{"id":"3f3f3506-1895-401b-9cc3-e86b16e630d0","title":"Potential Direct Syscall of NtOpenProcess","description":"Detects potential calls to NtOpenProcess directly from NTDLL.","author":"Christian Burkard (Nextron Systems), Tim Shelton (FP)","status":"test","level":"medium","date":"2021-07-28","modified":"2023-12-13","tags":["attack.execution","attack.t1106"],"technique_ids":["T1106"],"logsource":{"category":"process_access","product":"windows"},"falsepositives":["Unknown"],"references":["https://medium.com/falconforce/falconfriday-direct-system-calls-and-cobalt-strike-bofs-0xff14-741fa8e1bdd6"],"source_path":"rules/windows/process_access/proc_access_win_susp_direct_ntopenprocess_call.yml","source_sha256":"1b735d42840bb6c1fbcf7bb506675babe9ba14329728131848e6bfe671f05675","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/process_access/proc_access_win_susp_direct_ntopenprocess_call.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: Potential Direct Syscall of NtOpenProcess\nid: 3f3f3506-1895-401b-9cc3-e86b16e630d0\nstatus: test\ndescription: Detects potential calls to NtOpenProcess directly from NTDLL.\nreferences:\n    - https://medium.com/falconforce/falconfriday-direct-system-calls-and-cobalt-strike-bofs-0xff14-741fa8e1bdd6\nauthor: Christian Burkard (Nextron Systems), Tim Shelton (FP)\ndate: 2021-07-28\nmodified: 2023-12-13\ntags:\n    - attack.execution\n    - attack.t1106\nlogsource:\n    category: process_access\n    product: windows\ndetection:\n    selection:\n        CallTrace|startswith: 'UNKNOWN'\n    filter_main_vcredist:\n        TargetImage|endswith: 'vcredist_x64.exe'\n        SourceImage|endswith: 'vcredist_x64.exe'\n    filter_main_generic:\n        # Examples include \"systeminfo\", \"backgroundTaskHost\", \"AUDIODG\"\n        SourceImage|contains:\n            - ':\\Program Files (x86)\\'\n            - ':\\Program Files\\'\n            - ':\\Windows\\System32\\'\n            - ':\\Windows\\SysWOW64\\'\n            - ':\\Windows\\WinSxS\\'\n        TargetImage|contains:\n            - ':\\Program Files (x86)\\'\n            - ':\\Program Files\\'\n            - ':\\Windows\\System32\\'\n            - ':\\Windows\\SysWOW64\\'\n            - ':\\Windows\\WinSxS\\'\n    filter_main_kerneltrace_edge:\n        # Cases in which the CallTrace is just e.g. 'UNKNOWN(19290435374)' from Microsoft-Windows-Kernel-Audit-API-Calls provider\n        Provider_Name: 'Microsoft-Windows-Kernel-Audit-API-Calls'\n    filter_optional_vmware:\n        TargetImage|endswith: ':\\Windows\\system32\\systeminfo.exe'\n        SourceImage|endswith: 'setup64.exe' # vmware\n    filter_optional_cylance:\n        SourceImage|endswith: ':\\Windows\\Explorer.EXE'\n        TargetImage|endswith: ':\\Program Files\\Cylance\\Desktop\\CylanceUI.exe'\n    filter_optional_amazon:\n        SourceImage|endswith: 'AmazonSSMAgentSetup.exe'\n        TargetImage|endswith: 'AmazonSSMAgentSetup.exe'\n    filter_optional_vscode: # VsCode\n        SourceImage|endswith: '\\AppData\\Local\\Programs\\Microsoft VS Code\\Code.exe'\n        TargetImage|endswith: '\\AppData\\Local\\Programs\\Microsoft VS Code\\Code.exe'\n    filter_optional_teams: # MS Teams\n        TargetImage|endswith: '\\AppData\\Local\\Microsoft\\Teams\\current\\Teams.exe'\n        SourceImage|endswith: '\\AppData\\Local\\Microsoft\\Teams\\current\\Teams.exe'\n    filter_optional_discord: # Discord\n        TargetImage|contains: '\\AppData\\Local\\Discord\\'\n        TargetImage|endswith: '\\Discord.exe'\n    filter_optional_yammer:\n        SourceImage|contains: '\\AppData\\Local\\yammerdesktop\\app-'\n        SourceImage|endswith: '\\Yammer.exe'\n        TargetImage|contains: '\\AppData\\Local\\yammerdesktop\\app-'\n        TargetImage|endswith: '\\Yammer.exe'\n        GrantedAccess: '0x1000'\n    filter_optional_evernote:\n        TargetImage|endswith: '\\Evernote\\Evernote.exe'\n    filter_optional_adobe_acrobat:\n        SourceImage|contains: ':\\Program Files\\Adobe\\Acrobat DC\\Acrobat\\'\n        SourceImage|endswith: '\\AcroCEF.exe'\n        TargetImage|contains: ':\\Program Files\\Adobe\\Acrobat DC\\Acrobat\\'\n        TargetImage|endswith: '\\AcroCEF.exe'\n    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*\nfalsepositives:\n    - Unknown\nlevel: medium\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1106","id":"T1106","name":"Native API","page":"techniques/enterprise/T1106/"}],"data_path":"data/detection-rules/3f3f3506-1895-401b-9cc3-e86b16e630d0.json","kind":"sigma"}