Query: detection rule: Detects calls to base64 encoded WMI class such as "Win32_ShadowCopy", "Win32_ScheduledJob", etc.
Matching passage: Sigma rule: Detects calls to base64 encoded WMI class such as "Win32_ShadowCopy", "Win32_ScheduledJob", etc.. Logsource: windows / process_creation. Rule: title: PowerShell Base64 Encoded WMI Classes id: 1816994b-42e1-4fb1-afd2-134d88184f71 related: - id: 47688f1b-9f51-4656-b013-3cc49a166a36 type: obsolete status: test description: Detects calls to base64 encoded WMI class such as "Win32_ShadowCopy", "Win32_ScheduledJob", etc. references: - https://github.com/Neo23x0/Raccine/blob/20a569fa21625086433dcce8bb2765d0ea08dcb6/yara/mal_revil.yar author: Christian Burkard (Nextron Systems), Nasreddine Bencherchali (Nextron Systems) date: 2023-01-30 tags: - attack.execution - attack.stealth - attack.t1059.001 - attack.t1027 logsource: category: process_creation product: windows detection: selection_img: - Image|endswith: - \powershell.exe - \pwsh.exe - OriginalFileName: - PowerShell.EXE - pwsh.dll selection_cli_shadowcopy: CommandLine|contains: - VwBpAG4AMwAyAF8AUwBoAGEAZABvAHcAYwBvAHAAeQ - cAaQBuADMAMgBfAFMAaABhAGQAbwB3AGMAbwBwAHkA - XAGkAbgAzADIAXwBTAGgAYQBkAG8AdwBjAG8AcAB5A - V2luMzJfU2hhZG93Y29we - dpbjMyX1NoYWRvd2NvcH - XaW4zMl9TaGFkb3djb3B5 selection_cli_scheduledJob: CommandLine|contains: - VwBpAG4AMwAyAF8AUwBjAGgAZQBkAHUAbABlAGQASgBvAGIA - cAaQBuADMAMgBfAFMAYwBoAGUAZAB1AGwAZQBkAEoAbwBiA - XAGkAbgAzADIAXwBTAGMAaABlAGQAdQBsAGUAZABKAG8AYg - V2luMzJfU2NoZWR1bGVkSm9i - dpbjMyX1NjaGVkdWxlZEpvY - XaW4zMl9TY2hlZHVsZWRKb2 selection_cli_process: CommandLine|contains: - VwBpAG4AMwAyAF8AUAByAG8AYwBlAHMAcw - cAaQBuADMAMgBfAFAAcgBvAGMAZQBzAHMA - XAGkAbgAzADIAXwBQAHIAbwBjAGUAcwBzA - V2luMzJfUHJvY2Vzc - dpbjMyX1Byb2Nlc3 - XaW4zMl9Qcm9jZXNz selection_cli_useraccount: CommandLine|contains: - VwBpAG4AMwAyAF8AVQBzAGUAcgBBAGMAYwBvAHUAbgB0A - cAaQBuADMAMgBfAFUAcwBlAHIAQQBjAGMAbwB1AG4AdA - XAGkAbgAzADIAXwBVAHMAZQByAEEAYwBjAG8AdQBuAHQA - V2luMzJfVXNlckFjY291bn - dpbjMyX1VzZXJBY2NvdW50 - XaW4zMl9Vc2VyQWNjb3Vud selection_cli_loggedonuser: CommandLine|contains: - VwBpAG4AMwAyAF8ATABvAGcAZwBlAGQATwBuAFUAcwBlAHIA - cAaQBuADMAMgBfAEwAbwBnAGcAZQBkAE8AbgBVAHMAZQByA - XAGkAbgAzADIAXwBMAG8AZwBnAGUAZABPAG4AVQBzAGUAcg - V2luMzJfTG9nZ2VkT25Vc2Vy - dpbjMyX0xvZ2dlZE9uVXNlc - XaW4zMl9Mb2dnZWRPblVzZX condition: selection_img and 1 of selection_cli_* falsepositives: - Unknown level: high
Near-miss passage: Sigma rule: Detects uncommon or suspicious child processes spawning from a WSL process. This could indicate an attempt to evade pare. Logsource: windows / process_creation. Rule: title: WSL Child Process Anomaly id: 2267fe65-0681-42ad-9a6d-46553d3f3480 related: - id: dec44ca7-61ad-493c-bfd7-8819c5faa09b type: derived status: test description: Detects uncommon or suspicious child processes spawning from a WSL process. This could indicate an attempt to evade parent/child relationship detections or persistence attempts via cron using WSL references: - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Wsl/ - https://twitter.com/nas_bench/status/1535431474429808642 author: Nasreddine Bencherchali (Nextron Systems) date: 2023-01-23 modified: 2023-08-15 tags: - attack.execution - attack.stealth - attack.t1218 - attack.t1202 logsource: category: process_creation product: windows detection: selection_parent: ParentImage|endswith: - \wsl.exe - \wslhost.exe selection_children_images: Image|endswith: - \calc.exe - \cmd.exe - \cscript.exe - \mshta.exe - \powershell.exe - \pwsh.exe - \regsvr32.exe - \rundll32.exe - \wscript.exe selection_children_paths: Image|contains: - \AppData\Local\Temp\ - C:\Users\Public\ - C:\Windows\Temp\ - C:\Temp\ - \Downloads\ - \Desktop\ condition: selection_parent and 1 of selection_children_* falsepositives: - Unknown level: medium