Stiltwalker is a system we designed to break the audio version of reCAPTCHA. At LayerOne, the original stiltwalker was released. However reCAPTCHA updated its system to break stiltwalker in the hours before our talk/release. Prior to these changes, stiltwalker was able to achieve an accuracy of 99.1%. This talk will go over some of the counter-countermeasures we implemented to break the audio version of reCAPTCHA again, the original solving techniques used, and a few other related things we've been working on.
DC-949 was founded at some point in 2004, and has slowly amassed members of like minded and passionate hackers. Although group attendance rises and falls, some of the core members are Dr. Adam Nichols, Adrian, C-P, Frank^2, Jeffball, Savant, Sintax Error, and Vyrus. In addition to previously running the oCTF contest at DefCon, and the Barcode Shmarcode contest at Shmoocon, DC-949 members have given talks at numerous conferences including LayerOne, Outerz0ne, Thotcon, and DefCon. They have also released several proof of concept applications including Skynet, TwatFS, and Floodgate.