There is a big bunch of tools offering HTTP/SSL traffic interception. However, when it comes to penetration tests of specialized embedded software or thick clients, we often encounter proprietary protocols with no documentation at all. Binary TCP connections, unlike anything, impossible to be adapted by a well-known local proxy. Without disassembling the protocol, pentesting the server backend is very limited. Though, based on our experience, it very often hides a shameful secret - completely unsecured mechanisms breaking all secure coding practices. To demonstrate, we will show a few case-studies - most interesting examples from real-life industry software, which in our opinion are a quintessence of "security by obscurity". We will challenge the security of proprietary protocols in pull printing solutions, FOREX trading software, remote desktops and home automation technologies.