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Filter Rules

Noise reduction rules that suppress known benign activity to reduce false positives.

5 rules in this category.

Rule Summary

ID Title Level ATT&CK
wf-filter-001 Internal Scanner False Positive Filter medium T1046
wf-filter-002 Backup Transfer False Positive Filter medium T1048
wf-filter-003 Service Account Auth False Positive Filter medium T1110
wf-filter-004 CDN/Health Check DNS False Positive Filter medium T1071.004
wf-filter-005 Monitoring Agent Connection False Positive Filter medium T1071

Rule Details

Internal Scanner False Positive Filter

ID: wf-filter-001
Level: medium
Status: stable
Author: WitFoo

Filters out port scan detections originating from known authorized vulnerability scanners and asset discovery tools. Customize the scanner IP list to match your environment.

Tags: attack.discovery, attack.t1046

Detection Logic
  • messageType: service_discovery

Backup Transfer False Positive Filter

ID: wf-filter-002
Level: medium
Status: stable
Author: WitFoo

Filters out large data transfer alerts caused by authorized backup operations. Customize the backup server IPs and schedule windows to match your backup infrastructure.

Tags: attack.exfiltration, attack.t1048

Detection Logic
  • totalBytes: 104857600

Service Account Auth False Positive Filter

ID: wf-filter-003
Level: medium
Status: stable
Author: WitFoo

Filters out authentication failure events from known service accounts. Service accounts may generate periodic auth failures during credential rotation or configuration changes. Customize the service account list to match your environment.

Tags: attack.credential_access, attack.t1110

Detection Logic
  • messageType: auth_failure

CDN/Health Check DNS False Positive Filter

ID: wf-filter-004
Level: medium
Status: stable
Author: WitFoo

Filters out DNS tunneling false positives caused by CDN health check domains, cloud service discovery domains, and other legitimate long DNS names. Customize domain patterns to match your environment.

Tags: attack.command_and_control, attack.t1071.004

Detection Logic
  • protocol: DNS

Monitoring Agent Connection False Positive Filter

ID: wf-filter-005
Level: medium
Status: stable
Author: WitFoo

Filters out long-lived connection alerts from known monitoring agents and management tools that maintain persistent connections by design. Customize agent patterns to match your monitoring infrastructure.

Tags: attack.command_and_control, attack.t1071

Detection Logic
  • messageType: anomalous_behavior