Query: Sigma YAML for windows / process_creation
Matching passage: Sigma rule: Detects the execution of obfuscated PowerShell commands that attempt to install MSI packages via the Windows Installer C. Logsource: windows / process_creation. Rule: title: Obfuscated PowerShell MSI Install via WindowsInstaller COM id: 7b6a7418-3afc-11f0-aff4-000d3abf478c status: experimental description: 'Detects the execution of obfuscated PowerShell commands that attempt to install MSI packages via the Windows Installer COM object (`WindowsInstaller.Installer`). The technique involves manipulating strings to hide functionality, such as constructing class names using string insertion (e.g., ''indowsInstaller.Installer''.Insert(0,''W'')) and correcting malformed URLs (e.g., converting ''htps://'' to ''https://'') at runtime. This behavior is commonly associated with malware loaders or droppers that aim to bypass static detection by hiding intent in runtime-generated strings and using legitimate tools for code execution. The use of `InstallProduct` and COM object creation, particularly combined with hidden window execution and suppressed UI, indicates an attempt to install software (likely malicious) without user interaction. ' references: - https://informationsecuritybuzz.com/the-real-danger-behind-a-simple-windows-shortcut/ - https://redcanary.com/blog/threat-intelligence/intelligence-insights-may-2025/ - https://www.virustotal.com/gui/file/f9710b0ba4de5fa0e7ec27da462d4d2fc6838eba83a19f23f6617a466bbad457 author: Meroujan Antonyan (vx3r) date: 2025-05-27 tags: - attack.stealth - attack.t1027.010 - attack.t1218.007 - attack.execution - attack.t1059.001 logsource: category: process_creation product: windows detection: selection_img: - Image|endswith: - \powershell_ise.exe - \powershell.exe - \pwsh.exe - OriginalFileName: - PowerShell_ISE.EXE - PowerShell.EXE - pwsh.dll selection_cli: CommandLine|contains|all: - -ComObject - InstallProduct( - .Insert( - UILevel condition: all of selection_* falsepositives: - Unknown level: high
Near-miss passage: Sigma rule: Detects suspicious child processes of "provlaunch.exe" which might indicate potential abuse to proxy execution.. Logsource: windows / process_creation. Rule: title: Suspicious Provlaunch.EXE Child Process id: f9999590-1f94-4a34-a91e-951e47bedefd related: - id: 7f5d1c9a-3e83-48df-95a7-2b98aae6c13c type: similar - id: 2a4b3e61-9d22-4e4a-b60f-6e8f0cde6f25 type: similar - id: 7021255e-5db3-4946-a8b9-0ba7a4644a69 type: similar status: test description: Detects suspicious child processes of "provlaunch.exe" which might indicate potential abuse to proxy execution. references: - https://lolbas-project.github.io/lolbas/Binaries/Provlaunch/ - https://twitter.com/0gtweet/status/1674399582162153472 author: Nasreddine Bencherchali (Nextron Systems) date: 2023-08-08 tags: - attack.stealth - attack.t1218 logsource: category: process_creation product: windows detection: selection_parent: ParentImage|endswith: \provlaunch.exe selection_child: - Image|endswith: - \calc.exe - \cmd.exe - \cscript.exe - \mshta.exe - \notepad.exe - \powershell.exe - \pwsh.exe - \regsvr32.exe - \rundll32.exe - \wscript.exe - Image|contains: - :\PerfLogs\ - :\Temp\ - :\Users\Public\ - \AppData\Temp\ - \Windows\System32\Tasks\ - \Windows\Tasks\ - \Windows\Temp\ condition: all of selection_* falsepositives: - Unknown level: high