Name:MSBuild Suspicious Spawned By Script Process id:213b3148-24ea-11ec-93a2-acde48001122 version:3 date:2024-09-30 author:Teoderick Contreras, Splunk status:production type:TTP Description:The following analytic detects the suspicious spawning of MSBuild.exe by Windows Script Host processes (cscript.exe or wscript.exe). This behavior is often associated with malware or adversaries executing malicious MSBuild processes via scripts on compromised hosts. The detection leverages Endpoint Detection and Response (EDR) telemetry, focusing on process creation events where MSBuild is a child of script hosts. This activity is significant as it may indicate an attempt to execute malicious code. If confirmed malicious, it could lead to unauthorized code execution, potentially compromising the host and allowing further malicious activities. Data_source:
-Sysmon EventID 1
-Windows Event Log Security 4688
-CrowdStrike ProcessRollup2
search:| tstats `security_content_summariesonly` count values(Processes.process_name) as process_name values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name IN ("wscript.exe", "cscript.exe") AND `process_msbuild` by Processes.dest Processes.parent_process Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.user | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `msbuild_suspicious_spawned_by_script_process_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:False positives should be limited as developers do not spawn MSBuild via a WSH. References: -https://app.any.run/tasks/dc93ee63-050c-4ff8-b07e-8277af9ab939/ drilldown_searches: name:'View the detection results for - "$dest$" and "$user$"' search:'%original_detection_search% | search dest = "$dest$" user = "$user$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$" and "$user$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user$") 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: - 'Trusted Developer Utilities Proxy Execution MSBuild' asset_type:Endpoint confidence:70 impact:70 message:Msbuild.exe process spawned by $parent_process_name$ on $dest$ executed by $user$ mitre_attack_id: - 'T1127.001' - 'T1127' observable: name:'dest' type:'Endpoint' - role: - 'Victim' name:'user' type:'User' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'Processes.dest' - 'Processes.parent_process' - 'Processes.parent_process_name' - 'Processes.process_name' - 'Processes.original_file_name' - 'Processes.user' risk_score:49 security_domain:endpoint
