name: MSBuild Suspicious Spawned By Script Process id: 213b3148-24ea-11ec-93a2-acde48001122 version: 1 date: '2021-10-04' author: Teoderick Contreras, Splunk status: production type: TTP description: This analytic is to detect a suspicious child process of MSBuild spawned by Windows Script Host - cscript or wscript. This behavior or event are commonly seen and used by malware or adversaries to execute malicious msbuild process using malicious script in the compromised host. During triage, review parallel processes and identify any file modifications. MSBuild may load a script from the same path without having command-line arguments. data_source: - Sysmon Event ID 1 search: selection1: ParentImage: - wscript.exe - cscript.exe selection2: OriginalFileName: MSBuild.exe selection3: Image|endswith: msbuild.exe condition: selection1 and selection2 and selection3 how_to_implement: To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the `Endpoint` datamodel in the `Processes` node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product. 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/ 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 risk_score: 49 security_domain: endpoint tests: - name: True Positive Test attack_data: - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1127.001/regsvr32_silent/sysmon.log source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational sourcetype: xmlwineventlog