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.