Caleb Sima, Founder and CTO Caleb is widely known within the Internet security community for his expertise in penetration testing and his ability to identify emerging security threats. He began his security career at the S1 Corporation in 1996. Caleb then joined Internet Security Systems as a member of the X-Force, where he focused on the research and development of security advisories for ISS. Some of his engineered exploits have gained media attention in publications such as the New York Times and the Washington Post. He has also been featured in US News and World Report and Security World magazine.