Query: rule covering Detects uncommon "userinit.exe" child processes, which could be a sign of uncommon shells or login scripts used for pers
Matching passage: Sigma rule: Detects uncommon "userinit.exe" child processes, which could be a sign of uncommon shells or login scripts used for pers. Logsource: windows / process_creation. Rule: title: Uncommon Userinit Child Process id: 0a98a10c-685d-4ab0-bddc-b6bdd1d48458 related: - id: 21d856f9-9281-4ded-9377-51a1a6e2a432 type: similar status: test description: Detects uncommon "userinit.exe" child processes, which could be a sign of uncommon shells or login scripts used for persistence. references: - https://cocomelonc.github.io/persistence/2022/12/09/malware-pers-20.html - https://learn.microsoft.com/en-us/windows-server/administration/server-core/server-core-sconfig#powershell-is-the-default-shell-on-server-core author: Tom Ueltschi (@c_APT_ure), Tim Shelton date: 2019-01-12 modified: 2023-11-14 tags: - attack.privilege-escalation - attack.t1037.001 - attack.persistence logsource: category: process_creation product: windows detection: selection: ParentImage|endswith: \userinit.exe filter_main_explorer: Image|endswith: :\WINDOWS\explorer.exe filter_optional_logonscripts: CommandLine|contains: - netlogon.bat - UsrLogon.cmd filter_optional_windows_core: CommandLine: PowerShell.exe filter_optional_proquota: Image|endswith: - :\Windows\System32\proquota.exe - :\Windows\SysWOW64\proquota.exe filter_optional_citrix: Image|endswith: - :\Program Files (x86)\Citrix\HDX\bin\cmstart.exe - :\Program Files (x86)\Citrix\HDX\bin\icast.exe - :\Program Files (x86)\Citrix\System32\icast.exe - :\Program Files\Citrix\HDX\bin\cmstart.exe - :\Program Files\Citrix\HDX\bin\icast.exe - :\Program Files\Citrix\System32\icast.exe filter_optional_image_null: Image: null condition: selection and not 1 of filter_main_* and not 1 of filter_optional_* falsepositives: - Legitimate logon scripts or custom shells may trigger false positives. Apply additional filters accordingly. level: high
Near-miss passage: Sigma rule: Detects suspicious child processes related to Windows Shell utilities spawned by `conhost.exe`, which could indicate mal. Logsource: windows / process_creation. Rule: title: Potentially Suspicious Child Processes Spawned by ConHost id: dfa03a09-8b92-4d83-8e74-f72839b1c407 related: - id: 7dc2dedd-7603-461a-bc13-15803d132355 type: similar status: experimental description: Detects suspicious child processes related to Windows Shell utilities spawned by `conhost.exe`, which could indicate malicious activity using trusted system components. references: - https://tria.ge/241015-l98snsyeje/behavioral2 author: Swachchhanda Shrawan Poudel (Nextron Systems) date: 2025-02-05 tags: - attack.stealth - attack.t1202 - attack.t1218 logsource: category: process_creation product: windows detection: selection_parent: ParentImage|endswith: \conhost.exe selection_child: - Image|endswith: - \cmd.exe - \cscript.exe - \mshta.exe - \powershell_ise.exe - \powershell.exe - \pwsh.exe - \regsvr32.exe - \wscript.exe - OriginalFileName: - cmd.exe - cscript.exe - mshta.exe - powershell_ise.exe - powershell.exe - pwsh.dll - regsvr32.exe - wscript.exe condition: all of selection_* falsepositives: - Legitimate administrative tasks using `conhost.exe` to spawn child processes such as `cmd.exe`, `powershell.exe`, or `regsvr32.exe`. level: high