IMPORTANT: No additional bug fixes or documentation updates
will be released for this version. For the latest information, see the
current release documentation.
Port Forwarding Rule Addition
editPort Forwarding Rule Addition
editIdentifies the creation of a new port forwarding rule. An adversary may abuse this technique to bypass network segmentation restrictions.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.*
- logs-windows.*
Severity: medium
Risk score: 47
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Command and Control
Version: 6
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guide
edit## Triage and analysis ### Investigating Port Forwarding Rule Addition Network port forwarding is a mechanism to redirect incoming TCP connections (IPv4 or IPv6) from the local TCP port to any other port number, or even to a port on a remote computer. Attackers may configure port forwarding rules to bypass network segmentation restrictions, using the host as a jump box to access previously unreachable systems. This rule monitors the modifications to the `HKLM\SYSTEM\*ControlSet*\Services\PortProxy\v4tov4\` subkeys. #### Possible investigation steps - Investigate the process execution chain (parent process tree). - Identify the user account that performed the action and whether it should perform this kind of action. - Contact the account owner and confirm whether they are aware of this activity. - Investigate other alerts associated with the user/host during the past 48 hours. - Check for similar behavior in other hosts on the environment. - Identify the target host IP address, verify if connections were made from the host where the modification occurred, and check what credentials were used to perform it. - Investigate suspicious login activity, such as unauthorized access and logins from outside working hours and unusual locations. ### False positive analysis - This mechanism can be used legitimately. Analysts can dismiss the alert if the Administrator is aware of the activity and there are justifications for this configuration. - If this activity is expected and noisy in your environment, consider adding exceptions — preferably with a combination of user and command line conditions. ### Response and remediation - Initiate the incident response process based on the outcome of the triage. - Delete the port forwarding rule. - Isolate the involved host to prevent further post-compromise behavior. - If potential malware or credential compromise activities were discovered during the alert triage, activate the respective incident response plan. ## Config If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.
Rule query
editregistry where registry.path : "HKLM\\SYSTEM\\*ControlSet*\\Services\\PortProxy\\v4tov4\\*"
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Command and Control
- ID: TA0011
- Reference URL: https://attack.mitre.org/tactics/TA0011/
-
Technique:
- Name: Protocol Tunneling
- ID: T1572
- Reference URL: https://attack.mitre.org/techniques/T1572/