Query: Sigma YAML for windows / image_load
Matching passage: Sigma rule: Detects loading of "credui.dll" and related DLLs by an uncommon process. Attackers might leverage this DLL for potential. Logsource: windows / image_load. Rule: title: CredUI.DLL Loaded By Uncommon Process id: 9ae01559-cf7e-4f8e-8e14-4c290a1b4784 status: test 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". 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 author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research) date: 2020-10-20 modified: 2026-06-29 tags: - attack.credential-access - attack.collection - attack.t1056.002 logsource: category: image_load product: windows detection: selection: - ImageLoaded|endswith: - \credui.dll - \wincredui.dll - OriginalFileName: - credui.dll - wincredui.dll filter_main_generic: Image|startswith: - C:\Program Files (x86)\ - C:\Program Files\ - C:\Windows\System32\ - C:\Windows\SysWOW64\ - C:\Windows\SystemApps\ filter_main_full: Image: - C:\Windows\explorer.exe - C:\Windows\ImmersiveControlPanel\SystemSettings.exe - C:\Windows\regedit.exe filter_optional_opera: Image|endswith: \opera_autoupdate.exe filter_optional_process_explorer: Image|endswith: - \procexp64.exe - \procexp64a.exe - \procexp.exe filter_optional_teams: Image|startswith: C:\Users\ Image|contains: \AppData\Local\Microsoft\Teams\ Image|endswith: \Teams.exe filter_optional_onedrive: Image|startswith: C:\Users\ Image|contains: \AppData\Local\Microsoft\OneDrive\ condition: selection and not 1 of filter_main_* and not 1 of filter_optional_* falsepositives: - Other legitimate processes loading those DLLs in your environment. level: medium
Near-miss passage: Sigma rule: Detects when an attacker adds a new AMSI provider via the Windows Registry to bypass AMSI (Antimalware Scan Interface) p. Logsource: windows / registry_set. Rule: title: Potential Persistence Via New AMSI Providers - Registry id: 33efc23c-6ea2-4503-8cfe-bdf82ce8f705 status: test description: 'Detects when an attacker adds a new AMSI provider via the Windows Registry to bypass AMSI (Antimalware Scan Interface) protections. Attackers may add custom AMSI providers to persist on the system and evade detection by security software that relies on AMSI for scanning scripts and other content. This technique is often used in conjunction with fileless malware and script-based attacks to maintain persistence while avoiding detection. ' references: - https://persistence-info.github.io/Data/amsi.html - https://github.com/gtworek/PSBits/blob/8d767892f3b17eefa4d0668f5d2df78e844f01d8/FakeAMSI/FakeAMSI.c author: Nasreddine Bencherchali (Nextron Systems) date: 2022-07-21 modified: 2025-10-26 tags: - attack.persistence logsource: category: registry_set product: windows detection: selection: TargetObject|contains: - \SOFTWARE\Microsoft\AMSI\Providers\ - \SOFTWARE\WOW6432Node\Microsoft\AMSI\Providers\ filter_optional_avast: Image: - C:\Program Files\Avast Software\Avast\RegSvr.exe - C:\Program Files\Avast Software\Avast\x86\RegSvr.exe TargetObject|contains: \{FB904E4E-D2C7-4C8D-8492-B620BB9896B1} filter_optional_avg: Image: - C:\Program Files\AVG\Antivirus\RegSvr.exe - C:\Program Files\AVG\Antivirus\x86\RegSvr.exe TargetObject|contains: \{FB904E4E-D2C7-4C8D-8492-B620BB9896B1} filter_optional_avira: Image: C:\Program Files\Avira\Endpoint Protection SDK\endpointprotection.exe TargetObject|contains: \{00000001-3DCC-4B48-A82E-E2071FE58E05} condition: selection and not 1 of filter_optional_* falsepositives: - Legitimate security products adding their own AMSI providers. Filter these according to your environment. level: medium regression_tests_path: regression_data/rules/windows/registry/registry_set/registry_set_persistence_amsi_providers/info.yml