{"id":"9f50fe98-fe5c-4a2d-86c7-fad7f63ed622","title":"Potentially Suspicious ASP.NET Compilation Via AspNetCompiler","description":"Detects execution of \"aspnet_compiler.exe\" with potentially suspicious paths for compilation.","author":"Nasreddine Bencherchali (Nextron Systems)","status":"test","level":"high","date":"2023-08-14","modified":"2025-02-24","tags":["attack.execution","attack.stealth","attack.t1127"],"technique_ids":["T1127"],"logsource":{"category":"process_creation","product":"windows"},"falsepositives":["Unknown"],"references":["https://lolbas-project.github.io/lolbas/Binaries/Aspnet_Compiler/","https://ijustwannared.team/2020/08/01/the-curious-case-of-aspnet_compiler-exe/"],"source_path":"rules/windows/process_creation/proc_creation_win_aspnet_compiler_susp_paths.yml","source_sha256":"130b30e44af117be791ee00893a9878c3b3a59c9e07bfa113137de6ad0e0b2bd","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/process_creation/proc_creation_win_aspnet_compiler_susp_paths.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: Potentially Suspicious ASP.NET Compilation Via AspNetCompiler\nid: 9f50fe98-fe5c-4a2d-86c7-fad7f63ed622 # Susp Paths\nrelated:\n    - id: 9ccba514-7cb6-4c5c-b377-700758f2f120 # SuspChild\n      type: similar\n    - id: 4c7f49ee-2638-43bb-b85b-ce676c30b260 # TMP File\n      type: similar\n    - id: a01b8329-5953-4f73-ae2d-aa01e1f35f00 # Exec\n      type: similar\nstatus: test\ndescription: Detects execution of \"aspnet_compiler.exe\" with potentially suspicious paths for compilation.\nreferences:\n    - https://lolbas-project.github.io/lolbas/Binaries/Aspnet_Compiler/\n    - https://ijustwannared.team/2020/08/01/the-curious-case-of-aspnet_compiler-exe/\nauthor: Nasreddine Bencherchali (Nextron Systems)\ndate: 2023-08-14\nmodified: 2025-02-24\ntags:\n    - attack.execution\n    - attack.stealth\n    - attack.t1127\nlogsource:\n    category: process_creation\n    product: windows\ndetection:\n    selection:\n        Image|contains:\n            - ':\\Windows\\Microsoft.NET\\Framework\\'\n            - ':\\Windows\\Microsoft.NET\\Framework64\\'\n            - ':\\Windows\\Microsoft.NET\\FrameworkArm\\'\n            - ':\\Windows\\Microsoft.NET\\FrameworkArm64\\'\n        Image|endswith: '\\aspnet_compiler.exe'\n        CommandLine|contains:\n            # Note: add other potential suspicious paths\n            - '\\Users\\Public\\'\n            - '\\AppData\\Local\\Temp\\'\n            - '\\AppData\\Local\\Roaming\\'\n            - ':\\Temp\\'\n            - ':\\Windows\\Temp\\'\n            - ':\\Windows\\System32\\Tasks\\'\n            - ':\\Windows\\Tasks\\'\n    condition: selection\nfalsepositives:\n    - Unknown\nlevel: high\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1127","id":"T1127","name":"Trusted Developer Utilities Proxy Execution","page":"techniques/enterprise/T1127/"}],"data_path":"data/detection-rules/9f50fe98-fe5c-4a2d-86c7-fad7f63ed622.json","kind":"sigma"}