Query: detection rule: Detects when an attacker adds a new AMSI provider via the Windows Registry to bypass AMSI (Antimalware Scan Interface) p
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 activity when a security-enabled global group is deleted. Logsource: windows / security. Rule: title: A Security-Enabled Global Group Was Deleted id: b237c54b-0f15-4612-a819-44b735e0de27 related: - id: 9cf01b6c-e723-4841-a868-6d7f8245ca6e type: obsolete status: stable description: Detects activity when a security-enabled global group is deleted references: - https://www.cisecurity.org/controls/cis-controls-list/ - https://www.pcisecuritystandards.org/documents/PCI_DSS_v3-2-1.pdf - https://nvlpubs.nist.gov/nistpubs/CSWP/NIST.CSWP.04162018.pdf - https://www.ultimatewindowssecurity.com/securitylog/encyclopedia/event.aspx?eventID=4730 - https://www.ultimatewindowssecurity.com/securitylog/encyclopedia/event.aspx?eventID=634 author: Alexandr Yampolskyi, SOC Prime date: 2023-04-26 tags: - attack.privilege-escalation - attack.persistence - attack.t1098 logsource: product: windows service: security detection: selection: EventID: - 4730 - 634 condition: selection falsepositives: - Unknown level: low