Fatih Ozavci is a Security Researcher and Senior Consultant with Sense of Security. He is the author of the Viproy VoIP Penetration and Exploitation Testing Kit and MBFuzzer Mobile Application MITM Fuzzer tool and he has also published a paper about Hacking SIP Trust Relationships. Fatih has discovered many unknown security vulnerabilities and design and protocol flaws in VoIP environments for his customers, and analyses VoIP design and implementation flaws, which help to improve VoIP infrastructures. Additionally, he has completed numerous mobile application penetration testing services including but not limited to reverse engineering of mobile applications, exploiting mobile services level vulnerabilities, and attacking data transporting and storing features of mobile applications. His current research is based on attacking mobile VoIP clients, VoIP service level vulnerabilities, web based VoIP and video conference systems, decrypting custom mobile application protocols, and MITM attacks for mobile applications. While Fatih is passionate about VoIP penetration testing, mobile application testing and IPTV testing, he is also well versed at network penetration testing, web application testing, reverse engineering, fuzzing, and exploit development. Fatih presented his VoIP research and tool in 2013 at DEF CON 21 (USA), Black Hat Arsenal USA 2013, Cluecon 2013 (USA), Athcon 2013 (Greece), Ruxcon 2013 and AusCERT 2014. Also Fatih will present "VoIP Wars: Attack of the Cisco Phones" session at Black Hat USA 2014 and DEF CON 22 (USA).