Port Sweep

Synopsis

Field	Value
Activation Period	14 Days
Training Period	30 Days
Test Period	1 Hour
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
ATT&CK Tactic	Discovery (TA0007)
ATT&CK Technique	Network Service Discovery (T1046)
Severity	Informational

Description

The endpoint connected, or attempted to connect, to multiple hosts using privileged ports that serve a well-defined function. Attackers perform port sweep for reconnaissance purposes, to find computers or servers that accept connections on these ports, and to find vulnerable services that can be exploited. Coverage for port sweeps using data arriving solely from Cortex agents is incomplete.

Attacker's Goals

An attacker is determining which ports are open or closed on remote endpoints in an attempt to identify the endpoint operating system, firewall configuration, and exploitable services.

Investigative actions

• Ensure that the source of the port sweep is not a new server in the network. New domain controllers or servers hosting services such as SNMP can cause false positives.
• Check for new known vulnerabilities in the ports scanned, this method is often used to target known vulnerabilities.

Variations

Port Sweep to multiple subnets

Synopsis

Field	Value
ATT&CK Tactic	Discovery (TA0007)
ATT&CK Technique	Network Service Discovery (T1046)
Severity	Low

Description

The endpoint connected, or attempted to connect, to multiple hosts using privileged ports that serve a well-defined function. Attackers perform port sweep for reconnaissance purposes, to find computers or servers that accept connections on these ports, and to find vulnerable services that can be exploited. Coverage for port sweeps using data arriving solely from Cortex agents is incomplete.

Attacker's Goals

An attacker is determining which ports are open or closed on remote endpoints in an attempt to identify the endpoint operating system, firewall configuration, and exploitable services.

Investigative actions

• Ensure that the source of the port sweep is not a new server in the network. New domain controllers or servers hosting services such as SNMP can cause false positives.
• Check for new known vulnerabilities in the ports scanned, this method is often used to target known vulnerabilities.