. Watch Guard 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 & 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 Watch Guard Dimension providing logs proactive alerts & full visibilty into any files detected as malware..