Name:Windows ConHost with Headless Argument id:d5039508-998d-4cfc-8b5e-9dcd679d9a62 version:4 date:2024-11-28 author:Michael Haag, Splunk status:production type:TTP Description:The following analytic detects the unusual invocation of the Windows Console Host process (conhost.exe) with the undocumented --headless parameter. This detection leverages Endpoint Detection and Response (EDR) telemetry, specifically monitoring for command-line executions where conhost.exe is executed with the --headless argument. This activity is significant for a SOC as it is not commonly used in legitimate operations and may indicate an attacker's attempt to execute commands stealthily. If confirmed malicious, this behavior could lead to persistence, lateral movement, or other malicious activities, potentially resulting in data exfiltration or system compromise. 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 Processes.process_name=conhost.exe Processes.process="*--headless *" by Processes.dest Processes.user 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)` | `windows_conhost_with_headless_argument_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:False positives may be present if the application is legitimately used, filter by user or endpoint as needed. References: -https://x.com/embee_research/status/1559410767564181504?s=20 -https://x.com/GroupIB_TI/status/1719675754886131959?s=20 drilldown_searches: name:'View the detection results for - "$user$" and "$dest$"' search:'%original_detection_search% | search user = "$user$" dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$user$" and "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") 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: - 'Spearphishing Attachments' - 'Compromised Windows Host' asset_type:Endpoint atomic_guid: confidence:70 impact:100 message:Windows ConHost with Headless Argument detected on $dest$ by $user$. mitre_attack_id: - 'T1564.003' - 'T1564.006' observable: name:'user' type:'User' - role: - 'Victim' name:'dest' type:'Hostname' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' risk_score:70 required_fields: - 'Processes.dest' - 'Processes.user' - 'Processes.parent_process' - 'Processes.process_name' - 'Processes.process' - 'Processes.process_id' - 'Processes.parent_process_id' security_domain:endpoint
