. WatchGuard APT Blocker is a subscription-based service that adds another layer of UTM protection beyond signature-based antivirus.* Using a cloud-based sandbox to run Windows executable files Microsoft Office PDF files and Android APK it looks for malware characteristics including multiple types of evasive behaviour. *You must also have a subscription to Gateway Antivirus or the UTM Security Suite to enable APT Blocker to function. APT Blocker integrates with WatchGuard Dimension providing logs proactive alerts and full visibilty into any files detected as malware..