Conference 39th Chaos Communications Congress

One

Protecting the network data of one billion people: Breaking network crypto in popular Chinese mobile apps (en)

Mona

In this talk, I will describe how my team and I systematically exploited around a dozen home-rolled network encryption protocols used by popular mobile apps like RedNote, Alipay, and some of the most popular mobile browsers in China to encrypt sensitive information. I'll demonstrate how network eavesdroppers could access users' browsing history and mobile activity. This is a systemic issue; despite our work on the above protocols and the resulting vulnerability disclosures, this plague of home-rolled and proprietary encryption is still at large. I will end by discussing how we got here, re-affirm the age-old adage, “Don’t roll your own crypto!”, and call on hackers around the world to help us move towards HTTPS everywhere.

Skynet Starter Kit: From Embodied AI Jailbreak to Remote Takeover of Humanoid Robots (en)

Shipei Qu, Zikai Xu, Xuangan Xiao

We present a comprehensive security assessment of Unitree's robotic ecosystem. We identified and exploited multiple security flaws across multiple communication channels, including Bluetooth, LoRa radio, WebRTC, and cloud management services. Besides pwning multiple traditional binary or web vulnerabilities, we also exploit the embodied AI agent in the robots, performing prompt injection and achieve root-level remote code execution. Furthermore, we leverage a flaw in cloud management services to take over any Unitree G1 robot connected to the Internet. By deobfuscating and patching the customized, VM-based obfuscated binaries, we successfully unlocked forbidden robotic movements restricted by the vendor firmware on consumer models such as the G1 AIR. We hope our findings could offer a roadmap for manufacturers to strengthen robotic designs, while arming researchers and consumers with critical knowledge to assess security in next-generation robotic systems.

CCC-Jahresrückblick (de)

Constanze Kurz, khaleesi, Matthias Marx, Linus Neumann, erdgeist

Das war nicht das Jahr 2025, das wir bestellt hatten.

freiheit.exe - Utopien als Malware (de)

Christiane Mudra

"freiheit.exe“ ist eine Lecture über die ideologischen Rootkits des Silicon Valley. Sie schlägt den Bogen von den italienischen Futuristen zu den heutigen Tech-Feudalisten, vom Akzelerationismus zur Demokratieskepsis der Libertären, von Tolkien zur PayPal-Mafia. Basierend auf den Recherchen zu meinem Theaterstück "freiheit.exe. Utopien als Malware", in dem journalistische Analyse auf performative Darstellung trifft.

Verlorene Domains, offene Türen - Was alte Behördendomains verraten (de)

Tim Philipp Schäfers (TPS)

Was passiert, wenn staatliche Domains auslaufen - und plötzlich jemand anderes sie besitzt? In diesem Vortrag wird berichtet, wie mehrere ehemals offizielle, aber unregistrierte Domains deutscher Bundesministerien und Behörden erworben werden konnten - und welche Datenströme dadurch sichtbar wurden. Über Monate hinweg konnten so DNS-Anfragen aus Netzen des Bundes empfangen werden - ein erhebliches Sicherheitsrisiko. Unter anderem da es so möglich war Accounts zu übernehmen, Validierungen von E-Mailsignaturen zu manipulieren, Anfrage umzuleiten und im Extremfall Code auf Systemen auszuführen. (Keine sensiblen Daten werden veröffentlicht; der Fokus liegt auf Forschung, Aufklärung und verantwortungsvollem Umgang mit den Ergebnissen.)

Don’t look up: There are sensitive internal links in the clear on GEO satellites (en)

Nadia Heninger, Annie Dai

We pointed a commercial-off-the-shelf satellite dish at the sky and examined all of the geostationary satellite communications visible from our vantage point. A shockingly large amount of sensitive traffic is being broadcast unencrypted, including critical infrastructure, internal corporate and government communications, private citizens’ voice calls and SMS, and consumer Internet traffic from in-flight wifi and mobile networks.

Code to Craft: Procedural Generation for the Physical World (en)

bleeptrack

Join bleeptrack for a deep dive into the fascinating world of procedural generation beyond the screen. From stickers and paper lanterns to PCBs, furniture, and even physical procedural generators, this talk explores the challenges and creative possibilities of bringing generative projects into tangible form.

Ground

Junghacker:innentag Einführung (de)

Zu unserer Freude haben sich in den letzten Jahren immer mehr Junghacker:innen auf dem Congress eingefunden. Daher bieten wir auch diesmal, wie schon in den Vorjahren, einen speziell auf Kinder und Jugendliche zugeschnittenen Junghacker:innentag an. Am zweiten Congresstag, dem 28. Dezember 2024, organisieren Freiwillige aus vielen Assemblies von etwa 10 bis 17 Uhr ein vielseitiges Workshop-Programm für angehende Hacker:innen.

Persist, resist, stitch (en)

Philo

What does knitting have to do with espionage? Can embroidery help your mental health? This talk shows how the skills to create textile art have enabled people to resist and to persist under oppressive regimes for centuries. And it offers ways to keep doing so.

CSS Clicker Training: Making games in a "styling" language (en)

Lyra Rebane

CSS is a programming language, and you can make games in it. Let's install NoScript and make some together!

51 Ways to Spell the Image Giraffe: The Hidden Politics of Token Languages in Generative AI (en)

Ting-Chun Liu, Leon-Etienne Kühr

Generative AI models don't operate on human languages – they speak in **tokens**. Tokens are computational fragments that deconstruct language into subword units, stored in large dictionaries. These tokens encode not only language but also political ideologies, corporate interests, and cultural biases even before model training begins. Social media handles like *realdonaldtrump*, brand names like *louisvuitton*, or even *!!!!!!!!!!!!!!!!* exist as single tokens, while other words remain fragmented. Through various artistic and adversarial experiments, we demonstrate that tokenization is a political act that determines what can be represented and how images become computable through language.

Zero

Lightning Talks - Tag 2 (de)

Bonnie, keldo, Andi Bräu

Lightning Talks - Tag 2

Agentic ProbLLMs: Exploiting AI Computer-Use and Coding Agents (en)

Johann Rehberger

This talk demonstrates end-to-end prompt injection exploits that compromise agentic systems. Specifically, we will discuss exploits that target computer-use and coding agents, such as Anthropic's Claude Code, GitHub Copilot, Google Jules, Devin AI, ChatGPT Operator, Amazon Q, AWS Kiro, and others. Exploits will impact confidentiality, system integrity, and the future of AI-driven automation, including remote code execution, exfiltration of sensitive information such as access tokens, and even joining Agents to traditional command and control infrastructure. Which are known as "ZombAIs", a term first coined by the presenter as well as long-term prompt injection persistence in AI coding agents. Additionally, we will explore how nation state TTPs such as ClickFix apply to Computer-Use systems and how they can trick AI systems and lead to full system compromise (AI ClickFix). Finally, we will cover current mitigation strategies and forward-looking recommendations and strategic thoughts.

Variable Fonts — It Was Never About File Size (en)

Bernd

A brief history of typographic misbehavior or intended and unintended uses of variable fonts. Nine years after the introduction of variable fonts, their most exciting uses have little to do with what variable fonts originally were intended for and their original promise of smaller file sizes. The talk looks at how designers turned a pragmatic font format into a field for experimentation — from animated typography and uniwidth button text to pattern fonts and typographic side effects with unintended aesthetics. Using examples from projects such as TypoLabs, Marjoree, Kario (the variable font that’s used as part of the 39C3 visual identity), and Bronco, we’ll explore how variable fonts evolved from efficiency tools into creative systems — and why the most interesting ideas often emerge when technology is used in unintended ways.

How To Minimize Bugs in Cryptography Code (en)

Jade

"Don't roll your own crypto" is an often-repeated aphorism. It's good advice -- but then how does any cryptography get made? Writers of cryptography code like myself write code with bugs just like anyone else, so how do we take precautions against our own mistakes? In this talk, I will give a peek into the cryptographer's toolbox of advanced techniques to avoid bugs: targeted testing, model checking, mathematical proof assistants, information-flow analysis, and more. None of these techniques is a magic silver bullet, but they can help find flaws in reasoning about tricky corner cases in low-level code or prove that higher-level designs are sound, given a defined set of assumptions. We'll go over some examples and try to give a high-level feel for different workflows that create "high-assurance" code. Whether you know it or not, you use this type of cryptography code every day: in your browser, your messaging apps, and your favorite programming language standard libraries.

When Vibe Scammers Met Vibe Hackers: Pwning PhaaS with Their Own Weapons (en)

Chiao-Lin Yu (Steven Meow)

What happens when AI-powered criminals meet AI-powered hunters? A technical arms race where both sides are vibing their way through exploitation—and the backdoors write themselves. In October 2025, we investigated Taiwan's fake delivery scam ecosystem targeting convenience store customers. What started as social engineering on social media became a deep dive into two distinct fraud platforms—both bearing the unmistakable fingerprints of AI-generated code. Their developers left more than just bugs: authentication flaws, file management oversights, and database implementations that screamed "I asked LLM and deployed without reading." We turned their sloppiness into weaponized OSINT. Through strategic reconnaissance, careful database analysis, and meticulous operational security, we achieved complete system access on multiple fraud infrastructures. By analyzing server artifacts and certificate patterns, we mapped 100+ active domains and extracted evidence linking thousands of victim transactions worth millions of euros in fraud. But here's the twist: we used the same AI tools they did, just with better prompts. The takeaway isn't just about hunting scammers—it's about the collapse of the skill gap in both offense and defense. When vibe coding meets vibe hacking, the underground economy democratizes in ways we never anticipated. We'll share our methodology for fingerprinting AI-assisted crime infrastructure, discuss the ethical boundaries of counter-operations, and demonstrate how to build sustainable threat intelligence pipelines when your adversary can redeploy in 5 minutes. This talk proves that in 2025, the real exploit isn't zero-day—it's zero-understanding.

The Small Packet of Bits That Can Save (or Destabilize) a City (en)

Manuel Rábade

The Emergency Alert System (EAS) and its SAME (Specific Area Message Encoding) protocol are public alerting technologies that broadcast short digital bursts over VHF triggering emergency messages on millions of receivers across North America. In Mexico, this technology was integrated into the Seismic Alert System (SASMEX) which more than 30 million people in the central part of the country rely on to prepare for frequent earthquakes. While new alerting technologies have emerged, the EAS-SAME network continues to play an important role for public safety in the U.S., Mexico, and Canada. Yet, the same small packets of bits that can help protect a city could also, in the wrong hands, destabilize it. This talk examines how these systems operate and reveals a troubling truth: spoofing these alerts is far easier than most people expect.

Fuse

Neue Chaos Events - InselChaos und Håck ma’s Castle plaudern aus dem Nähkästchen (de)

Erwin Ernst "eest9" Steinhammer, lasii, Daniel, Niklas

Auf der Insel Rügen und in Österreich tut sich was - und zwar neue Chaos Events. Wir möchten über Anforderungen, Herausforderungen, Hürden, Erfahrungen und Glücksmomente aus unserer Sicht der Orga erzählen. Das InselChaos fand im LaGrange e.V. im September 2025 statt und bildet den Auftakt für weitere kreative, informative und chaotische Events auf der Insel Rügen. Das Håck ma’s Castle wird mit etwas Humor auch über Herausforderungen sprechen, welche unter anderem durch dezentrale Teams aus diversen Hackspaces entstehen.

Power Cycle B7 oder Warum kauft man eine Zeche? (de)

Kohlenpod, kater, Stephan

Aus einem Barwitz wurde ein Projekt! Blumenthal7 ist die letzte vollständig erhaltene Schachtanlage des ehemaligen Steinkohlebergwerks General Blumenthal in Recklinghausen im nördlichen Ruhrgebiet. Nach diversen Startschwierigkeiten ist aus einer im Dornröschenschlaf liegenden Industriebrache ein Projekt geworden, das bereits jetzt einer Vielzahl von Entitäten und Gruppen eine Heimat und einen großen, nahezu grenzenlosen Spielplatz bietet. Begleitet uns gerne beim Power Cycle B7…!

A Quick Stop at the HostileShop (en)

Mike Perry

HostileShop is a python-based tool for generating prompt injections and jailbreaks against LLM agents. I created HostileShop to see if I could use LLMs to write a framework that generates prompt injections against LLMs, by having LLMs attack other LLMs. It's LLMs all the way down. HostileShop generated prompt injections for a winning submission in OpenAI's GPT-OSS-20B RedTeam Contest. Since then, I have expanded HostileShop to generate injections for the entire LLM frontier, as well as to mutate jailbreaks to bypass prompt filters, adapt to LLM updates, and to give advice on performing injections against other agent systems. In this talk, I will give you an overview of LLM Agent hacking. I will cover LLM context window formats, LLM agents, agent vulnerability surface, and the prompting and efficiency insights that led to the success of HostileShop.

How to render cloud FPGAs useless (en)

Dirk

While FPGA developers usually try to minimize the power consumption of their designs, we approached the problem from the opposite perspective: what is the maximum power consumption that can be achieved or wasted on an FPGA? Short answer: we found that it’s easy to implement oscillators running at 6 GHz that can theoretically dissipate around 20 kW on a large cloud FPGA when driving the signal to all the available resources. It is interesting to note that this power density is not very far away from that of the surface of the sun. However, such power load jump is usually not a problem as it will trigger some protection circuitry. This led us to the next question: would a localized hotspot with such power density damage the chip if we remain within the typical power envelope of a cloud FPGA (~100 W)? While we could not “fry” the chip or induce permanent errors (and we tried several variants), we did observe that a few routing wires aged to become up to 70% slower in just a few days of stressing the chip. This basically means that such an FPGA cannot be rented out to cloud users without risking timing violations. In this talk, we will present how we optimized power wasting, how we measured wire latencies with ps accuracy, how we attacked 100 FPGA cloud instances and how we can protect FPGAs against such DOS attacks.

Machine Vision – Vom Algorithmus zum Baumpilz im digitalen Metabolismus (de)

Thomas Knüsel

Milliarden von Kameras produzieren täglich Bilder, die zunehmend von Maschinen analysiert werden. In dieser Lecture Performance beleuchten wir die Entwicklung des maschinellen Sehens – von den frühen algorithmischen Ansätzen bis zu den heutigen Anwendungen – und schauen, wie verschiedene Künstler:innen diese Technologien nutzen und reflektieren. Anhand der beiden Arbeiten „Throwback Environment” und „Fomes Fomentarius Digitalis” betrachten wir die Nutzung des maschinellen Sehens in einem künstlerischen Feedback-Loop. Die Arbeiten machen sichtbar, was die eingesetzten Algorithmen sehen und in welchen Mustern sie operieren.

Am Spätverkauf

A blast from the Y2K past… GRÜNSPAN (Rock & Metal) (en)

Alex Thurow

A time travel DJ set back to the times of the millennium change… … to the times of the prevented [Y2K apocalypse](https://en.wikipedia.org/wiki/Year_2000_problem) … to the times of the [Dot-com bubble](https://en.wikipedia.org/wiki/Dot-com_bubble) (… it’s about time AI, isn’t it?) … to the times of a [VERY problematic seed being planted](https://en.wikipedia.org/wiki/2000_Russian_presidential_election) … but most importantly to the times of the glorious: [| G.--. || R.--. || Ü.--. || N.--. || S.--. || P.--. || A.--. || N.--. |](https://www.gruenspan.de/) Back when ROCK was alive and kickin’ in „Hamburg meine Perle“! So, if you want to get a LOUD blast from the past - come join us and bring your [Pommesgabel](https://de.wikipedia.org/wiki/Mano_cornuta) with you! Live long and prosper, [DJ Alex](https://mstdn.social/@alexthurow/110279531725018974) (AKA: [https://onmoderndev.de](https://onmoderndev.de))

4ever punk (en)

DJ Baba Grande

one hour of punk music, encompassing many different styles

Chaos Computer Music Club

Sportbrigade Sparwasser (de)

Hüp Now

We are well aware of the fact, that as DJs we play other peoples´(as well as our own) music. This means we want to ensure the musicians get the credit and respect they deserve for their work. Whenever reasonably possible (communication get quite intense for us at times) we´ll be happy to supply track IDs, although sometimes it may take a little while. Also we´re happy about reposts if you like what we´re doing.

Hitstorm aka The Jakob Sister b2b RaverPik (en)

RaverPik

This DJ Team the combines all the Sachsentrance craziness :D since both DJs run the Sachsentrance Label and organize their famous events, widely known for their ecstatic vibes. It's pure Joy!

Tatendrang.wav (de)

Adnan

Seine Sets sind geprägt von düsteren, treibenden Beats und hypnotischen Grooves, die sich perfekt für Underground-Partys und nächtliche Dancefloors eignen. Tatendrang ist kein Mainstream-DJ, sondern ein klarer Szene-DJ, der sich auf spezielle, energiegeladene Sounds konzentriert und damit eine loyale Fangemeinde anspricht. Mit viel Gespür für Atmosphäre und Spannungsaufbau nimmt er sein Publikum mit auf eine intensive musikalische Reise.

MASCHA (de)

Mascha

DJ and music producer >>currently hosting MUSTER show every month at @thfradio

Chill Floor

Etai Darway (de)

Etai Darway

Dj Set Etai Darway

chaeza + doc (de)

chaeza + doc

Dj Set

Weebz (en)

Weebz

WEEBZ likes to move between the odds, the rough and the soft: Breakbeat, dissonances, noise and sounds of deep dungeons belong to their mixes as well as the hymns of our hearts Most of the time the genres are mixed to an eclectic collection mirroring own confusions in the spirit of making the unmatching matching xx

Fimi & Nush (de)

Hanni

Fimi&Nush

Felix Kubin (de)

Felix Kubin

Felix Kubin, funkensprühender Spannungs- und Weltenwandler aus Hamburg, Verachter der Nüchternheit, lenkt die musikalische Kompassnagel Richtung Stolperdisko, Art Pop und „gute Nervmusik“. Das Tanzbein zappelt, aber die Beine laufen in verschiedene Richtungen, denn sie haben sich noch nicht synchronisiert. Hier erklingen Songs am Rande des Nervenzusammenbruchs, "Musik für junge Leute" und alle, die nicht sterben wollen. Vor allem haben es ihm die obskuren Musikversuche der Heimstudios vergangener Fostex-Generationen angetan, die Art Brut und ihre Einfärbungen durch billige, leicht zu demolierende Technologien. Felix Kubins musikalische Adoleszenz wurde durch eine Zeit geprägt, in der sich die Szenen der Kunst und Musik stark durchdrangen und Songtitel wie "Die Gesunden kommen", "Adrenalin lässt das Blut kochen" und "Hosen, die nicht aneinander passen" kein Stirnrunzeln verursachten. Eine Zeit also, in der sich die Popmusik weit aus dem Fenster lehnte und die Luft einer fremden, seltsamen Welt atmete.

Lina & Nele & Peng (de)

Lina & Nele & Peng

Nele, Peng and Lina are set to create a mesmerizing experience on the chillfloor 3c39, blending their unique artistic visions into a cohesive musical journey.Lina, with her innate talent and meticulous attention to detail, weaves ethereal melodies, esoteric rhythms, and wavey melancholy into a rich narrative. As an experienced curator of sound and atmosphere, she infuses her sets with her personal journey and history, selecting tracks that evoke deep emotions and resonate with her favorites.Nele and Peng complement Lina's artistry with their exceptional taste and ability to craft transcendental musical experiences. Each of them brings their unique flair, having proven their skills in various venues, including the renowned Kraniche bei den Elbbrücken.Together, this trio invites the audience to immerse themselves in a harmonious blend of sound, encouraging exploration of consciousness and connection with the ineffable beauty of music and place.

VVVVVAI & Steffen Bennemann (de)

VVVVVAI & Steffen Bennemann

VVVVVAI works with themes of duality, reflection, and temporal transitions. Geminiaquarius is an ongoing investigation into how states change, overlap, and coexist. The practice centers on reduction, attention, and slow unfolding. Steffen Bennemann has been active in the world of music for more than two decades. After many years as curator and promoter (Nachtdigital Festival), label owner (Holger Records) and DJ, he now focusses on his own sounds. Playing solo as well as in various collaborations, these sounds can be anything from Deep Sea Ambient to celestial Techno.

Vorglühmarkt

Loui Beton (en)

Loui Beton

Lets get besinnlich at the 39C3

Zweite Sahne & Olga Rhythmus (en)

Tesa

A DJ duo from Frankfurt playing technoid Dark Disco. Soundcloud: https://on.soundcloud.com/ieVMVNI9qlqR6BNBHh

Theme

Schedule