Query: Sigma YAML for windows / registry_set
Matching 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
Near-miss passage: Sigma rule: Detects the image load of VSS DLL by uncommon executables. Logsource: windows / image_load. Rule: title: Suspicious Volume Shadow Copy Vssapi.dll Load id: 37774c23-25a1-4adb-bb6d-8bb9fd59c0f8 related: - id: 333cdbe8-27bb-4246-bf82-b41a0dca4b70 type: similar - id: 48bfd177-7cf2-412b-ad77-baf923489e82 type: similar status: test description: Detects the image load of VSS DLL by uncommon executables references: - https://github.com/ORCx41/DeleteShadowCopies author: frack113 date: 2022-10-31 modified: 2026-05-18 tags: - attack.impact - attack.t1490 logsource: category: image_load product: windows detection: selection: ImageLoaded|endswith: \vssapi.dll filter_main_windows: - Image: - C:\Windows\explorer.exe - C:\Windows\ImmersiveControlPanel\SystemSettings.exe - Image|startswith: - C:\Windows\System32\ - C:\Windows\SysWOW64\ - C:\Windows\Temp\{ - C:\Windows\WinSxS\ - C:\$WinREAgent\Scratch\ filter_main_program_files: Image|startswith: - C:\Program Files\ - C:\Program Files (x86)\ filter_main_null_image: Image: null filter_optional_programdata_packagecache: Image|startswith: C:\ProgramData\Package Cache\ filter_optional_avira: Image|contains|all: - \temp\is- - \avira_system_speedup.tmp condition: selection and not 1 of filter_main_* and not 1 of filter_optional_* falsepositives: - Unknown level: high