Name:Detect Renamed PSExec id:683e6196-b8e8-11eb-9a79-acde48001122 version:8 date:2024-10-17 author:Michael Haag, Splunk, Alex Oberkircher, Github Community status:production type:Hunting Description:The following analytic identifies instances where `PsExec.exe` has been renamed and executed on an endpoint. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and original file names. This activity is significant because renaming `PsExec.exe` is a common tactic to evade detection. If confirmed malicious, this could allow an attacker to execute commands remotely, potentially leading to unauthorized access, lateral movement, or further compromise of the network. 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!=psexec.exe AND Processes.process_name!=psexec64.exe) AND Processes.original_file_name=psexec.c by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id Processes.original_file_name | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `detect_renamed_psexec_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:Limited false positives should be present. It is possible some third party applications may use older versions of PsExec, filter as needed. References: -https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1569.002/T1569.002.yaml -https://redcanary.com/blog/threat-hunting-psexec-lateral-movement/ drilldown_searches:
: tags: analytic_story: - 'SamSam Ransomware' - 'DHS Report TA18-074A' - 'HAFNIUM Group' - 'DarkSide Ransomware' - 'Active Directory Lateral Movement' - 'CISA AA22-320A' - 'Sandworm Tools' - 'BlackByte Ransomware' - 'DarkGate Malware' - 'Rhysida Ransomware' asset_type:Endpoint confidence:90 impact:30 message:The following $process_name$ has been identified as renamed, spawning from $parent_process_name$ on $dest$ by $user$. mitre_attack_id: - 'T1569' - 'T1569.002' 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:27 security_domain:endpoint
