Name:Windows Steal Authentication Certificates Export PfxCertificate id:391329f3-c14b-4b8d-8b37-ac5012637360 version:4 date:2024-09-30 author:Michael Haag, Splunk status:production type:Anomaly Description:The following analytic detects the use of the PowerShell cmdlet `export-pfxcertificate` on the command line, indicating an attempt to export a certificate from the local Windows Certificate Store. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs and command-line arguments. This activity is significant as it may indicate an attempt to exfiltrate authentication certificates, which can be used to impersonate users or decrypt sensitive data. If confirmed malicious, this could lead to unauthorized access and potential data breaches. 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="*export-pfxcertificate*" by Processes.dest Processes.user Processes.parent_process_name 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_steal_authentication_certificates_export_pfxcertificate_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:Filtering may be requried based on automated utilities and third party applications that may export certificates. References: -https://dev.to/iamthecarisma/managing-windows-pfx-certificates-through-powershell-3pj -https://learn.microsoft.com/en-us/powershell/module/pki/export-pfxcertificate?view=windowsserver2022-ps 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: - 'Windows Certificate Services' asset_type:Endpoint confidence:60 impact:60 message:An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting to export a certificate from the local Windows Certificate Store. mitre_attack_id: - 'T1649' observable: name:'user' type:'User' - role: - 'Victim' name:'dest' type:'Hostname' - role: - 'Victim' name:'parent_process_name' type:'Process' - role: - 'Attacker' name:'process_name' type:'Process' - role: - 'Attacker' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'Processes.dest' - 'Processes.user' - 'Processes.parent_process_name' - 'Processes.parent_process' - 'Processes.original_file_name' - 'Processes.process_name' - 'Processes.process' - 'Processes.process_id' - 'Processes.parent_process_path' - 'Processes.process_path' - 'Processes.parent_process_id' risk_score:36 security_domain:endpoint
