Security notes

Application-level filtering and system-level filtering

Sophos Client Firewall does both application-level filtering and system-level filtering. Sophos Client Firewall's filters intercept Transport Driver Interface (TDI) and Network Driver Interface Specification (NDIS) requests. This allows them to filter both application and system activity.

Stealth mode

Sophos Client Firewall puts your computer into stealth mode.

Normally when a computer receives a connection request from another computer, it lets the other computer know whether that port is open or closed. In stealth mode your computer does not respond, making it appear to be switched off or disconnected from the network.

Trojan blocking

Sophos Client Firewall can block a Trojan even if it resides in a driver or sends information directly to a hacker. All traffic is filtered.