Name:Windows PowerShell Export PfxCertificate id:ed06725f-6da6-439f-9dcc-ab30e891297c version:3 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` by leveraging Script Block Logging. This activity is significant as it may indicate an adversary attempting to exfiltrate certificates from the Windows Certificate Store. Monitoring this behavior is crucial for identifying potential certificate theft, which can lead to unauthorized access and impersonation attacks. If confirmed malicious, this activity could allow attackers to compromise secure communications, authenticate as legitimate users, and escalate their privileges within the network. Data_source:
-Powershell Script Block Logging 4104
search:`powershell` EventCode=4104 ScriptBlockText IN ("*export-pfxcertificate*") | rename Computer as dest | stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText dest user_id | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_powershell_export_pfxcertificate_filter`
how_to_implement:To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell. known_false_positives:It is possible administrators or scripts may run these commands, filtering may be required. 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 - "$dest$"' 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: - 'Windows Certificate Services' asset_type:Endpoint confidence:60 impact:60 message:A PowerShell Cmdlet related to exporting a PFX Certificate was ran on $dest$, attempting to export a certificate. mitre_attack_id: - 'T1552.004' - 'T1552' - 'T1649' observable: name:'dest' type:'Hostname' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'ScriptBlockText' - 'dest' - 'EventCode' risk_score:36 security_domain:endpoint
