Name:PowerShell Invoke CIMMethod CIMSession id:651ee958-a433-471c-b264-39725b788b83 version:12 date:None author:Michael Haag, Splunk status:production type:Anomaly Description:The following analytic detects the creation of a New-CIMSession cmdlet followed by the use of the Invoke-CIMMethod cmdlet within PowerShell. It leverages PowerShell Script Block Logging to identify these specific cmdlets in the ScriptBlockText field. This activity is significant because it mirrors the behavior of the Invoke-WMIMethod cmdlet, often used for remote code execution via NTLMv2 pass-the-hash authentication. If confirmed malicious, this could allow an attacker to execute commands remotely, potentially leading to unauthorized access and control over targeted systems. Data_source:
-Powershell Script Block Logging 4104
search:`powershell` EventCode=4104 ScriptBlockText IN ("*invoke-CIMMethod*", "*New-CimSession*")
| fillnull
| stats count min(_time) as firstTime max(_time) as lastTime BY dest signature signature_id user_id vendor_product EventID Guid Opcode Name Path ProcessID ScriptBlockId ScriptBlockText
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `powershell_invoke_cimmethod_cimsession_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://help.splunk.com/en/security-offerings/splunk-user-behavior-analytics/get-data-in/5.4.1/add-other-data-to-splunk-uba/configure-powershell-logging-to-see-powershell-anomalies-in-splunk-uba. known_false_positives:False positives may be present based on third-party applications or administrators using CIM. It is recommended to apply appropriate filters as needed to minimize the number of false positives. References: -https://learn.microsoft.com/en-us/powershell/module/cimcmdlets/invoke-cimmethod?view=powershell-7.3 drilldown_searches: name:'View the detection results for - "$Computer$"' search:'%original_detection_search% | search Computer = "$Computer$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$Computer$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$Computer$") | 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:'7d' latest_offset:'0' analytic_story:['Scattered Lapsus$ Hunters', 'Malicious PowerShell', 'Active Directory Lateral Movement']
