Hands Off! 4.0.0 [ HD ]

: A popular, free, open-source firewall specifically for monitoring outgoing connections.

: Beyond network monitoring, it can block applications from reading or writing to specific files on your disk to protect sensitive data. Hands Off! 4.0.0

Since the tool is no longer actively maintained, you might consider these current industry standards for Mac security: : A popular, free, open-source firewall specifically for

HandsOff an Ultimate Firewall for your Mac | Lucideus Research : When an application attempts an operation without

: It tracks both inbound and outbound network connections to prevent applications from "phoning home".

: When an application attempts an operation without a defined rule, a notification appears with detailed information (Process ID, IP address, port) to help you decide whether to allow or block it.

: Known for its sophisticated Network Monitor , which features an animated map of connections and a "Research Assistant" to help you understand unknown connection attempts.