Query: Sigma YAML for windows / process_creation
Matching passage: Sigma rule: Detects suspicious UTF16 and base64 encoded and often obfuscated PowerShell code often used in command lines. Logsource: windows / process_creation. Rule: title: Suspicious Obfuscated PowerShell Code id: 8d01b53f-456f-48ee-90f6-bc28e67d4e35 status: test description: Detects suspicious UTF16 and base64 encoded and often obfuscated PowerShell code often used in command lines references: - https://app.any.run/tasks/fcadca91-3580-4ede-aff4-4d2bf809bf99/ author: Florian Roth (Nextron Systems) date: 2022-07-11 modified: 2023-02-14 tags: - attack.stealth logsource: category: process_creation product: windows detection: selection: CommandLine|contains: - IAAtAGIAeABvAHIAIAAwAHgA - AALQBiAHgAbwByACAAMAB4A - gAC0AYgB4AG8AcgAgADAAeA - AC4ASQBuAHYAbwBrAGUAKAApACAAfAAg - AuAEkAbgB2AG8AawBlACgAKQAgAHwAI - ALgBJAG4AdgBvAGsAZQAoACkAIAB8AC - AHsAMQB9AHsAMAB9ACIAIAAtAGYAI - B7ADEAfQB7ADAAfQAiACAALQBmAC - AewAxAH0AewAwAH0AIgAgAC0AZgAg - AHsAMAB9AHsAMwB9ACIAIAAtAGYAI - B7ADAAfQB7ADMAfQAiACAALQBmAC - AewAwAH0AewAzAH0AIgAgAC0AZgAg - AHsAMgB9AHsAMAB9ACIAIAAtAGYAI - B7ADIAfQB7ADAAfQAiACAALQBmAC - AewAyAH0AewAwAH0AIgAgAC0AZgAg - AHsAMQB9AHsAMAB9ACcAIAAtAGYAI - B7ADEAfQB7ADAAfQAnACAALQBmAC - AewAxAH0AewAwAH0AJwAgAC0AZgAg - AHsAMAB9AHsAMwB9ACcAIAAtAGYAI - B7ADAAfQB7ADMAfQAnACAALQBmAC - AewAwAH0AewAzAH0AJwAgAC0AZgAg - AHsAMgB9AHsAMAB9ACcAIAAtAGYAI - B7ADIAfQB7ADAAfQAnACAALQBmAC - AewAyAH0AewAwAH0AJwAgAC0AZgAg condition: selection falsepositives: - Unknown level: high
Near-miss passage: Sigma rule: Detects the installation of MSIX/AppX packages with full trust privileges which run with elevated privileges outside nor. Logsource: windows / appxdeployment-server. Rule: title: Windows AppX Deployment Full Trust Package Installation id: e54279c7-4910-4e2c-902c-c56a25b549f6 status: experimental description: Detects the installation of MSIX/AppX packages with full trust privileges which run with elevated privileges outside normal AppX container restrictions references: - https://www.splunk.com/en_us/blog/security/msix-weaponization-threat-detection-splunk.html author: Michael Haag, Swachchhanda Shrawan Poudel (Nextron Systems) date: 2025-11-03 tags: - attack.execution - attack.defense-impairment - attack.t1204.002 - attack.t1553.005 logsource: product: windows service: appxdeployment-server detection: selection: EventID: 400 HasFullTrust: true filter_main_legitpath: PackageSourceUri|startswith: - file:///C:/Program%20Files/ - file:///C:/Program%20Files%20(x86)/ filter_main_microsoft: - PackageSourceUri|startswith: https://go.microsoft.com/fwlink/?linkid - PackageSourceUri|contains: - .cdn.microsoft.com - .cdn.office.net/ filter_main_callerprocess: CallingProcess|startswith: - sysprep.exe - svchost.exe,AppReadiness filter_optional_x_update: PackageSourceUri|startswith: x-windowsupdate:// filter_optional_microsoftclient: PackageFullName|startswith: MicrosoftWindows.Client. condition: selection and not 1 of filter_main_* and not 1 of filter_optional_* falsepositives: - Some legitimate applications installation which have been missed from filtering can generate fps, thus baselining and tuning is recommended before deploying to production level: medium