Name:Windows File Share Discovery With Powerview id:a44c0be1-d7ab-41e4-92fd-aa9af4fe232c version:3 date:2024-09-30 author:Mauricio Velazco, Splunk status:production type:TTP Description:The following analytic detects the execution of the Invoke-ShareFinder PowerShell cmdlet from PowerView. This detection leverages PowerShell Script Block Logging to identify instances where this specific command is executed. Monitoring this activity is crucial as it indicates an attempt to enumerate network file shares, which may contain sensitive information such as backups, scripts, and credentials. If confirmed malicious, this activity could enable an attacker to escalate privileges or move laterally within the network, potentially compromising additional systems and sensitive data. Data_source:
-Powershell Script Block Logging 4104
search:`powershell` EventCode=4104 (ScriptBlockText=Invoke-ShareFinder*) | stats count min(_time) as firstTime max(_time) as lastTime by Opcode Computer UserID EventCode ScriptBlockText | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_file_share_discovery_with_powerview_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:Security teams may leverage PowerView proactively to identify and remediate sensitive file shares. Filter as needed. References: -https://github.com/PowerShellEmpire/PowerTools/blob/master/PowerView/powerview.ps1 -https://thedfirreport.com/2023/01/23/sharefinder-how-threat-actors-discover-file-shares/ -https://attack.mitre.org/techniques/T1135/ drilldown_searches: name:'View the detection results for - "$Computer$" and "$UserID$"' search:'%original_detection_search% | search Computer = "$Computer$" UserID = "$UserID$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$Computer$" and "$UserID$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$Computer$", "$UserID$") 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: - 'Active Directory Privilege Escalation' - 'Active Directory Discovery' asset_type:Endpoint confidence:80 context: - 'Source:Endpoint' - 'Stage:Privilege Escalation' impact:60 message:Invoke-ShareFinder commandlet was executed on $Computer$ mitre_attack_id: - 'T1135' observable: name:'Computer' type:'Hostname' - role: - 'Victim' name:'UserID' type:'User' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'EventCode' - 'ScriptBlockText' - 'Opcode' - 'Computer' - 'UserID' risk_score:48 security_domain:endpoint
