control channels for remote malware control, conduct discovery activities to gather information about the target environment, or exfiltrate sensitive data from compromised systems.
**Investigative actions**
* Identify the process contacting the remote host and determine whether the traffic is malicious.
* Look for other endpoints on your network that are also periodically contacting the same external host.
* Inspect the domain or URL for malicious indicators or its presence in threat intelligence feeds and reputation lists.
Uncommon recurring rare external host access initiated by a cron job
**Synopsis**
| Field | Value |
| ----------------- | ---------------------------------------------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011), Execution (TA0002), Persistence (TA0003), Exfiltration (TA0010) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Scheduled Task/Job: Cron (T1053.003), Scheduled Transfer (T1029) |
| Severity | Low |
**Description**
A process has established recurring connections to an uncommon external host.
**Attacker's Goals**
Communicate with malware running on your network to control malware activities, perform software updates on the malware, or to take inventory of infected machines. Additionally, establish command and control channels for remote malware control, conduct discovery activities to gather information about the target environment, or exfiltrate sensitive data from compromised systems.
**Investigative actions**
* Identify the process contacting the remote host and determine whether the traffic is malicious.
* Look for other endpoints on your network that are also periodically contacting the same external host.
* Inspect the domain or URL for malicious indicators or its presence in threat intelligence feeds and reputation lists.
Uncommon recurring rare external host access with a rare top-level domain
**Synopsis**
| Field | Value |
| ----------------- | ----------------------------------------------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011), Exfiltration (TA0010) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Exfiltration Over C2 Channel (T1041), Remote Access Tools (T1219) |
| Severity | Low |
**Description**
A process has established recurring connections to an uncommon external host.
**Attacker's Goals**
Communicate with malware running on your network to control malware activities, perform software updates on the malware, or to take inventory of infected machines. Additionally, establish command and control channels for remote malware control, conduct discovery activities to gather information about the target environment, or exfiltrate sensitive data from compromised systems.
**Investigative actions**
* Identify the process contacting the remote host and determine whether the traffic is malicious.
* Look for other endpoints on your network that are also periodically contacting the same external host.
* Inspect the domain or URL for malicious indicators or its presence in threat intelligence feeds and reputation lists.
Uncommon recurring rare external host access using an exfiltration tool
**Synopsis**
| Field | Value |
| ----------------- | ----------------------------------------------------------------------------------------------------- |
| ATT\&CK Tactic | Command and Control (TA0011), Exfiltration (TA0010) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Exfiltration Over C2 Channel (T1041), Remote Access Tools (T1219) |
| Severity | Low |
**Description**
A process has established recurring connections to an uncommon external host.
**Attacker's Goals**
Communicate with malware running on your network to control malware activities, perform software updates on the malware, or to take inventory of infected machines. Additionally, establish command and control channels for remote malware control, conduct discovery activities to gather information about the target environment, or exfiltrate sensitive data from compromised systems.
**Investigative actions**
* Identify the process contacting the remote host and determine whether the traffic is malicious.
* Look for other endpoints on your network that are also periodically contacting the same external host.
* Inspect the domain or URL for malicious indicators or its presence in threat intelligence feeds and reputation lists.
Uncommon recurring rare external host access with a sensitive file in actor or causality command line
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| ATT\&CK Tactic | Exfiltration (TA0010), Credential Access (TA0006), Discovery (TA0007), Command and Control (TA0011) |
| ATT\&CK Technique | Application Layer Protocol (T1071), Exfiltration Over C2 Channel (T1041), Steal Application Access Token (T1528), System Owner/User Discovery (T1033), OS Credential Dumping (T1003) |
| Severity | Low |
**Description**
A process has established recurring connections to an uncommon external host.
**Attacker's Goals**
Communicate with malware running on your network to control malware activities, perform software updates on the malware, or to take inventory of infected machines. Additionally, establish command and control channels for remote malware control, conduct discovery activities to gather information about the target environment, or exfiltrate sensitive data from compromised systems.
**Investigative actions**
* Identify the process contacting the remote host and determine whether the traffic is malicious.
* Look for other endpoints on your network that are also periodically contacting the same external host.
* Inspect the domain or URL for malicious indicators or its presence in threat intelligence feeds and reputation lists.
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:
```
GET https://cortex-docs.paloaltonetworks.com/analytics-alerts/alerts-by-name/uncommon-recurring-rare-external-host-access.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.