{"id":"9c0295ce-d60d-40bd-bd74-84673b7592b1","title":"Suspicious Encoded And Obfuscated Reflection Assembly Load Function Call","description":"Detects suspicious base64 encoded and obfuscated \"LOAD\" keyword used in .NET \"reflection.assembly\"","author":"pH-T (Nextron Systems)","status":"test","level":"high","date":"2022-03-01","modified":"2023-04-06","tags":["attack.execution","attack.stealth","attack.t1059.001","attack.t1027"],"technique_ids":["T1027","T1059.001"],"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/","https://learn.microsoft.com/en-us/dotnet/api/system.appdomain.load?view=net-7.0"],"source_path":"rules/windows/process_creation/proc_creation_win_powershell_base64_reflection_assembly_load_obfusc.yml","source_sha256":"97df99302b8e26966b8279faebd996bd3937188d81ddda19e4ed68929ebf3fab","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/process_creation/proc_creation_win_powershell_base64_reflection_assembly_load_obfusc.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: Suspicious Encoded And Obfuscated Reflection Assembly Load Function Call\nid: 9c0295ce-d60d-40bd-bd74-84673b7592b1\nrelated:\n    - id: 62b7ccc9-23b4-471e-aa15-6da3663c4d59\n      type: similar\nstatus: test\ndescription: Detects suspicious base64 encoded and obfuscated \"LOAD\" keyword used in .NET \"reflection.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/\n    - https://learn.microsoft.com/en-us/dotnet/api/system.appdomain.load?view=net-7.0\nauthor: pH-T (Nextron Systems)\ndate: 2022-03-01\nmodified: 2023-04-06\ntags:\n    - attack.execution\n    - attack.stealth\n    - attack.t1059.001\n    - attack.t1027\nlogsource:\n    category: process_creation\n    product: windows\ndetection:\n    selection:\n        CommandLine|contains:\n            # ::(\"L\"+\"oad\")\n            - 'OgA6ACgAIgBMACIAKwAiAG8AYQBkACIAKQ'\n            - 'oAOgAoACIATAAiACsAIgBvAGEAZAAiACkA'\n            - '6ADoAKAAiAEwAIgArACIAbwBhAGQAIgApA'\n            # ::(\"Lo\"+\"ad\")\n            - 'OgA6ACgAIgBMAG8AIgArACIAYQBkACIAKQ'\n            - 'oAOgAoACIATABvACIAKwAiAGEAZAAiACkA'\n            - '6ADoAKAAiAEwAbwAiACsAIgBhAGQAIgApA'\n            # ::(\"Loa\"+\"d\")\n            - 'OgA6ACgAIgBMAG8AYQAiACsAIgBkACIAKQ'\n            - 'oAOgAoACIATABvAGEAIgArACIAZAAiACkA'\n            - '6ADoAKAAiAEwAbwBhACIAKwAiAGQAIgApA'\n            # ::('L'+'oad')\n            - 'OgA6ACgAJwBMACcAKwAnAG8AYQBkACcAKQ'\n            - 'oAOgAoACcATAAnACsAJwBvAGEAZAAnACkA'\n            - '6ADoAKAAnAEwAJwArACcAbwBhAGQAJwApA'\n            # ::('Lo'+'ad')\n            - 'OgA6ACgAJwBMAG8AJwArACcAYQBkACcAKQ'\n            - 'oAOgAoACcATABvACcAKwAnAGEAZAAnACkA'\n            - '6ADoAKAAnAEwAbwAnACsAJwBhAGQAJwApA'\n            # ::('Loa'+'d')\n            - 'OgA6ACgAJwBMAG8AYQAnACsAJwBkACcAKQ'\n            - 'oAOgAoACcATABvAGEAJwArACcAZAAnACkA'\n            - '6ADoAKAAnAEwAbwBhACcAKwAnAGQAJwApA'\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/"}],"data_path":"data/detection-rules/9c0295ce-d60d-40bd-bd74-84673b7592b1.json","kind":"sigma"}