Personal firewall

A personal firewall (also referred to as a desktop firewall) is a software application used to monitor and control the inbound and outbound internet traffic from a computer in order to prevent unauthorised access from intruders.

Unlike a standard firewall on your computer's operating system, a personal firewall is able to filter outgoing connections as well as inbound; it can be set to your own personal security level preferences and will alert you of any suspicious or malicious activity.   

There are a number of free and commercial personal firewall programmes available online.