Name:Windows Delete or Modify System Firewall id:b188d11a-eba7-419d-b8b6-cc265b4f2c4f version:4 date:2024-09-30 author:Teoderick Contreras, Splunk status:production type:Anomaly Description:The following analytic identifies 'netsh' processes that delete or modify firewall configurations. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions containing specific keywords. This activity is significant because it can indicate malware, such as NJRAT, attempting to alter firewall settings to evade detection or remove traces. If confirmed malicious, this behavior could allow an attacker to disable security measures, facilitating further compromise and persistence within the network. Data_source:
-Sysmon EventID 1
-Windows Event Log Security 4688
-CrowdStrike ProcessRollup2
search:| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_netsh` Processes.process = "* firewall *" Processes.process = "* del*" by Processes.parent_process Processes.parent_process_name Processes.process_name Processes.process_id Processes.process_guid Processes.process Processes.user Processes.dest | `drop_dm_object_name("Processes")` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_delete_or_modify_system_firewall_filter`
how_to_implement:The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process. known_false_positives:Administrator may modify or delete firewall configuration. References: -https://malpedia.caad.fkie.fraunhofer.de/details/win.njrat drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'NjRAT' - 'ShrinkLocker' asset_type:Endpoint confidence:60 impact:60 message:A $process_name$ deleted a firewall configuration on $dest$ mitre_attack_id: - 'T1562' - 'T1562.004' observable: name:'dest' type:'Endpoint' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' risk_score:36 required_fields: - '_time' - 'Processes.dest' - 'Processes.user' - 'Processes.parent_process_name' - 'Processes.parent_process' - 'Processes.process_name' - 'Processes.process' - 'Processes.process_id' - 'Processes.parent_process_id' security_domain:endpoint
