Name:Windows Indirect Command Execution Via Series Of Forfiles id:bfdaabe7-3db8-48c5-80c1-220f9b8f22be version:5 date:2024-11-13 author:Teoderick Contreras, Splunk status:production type:Anomaly Description:The following analytic detects excessive usage of the forfiles.exe process, which is often indicative of post-exploitation activities. The detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs that include process GUID, process name, and parent process. This activity is significant because forfiles.exe can be abused to execute commands on multiple files, a technique used by ransomware like Prestige. If confirmed malicious, this behavior could allow attackers to enumerate files, potentially leading to data exfiltration or further malicious actions. Data_source:
-Sysmon EventID 1
-Windows Event Log Security 4688
-CrowdStrike ProcessRollup2
search:| tstats `security_content_summariesonly` values(Processes.action) as action values(Processes.original_file_name) as original_file_name values(Processes.parent_process_exec) as parent_process_exec values(Processes.parent_process_guid) as parent_process_guid values(Processes.parent_process_id) as parent_process_id values(Processes.parent_process_path) as parent_process_path values(Processes.process) as process values(Processes.process_exec) as process_exec values(Processes.process_guid) as process_guid values(Processes.process_hash) as process_hash values(Processes.process_id) as process_id values(Processes.process_integrity_level) as process_integrity_level values(Processes.process_name) as process_name values(Processes.process_path) as process_path values(Processes.user) as user values(Processes.user_id) as user_id values(Processes.vendor_product) as vendor_product count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name = "forfiles.exe" OR Processes.original_file_name = "forfiles.exe" by Processes.parent_process_name Processes.parent_process Processes.dest Processes.user _time span=1m | where count >=20 | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_indirect_command_execution_via_series_of_forfiles_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:unknown References: -https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/forfiles -https://github.com/carlospolop/PEASS-ng/tree/master/winPEAS -https://www.microsoft.com/en-us/security/blog/2022/10/14/new-prestige-ransomware-impacts-organizations-in-ukraine-and-poland/ 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 Post-Exploitation' - 'Prestige Ransomware' asset_type:Endpoint mitre_attack_id: - 'T1202' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' security_domain:endpoint
