Query: rule covering Detects the execution of obfuscated PowerShell commands that attempt to install MSI packages via the Windows Installer C
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 execition of commands and binaries from the context of The program compatibility assistant (Pcalua.exe). This ca. Logsource: windows / process_creation. Rule: title: Use of Pcalua For Execution id: 0955e4e1-c281-4fb9-9ee1-5ee7b4b754d2 related: - id: fa47597e-90e9-41cd-ab72-c3b74cfb0d02 type: obsolete status: test description: Detects execition of commands and binaries from the context of The program compatibility assistant (Pcalua.exe). This can be used as a LOLBIN in order to bypass application whitelisting. references: - https://lolbas-project.github.io/lolbas/Binaries/Pcalua/ - https://pentestlab.blog/2020/07/06/indirect-command-execution/ author: Nasreddine Bencherchali (Nextron Systems), E.M. Anhaus (originally from Atomic Blue Detections, Endgame), oscd.community date: 2022-06-14 modified: 2023-01-04 tags: - attack.execution - attack.t1059 logsource: category: process_creation product: windows detection: selection: Image|endswith: \pcalua.exe CommandLine|contains: ' -a' condition: selection falsepositives: - Legitimate use by a via a batch script or by an administrator. level: medium