Thursday, September 24, 2015

Writeup - CSAW 2015 : Recon 100 - Eric Liang



We were originally given just the above sentence to track down the mysterious Eric Liang. A quick recon of the CSAW page told us that he was an NYU student, class of 2016. According to the CSAW bio he had competed in the CTF the previous two years.
Initial searches showed that there were several Eric Liangs who lived in New York and several others who were involved in computer science. The correct Eric Liang, Eric Zhi Liang, was quickly identified but not before other options were investigated. At least one Eric Liang seemed very excited by the amount of traffic on his website. Utilizing google and various search techniques, as well as a contact who attended NYU. We were able to track down a significant amount of information on Eric, ranging from his various Steam profiles to his wife’s name and address. However, none of these routes turned up the flag.
After reviewing the challenge and deciding to backtrack some, the archived CSAW pages from 2013 and 2014 were searched. On the team listing for the 2014 competition, we searched for teams from NYU POLY. We then quickly found the team that Eric played on as well as the flag.