{"id":"62b7ccc9-23b4-471e-aa15-6da3663c4d59","title":"PowerShell Base64 Encoded Reflective Assembly Load","description":"Detects base64 encoded .NET reflective loading of Assembly","author":"Christian Burkard (Nextron Systems), pH-T (Nextron Systems)","status":"test","level":"high","date":"2022-03-01","modified":"2023-01-30","tags":["attack.execution","attack.stealth","attack.t1059.001","attack.t1027","attack.t1620"],"technique_ids":["T1027","T1059.001","T1620"],"logsource":{"category":"process_creation","product":"windows"},"falsepositives":["Unlikely"],"references":["https://github.com/Neo23x0/Raccine/blob/20a569fa21625086433dcce8bb2765d0ea08dcb6/yara/mal_revil.yar","https://thedfirreport.com/2022/05/09/seo-poisoning-a-gootloader-story/"],"source_path":"rules/windows/process_creation/proc_creation_win_powershell_base64_reflection_assembly_load.yml","source_sha256":"e21ad44fa75e14737ee876428435d8fe5f2be5eeba12219ecef79baa54ea1756","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/process_creation/proc_creation_win_powershell_base64_reflection_assembly_load.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: PowerShell Base64 Encoded Reflective Assembly Load\nid: 62b7ccc9-23b4-471e-aa15-6da3663c4d59\nrelated:\n    - id: 9c0295ce-d60d-40bd-bd74-84673b7592b1\n      type: similar\nstatus: test\ndescription: Detects base64 encoded .NET reflective loading of Assembly\nreferences:\n    - https://github.com/Neo23x0/Raccine/blob/20a569fa21625086433dcce8bb2765d0ea08dcb6/yara/mal_revil.yar\n    - https://thedfirreport.com/2022/05/09/seo-poisoning-a-gootloader-story/\nauthor: Christian Burkard (Nextron Systems), pH-T (Nextron Systems)\ndate: 2022-03-01\nmodified: 2023-01-30\ntags:\n    - attack.execution\n    - attack.stealth\n    - attack.t1059.001\n    - attack.t1027\n    - attack.t1620\nlogsource:\n    category: process_creation\n    product: windows\ndetection:\n    selection:\n        CommandLine|contains:\n            # [Reflection.Assembly]::Load(\n            - 'WwBSAGUAZgBsAGUAYwB0AGkAbwBuAC4AQQBzAHMAZQBtAGIAbAB5AF0AOgA6AEwAbwBhAGQAKA'\n            - 'sAUgBlAGYAbABlAGMAdABpAG8AbgAuAEEAcwBzAGUAbQBiAGwAeQBdADoAOgBMAG8AYQBkACgA'\n            - 'bAFIAZQBmAGwAZQBjAHQAaQBvAG4ALgBBAHMAcwBlAG0AYgBsAHkAXQA6ADoATABvAGEAZAAoA'\n            # [reflection.assembly]::(\"Load\")\n            - 'AFsAcgBlAGYAbABlAGMAdABpAG8AbgAuAGEAcwBzAGUAbQBiAGwAeQBdADoAOgAoACIATABvAGEAZAAiAC'\n            - 'BbAHIAZQBmAGwAZQBjAHQAaQBvAG4ALgBhAHMAcwBlAG0AYgBsAHkAXQA6ADoAKAAiAEwAbwBhAGQAIgAp'\n            - 'AWwByAGUAZgBsAGUAYwB0AGkAbwBuAC4AYQBzAHMAZQBtAGIAbAB5AF0AOgA6ACgAIgBMAG8AYQBkACIAK'\n            # [Reflection.Assembly]::(\"Load\")\n            - 'WwBSAGUAZgBsAGUAYwB0AGkAbwBuAC4AQQBzAHMAZQBtAGIAbAB5AF0AOgA6ACgAIgBMAG8AYQBkACIAKQ'\n            - 'sAUgBlAGYAbABlAGMAdABpAG8AbgAuAEEAcwBzAGUAbQBiAGwAeQBdADoAOgAoACIATABvAGEAZAAiACkA'\n            - 'bAFIAZQBmAGwAZQBjAHQAaQBvAG4ALgBBAHMAcwBlAG0AYgBsAHkAXQA6ADoAKAAiAEwAbwBhAGQAIgApA'\n            # [reflection.assembly]::Load(\n            - 'WwByAGUAZgBsAGUAYwB0AGkAbwBuAC4AYQBzAHMAZQBtAGIAbAB5AF0AOgA6AEwAbwBhAGQAKA'\n            - 'sAcgBlAGYAbABlAGMAdABpAG8AbgAuAGEAcwBzAGUAbQBiAGwAeQBdADoAOgBMAG8AYQBkACgA'\n            - 'bAHIAZQBmAGwAZQBjAHQAaQBvAG4ALgBhAHMAcwBlAG0AYgBsAHkAXQA6ADoATABvAGEAZAAoA'\n    condition: selection\nfalsepositives:\n    - Unlikely\nlevel: high\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1027","id":"T1027","name":"Obfuscated Files or Information","page":"techniques/enterprise/T1027/"},{"key":"enterprise/T1059.001","id":"T1059.001","name":"PowerShell","page":"techniques/enterprise/T1059.001/"},{"key":"enterprise/T1620","id":"T1620","name":"Reflective Code Loading","page":"techniques/enterprise/T1620/"}],"data_path":"data/detection-rules/62b7ccc9-23b4-471e-aa15-6da3663c4d59.json","kind":"sigma"}