Welcome Thrillhouse Group

Welcome Thrillhouse Group competed in the SOHOpelessly Broken CTF in the IoT Village at DEF CON 26 this year. None of the actual team, aside from myself, was able to make it this year. So, I requested the help of my colleagues and "Mitch" was keen to help. Together, we reached 14th place by the end of Saturday with 9k points. WTG's Score by End of Saturday As you can see, we had a couple issues submitting flags. For this CTF, flags were typically the MD5 of something under /dev or something like a clear text password. When our flags failed to submit, we worked with the organizers and chalked it up to someone modifying the flag files so that the MD5 would change. These issues had no impact on our score, accomplished nothing, was a jerk-move, and as can be seen below; was against the rules: IoT CTF Rules and Hints The CTF consisted of 22 challenges based on the 22 devices seen below: IoT CTF Device Challenges WTG successfully completed the challe...

I'm patiently waiting for the 2018 Defcon IoT CTF and thought I'd stay in the habit of blogging by revisiting the CryptoToken challenge that  @TrimarcSecurity  held at ShmooCon 2018. CryptoTokens and Challenge Coin The challenge was meant to be fun, easy, and get you to talk with vendors. The way it worked was that once you solved the first challenge, you had to find the vendor that had the second challenge, then the third, and so on obtaining a new CryptoToken with each solve. The prize for solving all of the puzzles was a challenge coin and a shirt. I'm a sucker for a challenge coins, so  @PLeXuSECU  and I grabbed the first token and got to work. First Token We immediately recognized the Letter Number cipher and solved this one by hand. Had cell service been a little stronger in the Hilton's basement, we might have used Rumkin's Letter Number Solver found  here .        Letter Number: 19-23-15-18-4-6-9-19-8 (SWORD...

2021 Update : This is currently the most read post on our blog. Chances are that you are here because you are working on an audio challenge. If you see something looking like a digital signal, be sure to also check out our Radioactive Man write-up. I have stumbled across a few audio files while competing in CTFs over the last few years and I thought covering spectrograms would make a nice and quick blog post. Flags can manifest themselves in many ways when dealing with media files. One of the most common ways I have seen is by hiding them, or clues to find them, in the file's audio spectrogram. According to wikipedia: "a spectrogram is a visual representation of the spectrum of frequencies of sound, or other signals, as they vary with time." Basically, it is a method to visualize sound and signals. I first learned that you can embed hidden messages and images in a spectrogram when a friend showed me an image from an Aphex Twin song some years ago. Equation by ...

Welcome Thrillhouse Group is a hacking team based out of North Carolina. We do CTFs and writeup some of our findings. You can find me on twitter @strupo_ - strupo_