Name:Office Product Spawning CertUtil id:6925fe72-a6d5-11eb-9e17-acde48001122 version:8 date:2024-11-28 author:Michael Haag, Splunk status:production type:TTP Description:The following analytic detects any Windows Office Product spawning `certutil.exe`, a behavior often associated with malware families like TA551 and IcedID. This detection leverages Endpoint Detection and Response (EDR) data, focusing on process relationships and command-line executions. The significance lies in the fact that `certutil.exe` is frequently used for downloading malicious payloads from remote URLs. If confirmed malicious, this activity could lead to unauthorized code execution, data exfiltration, or further system compromise. Immediate investigation and containment are crucial to prevent potential damage. 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.parent_process_name IN ("winword.exe","excel.exe","powerpnt.exe","mspub.exe","visio.exe","onenote.exe","onenotem.exe","onenoteviewer.exe","onenoteim.exe","msaccess.exe", "Graph.exe","winproj.exe") `process_certutil` by Processes.dest Processes.user Processes.parent_process_name Processes.parent_process Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)` | `office_product_spawning_certutil_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:No false positives known. Filter as needed. References: -https://redcanary.com/threat-detection-report/threats/TA551/ -https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1105/T1105.md -https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/trojanized-onenote-document-leads-to-formbook-malware/ 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: - 'Spearphishing Attachments' - 'Trickbot' - 'Compromised Windows Host' - 'AgentTesla' - 'CVE-2023-36884 Office and Windows HTML RCE Vulnerability' asset_type:Endpoint confidence:90 impact:70 message:office parent process $parent_process_name$ will execute a suspicious child process $process_name$ with process id $process_id$ in host $dest$ mitre_attack_id: - 'T1566' - 'T1566.001' observable: name:'dest' type:'Hostname' - role: - 'Victim' name:'process_name' type:'Process Name' - 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:63 security_domain:endpoint
