Allow Inbound Traffic In Firewall Rule
The following analytic detects a suspicious PowerShell command that allows inbound traffic to a specific local port within the public profile. It leverages PowerShell script block logging (EventCode 4104) to identify…
Description
The following analytic detects a suspicious PowerShell command that allows inbound traffic to a specific local port within the public profile. It leverages PowerShell script block logging (EventCode 4104) to identify commands containing keywords like "firewall," "Inbound," "Allow," and "-LocalPort." This activity is significant because it may indicate an attacker attempting to establish remote access by modifying firewall rules. If confirmed malicious, this could allow unauthorized access to the machine, potentially leading to further exploitation and data exfiltration.
Detection logic
Detection requirements
- Platform
- Windows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- powershell_script_block_logging_4104
Known benign triggers
- administrator may allow inbound traffic in certain network or machine.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| docs.microsoft.com/en-us/powershell/module/netsecurity/new-netfirewallrule?view=windowsserver2019-ps | 2 |
From the source
- At source
- Open at source
- Upstream identifier
- a5d85486-b89c-11eb-8267-acde48001122
- Tagged by the source as
- NetSupport RMM Tool AbuseProhibited Traffic Allowed or Protocol MismatchEndpointendpointSplunk CloudSplunk EnterpriseSplunk Enterprise Securityendpoint
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Aug 26, 2026
- Version
- 1