This paper proposes an easily attachable/detachable proxy that helps ordinary computer users detect their personal information leakage caused by malicious software. This proxy can behave as a stealth proxy or as a transparent proxy, meaning that the proxy can be placed at any point in a TCP/IP network. Users of this proxy can detect and stop any suspicious TCP/IP connections by placing the proxy at any appropriate point in their network and by using the bundled controller Web application that controls behavior of the proxy. We have used a Raspberry Pi and HTML5 for the proxy implementation, thus making this method affordable and portable. We evaluated the proxy by placing it at several places in the network, and confirmed that the proxy properly works and helps users detect suspicious TCP/IP connections by visualizing them between their computers and the Internet.