cscli scenarios install sigmahq/proc_creation_win_userinit_uncommon_child_processes1type: trigger2name: sigmahq/proc_creation_win_userinit_uncommon_child_processes3description: |4 Detects uncommon "userinit.exe" child processes, which could be a sign of uncommon shells or login scripts used for persistence.5filter: |6 (evt.Meta.service == 'sysmon' && evt.Parsed.EventID == '1') && (evt.Parsed.ParentImage endsWith '\\userinit.exe' && not (evt.Parsed.Image endsWith ':\\WINDOWS\\explorer.exe') && not (evt.Parsed.CommandLine contains 'netlogon.bat' || evt.Parsed.CommandLine contains 'UsrLogon.cmd' || evt.Parsed.CommandLine == 'PowerShell.exe' || evt.Parsed.Image endsWith ':\\Windows\\System32\\proquota.exe' || evt.Parsed.Image endsWith ':\\Windows\\SysWOW64\\proquota.exe' || evt.Parsed.Image endsWith ':\\Program Files (x86)\\Citrix\\HDX\\bin\\cmstart.exe' || evt.Parsed.Image endsWith ':\\Program Files (x86)\\Citrix\\HDX\\bin\\icast.exe' || evt.Parsed.Image endsWith ':\\Program Files (x86)\\Citrix\\System32\\icast.exe' || evt.Parsed.Image endsWith ':\\Program Files\\Citrix\\HDX\\bin\\cmstart.exe' || evt.Parsed.Image endsWith ':\\Program Files\\Citrix\\HDX\\bin\\icast.exe' || evt.Parsed.Image endsWith ':\\Program Files\\Citrix\\System32\\icast.exe' || evt.Parsed.Image == ''))7blackhole: 2m8#status: test9labels:10 service: windows11 confidence: 112 spoofable: 013 classification:14 - attack.t1037.0011516 label: "Uncommon Userinit Child Process"17 behavior : "windows:audit"18 remediation: false1920scope:21 type: ParentProcessId22 expression: evt.Parsed.ParentProcessId2324