This analytic detects a potential suspicious modification of firewall rule allowing to execute specific application. This technique was identified when an adversary and red teams to bypassed firewall file execution restriction in a targetted host. Take note that this event or command can run by administrator during testing or allowing legitimate tool or application.
- Type: Anomaly
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2021-11-12
- Author: Teoderick Contreras, Splunk
- ID: 9a8f63a8-43ac-11ec-904c-acde48001122
Kill Chain Phase
1 2 3 4 5 6 | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process = "*firewall*" Processes.process = "*allow*" Processes.process = "*add*" Processes.process = "*ENABLE*" by Processes.dest Processes.user Processes.parent_process_name Processes.parent_process Processes.process_name Processes.process Processes.process_id Processes.parent_process_id | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `firewall_allowed_program_enable_filter`
The SPL above uses the following Macros:
firewall_allowed_program_enable_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the
Endpoint datamodel in the
Processes node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.
Known False Positives
A network operator or systems administrator may utilize an automated or manual execution of this firewall rule that may generate false positives. Filter as needed.
Associated Analytic Story
|25.0||50||50||firewall allowed program commandline $process$ of $process_name$ on $dest$ by $user$|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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