Sorry, Wrong Number: Mysteries Of The Phone System - Past and Present presented at Defcon 2015

by Patrick Mcneil, Snide Owen,

Summary : Exploring the phone system was once the new and exciting realm of “phone phreaks,” an ancestor of today’s computer “hackers.” The first phreaks “owned” and explored the vague mysteries of the telephone network for a time until their activities drew too much attention from the phone companies and law enforcement. The phone system evolved, somewhat, in an attempt to shut them out, and phreaking became both difficult and legally dangerous. Such events paralleled a new personal computer “revolution” wherein phone phreaks made the transition from the secret subtleties of telephony to the new and mystical frontier of personal computing. Private BBS(s) and, eventually, the Internet was not only the next logical step forward, but also provided “safer” alternatives that still allowed for the thrill of exploring the mysteries of a new modern age. Telephony, and voice security in general, became, as the years passed, something of a lost art to all but those who remember...
In this presentation we begin our adventure with a journey back in time, starting in the post-war Film Noir era of the 40’s and 50’s, when users required an operator at the switchboard to make a call, investigating some of the early roots of phreaking that many have forgotten. We will briefly take a look at the weaknesses of early telephone systems and the emergence of the original phreaks in the 50’s and 60’s who found and exploited them. Our journey will also allow us to demonstrate how some of the same basic phreaking approaches are still applicable to today’s "advanced" VoIP systems.
Certainly the initial creation and emergence of VoIP opened a variety of attack vectors that were covered at security conferences at the time. Commercial VoIP adoption, however, remained stagnant until standards and carriers caught up. Some VoIP hacking tools were left unmaintained, and VoIP wasn’t the sexy and mysterious attack vector it once was with the exception of tricksters who found old or insecure systems to be easy targets. Due to increased VoIP adoption over the last few years, however, telephony attacks are provocative once again.
As hardboiled VoIP detectives, we’ll unravel the mysteries of the curious, shadowy, and secretive world of phreaks, tricksters, and VoIP hackers. We’ll compare and contrast old school phreaking with new advances in VoIP hacking. We’ll explain how voice systems are targeted, how they are attacked using old and new methods, and how to secure them - with demonstrations along with practical and actionable tips along the way. We may even drop a new VoIP telephony phishing tool to fuse the past and the present..