{"id":"40b95d31-1afc-469e-8d34-9a3a667d058e","title":"Suspicious Csi.exe Usage","description":"Csi.exe is a signed binary from Microsoft that comes with Visual Studio and provides C# interactive capabilities. It can be used to run C# code from a file passed as a parameter in command line. Early version of this utility provided with Microsoft “Roslyn” Community Technology Preview was named 'rcsi.exe'","author":"Konstantin Grishchenko, oscd.community","status":"test","level":"medium","date":"2020-10-17","modified":"2022-07-11","tags":["attack.lateral-movement","attack.execution","attack.stealth","attack.t1072","attack.t1218"],"technique_ids":["T1072","T1218"],"logsource":{"category":"process_creation","product":"windows"},"falsepositives":["Legitimate usage by software developers"],"references":["https://lolbas-project.github.io/lolbas/OtherMSBinaries/Csi/","https://lolbas-project.github.io/lolbas/OtherMSBinaries/Rcsi/","https://enigma0x3.net/2016/11/21/bypassing-application-whitelisting-by-using-rcsi-exe/","https://twitter.com/Z3Jpa29z/status/1317545798981324801"],"source_path":"rules/windows/process_creation/proc_creation_win_csi_execution.yml","source_sha256":"0836505a9dc5c390e21a2f2005bdaec06d5c755659274b171394280621be5ab8","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/process_creation/proc_creation_win_csi_execution.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 Csi.exe Usage\nid: 40b95d31-1afc-469e-8d34-9a3a667d058e\nstatus: test\ndescription: Csi.exe is a signed binary from Microsoft that comes with Visual Studio and provides C# interactive capabilities. It can be used to run C# code from a file passed as a parameter in command line. Early version of this utility provided with Microsoft “Roslyn” Community Technology Preview was named 'rcsi.exe'\nreferences:\n    - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Csi/\n    - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Rcsi/\n    - https://enigma0x3.net/2016/11/21/bypassing-application-whitelisting-by-using-rcsi-exe/\n    - https://twitter.com/Z3Jpa29z/status/1317545798981324801\nauthor: Konstantin Grishchenko, oscd.community\ndate: 2020-10-17\nmodified: 2022-07-11\ntags:\n    - attack.lateral-movement\n    - attack.execution\n    - attack.stealth\n    - attack.t1072\n    - attack.t1218\nlogsource:\n    category: process_creation\n    product: windows\ndetection:\n    selection_img:\n        - Image|endswith:\n              - '\\csi.exe'\n              - '\\rcsi.exe'\n        - OriginalFileName:\n              - 'csi.exe'\n              - 'rcsi.exe'\n    selection_cli:\n        Company: 'Microsoft Corporation'\n    condition: all of selection*\nfalsepositives:\n    - Legitimate usage by software developers\nlevel: medium\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1072","id":"T1072","name":"Software Deployment Tools","page":"techniques/enterprise/T1072/"},{"key":"enterprise/T1218","id":"T1218","name":"System Binary Proxy Execution","page":"techniques/enterprise/T1218/"}],"data_path":"data/detection-rules/40b95d31-1afc-469e-8d34-9a3a667d058e.json","kind":"sigma"}