{"id":"9ae01559-cf7e-4f8e-8e14-4c290a1b4784","title":"CredUI.DLL Loaded By Uncommon Process","description":"Detects loading of \"credui.dll\" and related DLLs by an uncommon process. Attackers might leverage this DLL for potential use of \"CredUIPromptForCredentials\" or \"CredUnPackAuthenticationBufferW\".","author":"Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)","status":"test","level":"medium","date":"2020-10-20","modified":"2025-12-09","tags":["attack.credential-access","attack.collection","attack.t1056.002"],"technique_ids":["T1056.002"],"logsource":{"category":"image_load","product":"windows"},"falsepositives":["Other legitimate processes loading those DLLs in your environment."],"references":["https://securitydatasets.com/notebooks/atomic/windows/credential_access/SDWIN-201020013208.html","https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1056.002/T1056.002.md#atomic-test-2---powershell---prompt-user-for-password","https://learn.microsoft.com/en-us/windows/win32/api/wincred/nf-wincred-creduipromptforcredentialsa","https://github.com/S12cybersecurity/RDPCredentialStealer"],"source_path":"rules/windows/image_load/image_load_dll_credui_uncommon_process_load.yml","source_sha256":"703b6bbf227e8e702df2c134c9f5c48dc66ebfc40dce9dd835a6d5db5160623f","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/image_load/image_load_dll_credui_uncommon_process_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: CredUI.DLL Loaded By Uncommon Process\nid: 9ae01559-cf7e-4f8e-8e14-4c290a1b4784\nstatus: test\ndescription: Detects loading of \"credui.dll\" and related DLLs by an uncommon process. Attackers might leverage this DLL for potential use of \"CredUIPromptForCredentials\" or \"CredUnPackAuthenticationBufferW\".\nreferences:\n    - https://securitydatasets.com/notebooks/atomic/windows/credential_access/SDWIN-201020013208.html\n    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1056.002/T1056.002.md#atomic-test-2---powershell---prompt-user-for-password\n    - https://learn.microsoft.com/en-us/windows/win32/api/wincred/nf-wincred-creduipromptforcredentialsa\n    - https://github.com/S12cybersecurity/RDPCredentialStealer\nauthor: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)\ndate: 2020-10-20\nmodified: 2025-12-09\ntags:\n    - attack.credential-access\n    - attack.collection\n    - attack.t1056.002\nlogsource:\n    category: image_load\n    product: windows\ndetection:\n    selection:\n        - ImageLoaded|endswith:\n              - '\\credui.dll'\n              - '\\wincredui.dll'\n        - OriginalFileName:\n              - 'credui.dll'\n              - 'wincredui.dll'\n    filter_main_generic:\n        Image|startswith:\n            - 'C:\\Program Files (x86)\\'\n            - 'C:\\Program Files\\'\n            - 'C:\\Windows\\System32\\'\n            - 'C:\\Windows\\SysWOW64\\'\n            - 'C:\\Windows\\SystemApps\\'\n    filter_main_full:\n        Image:\n            - 'C:\\Windows\\explorer.exe'\n            - 'C:\\Windows\\ImmersiveControlPanel\\SystemSettings.exe'\n            - 'C:\\Windows\\regedit.exe' # This FP is triggered for example when choosing the \"Connect Network Registry\" from the menu\n    filter_optional_opera:\n        Image|endswith: '\\opera_autoupdate.exe'\n    filter_optional_process_explorer:\n        Image|endswith:\n            - '\\procexp64.exe'\n            - '\\procexp.exe'\n    filter_optional_teams:\n        Image|startswith: 'C:\\Users\\'\n        Image|contains: '\\AppData\\Local\\Microsoft\\Teams\\'\n        Image|endswith: '\\Teams.exe'\n    filter_optional_onedrive:\n        Image|startswith: 'C:\\Users\\'\n        Image|contains: '\\AppData\\Local\\Microsoft\\OneDrive\\'\n    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*\nfalsepositives:\n    - Other legitimate processes loading those DLLs in your environment.\nlevel: medium\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1056.002","id":"T1056.002","name":"GUI Input Capture","page":"techniques/enterprise/T1056.002/"}],"data_path":"data/detection-rules/9ae01559-cf7e-4f8e-8e14-4c290a1b4784.json","kind":"sigma"}