Query: rule covering Detects suspicious powershell process starts with base64 encoded commands (e.g. Emotet)
Matching passage: Sigma rule: Detects suspicious powershell process starts with base64 encoded commands (e.g. Emotet). Logsource: windows / process_creation. Rule: title: Suspicious Encoded PowerShell Command Line id: ca2092a1-c273-4878-9b4b-0d60115bf5ea status: test description: Detects suspicious powershell process starts with base64 encoded commands (e.g. Emotet) references: - https://app.any.run/tasks/6217d77d-3189-4db2-a957-8ab239f3e01e author: Florian Roth (Nextron Systems), Markus Neis, Jonhnathan Ribeiro, Daniil Yugoslavskiy, Anton Kutepov, oscd.community date: 2018-09-03 modified: 2023-04-06 tags: - attack.execution - attack.t1059.001 logsource: category: process_creation product: windows detection: selection_img: - Image|endswith: - \powershell.exe - \pwsh.exe - OriginalFileName: - PowerShell.EXE - pwsh.dll selection_cli_enc: CommandLine|contains: ' -e' selection_cli_content: CommandLine|contains: - ' JAB' - ' SUVYI' - ' SQBFAFgA' - ' aQBlAHgA' - ' aWV4I' - ' IAA' - ' IAB' - ' UwB' - ' cwB' selection_standalone: CommandLine|contains: - '.exe -ENCOD ' - ' BA^J e-' filter_optional_remote_signed: CommandLine|contains: ' -ExecutionPolicy remotesigned ' condition: selection_img and (all of selection_cli_* or selection_standalone) and not 1 of filter_optional_* level: high
Near-miss passage: Sigma rule: Detects Windows executables that write files with suspicious extensions. Logsource: windows / file_event. Rule: title: Windows Binaries Write Suspicious Extensions id: b8fd0e93-ff58-4cbd-8f48-1c114e342e62 related: - id: 1277f594-a7d1-4f28-a2d3-73af5cbeab43 type: derived status: test description: Detects Windows executables that write files with suspicious extensions references: - Internal Research author: Nasreddine Bencherchali (Nextron Systems) date: 2022-08-12 modified: 2025-10-07 tags: - attack.stealth - attack.t1036 logsource: category: file_event product: windows detection: selection_generic: Image|endswith: - \csrss.exe - \lsass.exe - \RuntimeBroker.exe - \sihost.exe - \smss.exe - \wininit.exe - \winlogon.exe TargetFilename|endswith: - .bat - .dll - .exe - .hta - .iso - .ps1 - .txt - .vbe - .vbs selection_special: Image|endswith: - \dllhost.exe - \rundll32.exe - \svchost.exe TargetFilename|endswith: - .bat - .hta - .iso - .ps1 - .vbe - .vbs filter_main_AppLockerPolicyTest: Image: C:\Windows\System32\dllhost.exe TargetFilename|contains|all: - :\Users\ - \AppData\Local\Temp\__PSScriptPolicyTest_ TargetFilename|endswith: .ps1 filter_main_script_gpo_machine: Image: C:\Windows\system32\svchost.exe TargetFilename|contains|all: - C:\Windows\System32\GroupPolicy\DataStore\ - \sysvol\ - \Policies\ - \Machine\Scripts\Startup\ TargetFilename|endswith: - .ps1 - .bat filter_main_clipchamp: Image: C:\Windows\system32\svchost.exe TargetFilename|contains|all: - C:\Program Files\WindowsApps\Clipchamp - .ps1 filter_main_powershell_preview: Image: - C:\Windows\system32\svchost.exe - C:\Windows\SysWOW64\svchost.exe TargetFilename|startswith: - C:\Program Files\WindowsApps\Microsoft.PowerShellPreview - C:\Program Files (x86)\WindowsApps\Microsoft.PowerShellPreview TargetFilename|endswith: .ps1 condition: 1 of selection_* and not 1 of filter_main_* falsepositives: - Unknown level: high