Windows EDRSilencer Custom Outbound Filter Added
The following analytic detects the EDRSilencer-specific Windows Filtering Platform filter name "Custom Outbound Filter" when it is configured with a block action. EDRSilencer creates WFP filters to block outbound…
Description
The following analytic detects the EDRSilencer-specific Windows Filtering Platform filter name "Custom Outbound Filter" when it is configured with a block action. EDRSilencer creates WFP filters to block outbound traffic from EDR and security agent processes, impairing endpoint telemetry without requiring the tool binary to keep its original process name. EventCode 5447 identifies creation of the runtime filter with ChangeType %%16384, while EventCode 5441 can show the same persistent filter when the Base Filtering Engine starts.
Detection logic
Detection requirements
- Platform
- ContainersESXiIaaSLinuxmacOSNetwork DevicesWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- windows_event_log_security_5441windows_event_log_security_5447
Known benign triggers
- This filter name is associated with EDRSilencer behavior. Validate whether any approved administrative tooling creates WFP block filters with the same name before tuning.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| github.com/mthcht/awesome-lists/blob/main/Lists/Others/windows%20message%20tables/windows_messagetable_strings_list.csv | Only this detection cites it |
| github.com/netero1010/EDRSilencer | 6from 2 sources |
| learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-10/security/threat-protection/auditing/event-5447 | 2 |
| learn.microsoft.com/en-us/windows/win32/fwp/auditing-and-logging | 2 |
From the source
- At source
- Open at source
- Upstream identifier
- 67fea630-445d-4c70-a7d0-584fddb93b86
- Tagged by the source as
- Disabling Security ToolsSecurity Solution TamperingEndpointendpointSplunk CloudSplunk EnterpriseSplunk Enterprise Securityendpoint
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Aug 26, 2026
- Version
- 1