Symantec ProxySG providing content filtering must detect use of network services that have not been authorized or approved by the ISSM and ISSO, at a minimum.

Unauthorized or unapproved network services lack organizational verification or validation and therefore may be unreliable or serve as malicious rogues for valid services. Examples of network services include service-oriented architectures (SOAs), cloud-based services (e.g., infrastructure as a service, platform as a service, or software as a service), cross-domain, Voice over Internet Protocol, Instant Messaging, auto-execute, and file sharing. To comply with this requirement, the ALG may be configured to detect services either directly or indirectly (i.e., by detecting traffic associated with a service). This requirement applies to gateways/firewalls that perform content inspection or have higher-layer proxy functionality. ProxySG is a default-deny device and only permits authorized/approved network services to be used.