Abstract: A security management system provides rules for monitoring network activity of applications to groups of host, computers, specifically activity indicating that communications mechanisms have been established (i.e. open TCP ports) but are receiving little or no use (i.e., few connection acceptances). Agents on the hosts utilize monitoring software inserted between the applications and the network protocol stacks. The agents store network activity data gathered during the monitoring in local storage, and periodically upload the data to a centralized server in a compressed and optionally encrypted fashion. The server uses the uploaded data from all hosts to update a security management database reflecting the network activity of all the hosts. Reports may be generated to identify activity that may present security risks, such as open but inactive ports, to enable a network administrator to take remedial action such as de-activating or de-installing applications.