meeting topics we encourage members to be active and contribute to the group. if you have a meeting topic or idea, propose it in the discord channel or contact us directly.
where meetings are held at denhac:
700 Kalamath Street, Denver CO 80204
when 4th fridays, 7:00 - 10:00 PM
discord join the community on discord! decode: ZGlzY28gcmQge2RvdH0gZ2d7c2xhc2h9Q2FKV2pVZ3FFVg==
   
next meeting:
2026-05-22 _ - Reversing Bad Brew

Have you ever heard that Macs don’t get malware? Well that’s not true. Bad Brew was a click fix malware campaign that tricked users into downloading and running malware by imitating the homebrew package manager. I will compare an earlier and a more advanced malware sample that shows how the threat actors tactics changed over time

   
possible future topics metasploit
video game console hacking
intro to Ghidra
x86 assembly
arduino fun
local security bypass with firewire or USB
executable file formats
steganography for fun and profit
cracking wireless
current tech in password cracking
malware analysis
   
past meetings:
2026-02-27 Q - Intro to CDX: A cybersecurity training range built for real learning

“What am I working on?”

Building a flexible cybersecurity training range — one that can simulate everything from simple flat networks to complex multi-site enterprises with legacy systems, modern infrastructure, and all the messy realism in between.

Why?

Because learning security requires a safe space to fail. Red teamers need targets they can attack without consequences. Blue teamers need environments where missed detections are lessons, not disasters. Students need room to break things and understand why. CDX provides that space — fully isolated, fully contained, and ready to reset as often as the learning demands.

What makes it different?

The range isn’t just isolated networks in a vacuum. There’s underlying infrastructure that makes it feel like operating within a larger ecosystem — realistic enough to be worth a longer conversation if you’re curious.

Where is this headed?

The project is open source and actively evolving. I’m building exercises, refining automation, and exploring opportunities to support hands-on training for security professionals, students, and teams who want something more than a typical lab experience. Interested in training, contributing, or learning more? I’d welcome the conversation.

2025-08-22 Specters - Car Hacking

Finding vulnerabilities in automobiles… Some old ones and some ??

2025-02-21 Alan Shen - Crash Course into the OWASP API Top 10

At this month’s meeting, Alan will preview his upcoming SnowFROC talk, Crash Course into the OWASP API Top 10. As a DC303 exclusive complimenting the talk, we will practice on the vulnerable applications Completely Ridiculous API (crAPI) and VAPI.

To participate in the interactive part of the event, bring your own laptop with an intercepting proxy (Burp, ZAP, etc.) as well as an API testing tool like Postman. There will be several options for accessing the labs, including using API Sec University’s hosted environment, a local Proxmox lab network we will host in the space for the event, or setting up your own VMs on your laptop.

Recommended Tools:

https://portswigger.net/burp/communitydownload
https://www.zaproxy.org/
https://www.postman.com/
https://github.com/OWASP/crApi (or alternative to deploying a VM: http://crapi.apisec.ai/)
https://github.com/roottusk/vapi (or alternative to deploying a VM: http://vapi.apisec.ai/)

Talk Abstract:

Application Programming Interfaces (APIs) are the glue that allows independently evolving systems to communicate with each other, and are an important focus for security investment due to their privileged access to sensitive data and functionality. Recently, the OWASP API Top 10 has been updated for 2023, so join us as we introduce the OWASP API Security Project. We’ll cover what’s new in the 2023 API Top 10, as well as compare the differences with the previous 2019 version. For those interested in hands-on practice, we’ll also briefly introduce the OWASP crAPI (completely ridiculous API) Project which demonstrates common API vulnerabilities.

2025-01-24 Mark Hoopes - A Web CTF For Everyone

At this month’s meeting we’ll spend some quality time with a truly insecure CRM application that has something for every level of web hacker. Entry level participants can explore a poorly designed authentication system, mid-level hackers will have plenty of opportunities to run SQL and JavaScript Injection attacks, and there is even a pathway to shell, but it will take some real dedication to get there. A walkthrough is available for those who need it so everyone should come away knowing a little more about how to attack (and defend) web applications. Bring your own laptop with an intercepting proxy (Burp, ZAP, etc.) installed to participate.

2024-11-22 Neko - COME LEARN ABOUT WIFI HACKING!

COME LEARN ABOUT WIFI HACKING! We’ll be going over wifi’s evolution over the years, learning about vulnerabilities, mitigations, the tooling available, what’s under the hood of most wifi routers, and how you can run your own audits and even defend wifi in an enterprise or home environment.

INCLUDING PRACTICAL LABS! We’ll be putting out a bunch of wifi access points, maybe even some vulnerable clients, and you’re going to be hacking them.

HACK THE PLANET!

2024-10-25 Cameron Hopkin

Examining the complex relationship between AI and Cybersecurity and Privacy. May do some exploration of the Claude family of AI models. Be ready for good discussion.

2024-09-27 Nuke - Programmable Cryptography: Actualizing Academic Innovation for Novel Technology

Seemly all of a sudden many theorized cryptographic systems are becoming practically usable. Programmable Cryptography is an exciting vision for novel applications using these new tools to empower privacy, verifiability, and much more. This talk will highlight some of these new tools and cover a few key use cases. We will invite discussions from the audience about how we might use these, helping drive adoption and innovation here in our local community and beyond! With any luck, we will come away with a few groups to kick-off a series of talks and workshops around this theme. Speaker bio: Nuke 🌄 is a developer relations advocate at https://risczero.com/ working to evangelize Verifiable Computation and is a huge fan of all things Programmable Cryptography Application. He is a community Steward for https://cryptorado.org that in home for web3 innovators and open source tools to empower people to be self sovereign, focused on engineering coworking and community hackin’. Connect with him on Cryptorado’s Zulip (join at https://Cryptorado.org, or directly on signal

2024-08-23 Mark Hoopes - Hacker Summer Camp Recap and Highlights

Couldn’t make it to Hacker Summer Camp? Made it, but didn’t see every talk available? Join us for a group brain dump on the most interesting talks, research, and tools released at Blackhat, BSides Las Vegas, or DEF CON. Really anything recent and interesting is fair game. Please come with at least one item to share, even if it was just something you saw referenced and would like to know more about.

2024-06-28 Josh Datko - Hardware Hacking for the Young and Old

Have you agreed to a hardware pentest but don’t know where to start? Or perhaps you’re interested in hacking electronics for fun or profit. In any case, this talk will provide a gentle introduction to the hardware hacking scene. If you’re a software hacker, this session will empower you to start probing signals with confidence. For those already familiar with hardware hacking, we’ll delve into advanced attacks such as glitching and power analysis. We’ll even explore some fun analog hacking of cassettes. Join us for an informative and hands-on journey into the world of hardware hacking.

2024-04-26 Jacob Lapenna - Open Source Industrial Control: Turning 2,800 Tons of Metal with Python and Flask

(Preview of upcoming conference talk…)

This is a story of how Python can fit into the physical world around us. It is a story of system design and product development. It is a tale of great breadth, covering distributed computing, custom printed circuits, electromagnetism, some of the largest hydropower generators in the world, and the software and hardware that brings this all together. This tale covers several years of research and development, culminating in a cyber physical system built on open-source software and easily attainable off-the-shelf products and components.

We will also discuss performing security reviews and penetration tests of these types of systems.

2024-03-23 Shawn Webb - HardenedBSD 2024 State of the Union: A Decade of Hardened Bits

Abstract: The HardenedBSD Project is a “spork” of FreeBSD that aims to provide the wider BSD community with a clean-room reimplementation of the publicly-documented bits of the grsecurity patchset for Linux. The cofounders of the project started collaborating in 2013, and the project become official in 2014.

HardenedBSD goes above and beyond its original goal by providing extra security enhancements, exploit mitigation strategies, and unique access into our infrastructure. We seek out ways to serve in global human rights endeavors, navigating the nexus between {cyber,info}sec and human rights.

This presentation recaps the last decade of development and dives into where we aim to go in the next one, five, and ten year periods. We give tangible (yet sanitized) examples of the impact of our human rights focus.

2023-12-29 John Hoopes

Active Directory lab setup, exploitation, and walkthroughs. If you want to set your own up, cloud cost should be under 5 dollars for the evening, or people can use mine. (Sharing means you have to take turns.)

2023-12-01 Austin Ballard

Compilation of the best hacks across AWS, Azure, and Kubernetes; showing off common security misconfigurations.

2023-09-22 Kurt Burrell - CodeQL

Source code analysis is consistently regarded as one of the most effective strategies for uncovering vulnerabilities. However, manual reviews can be time consuming, not to mention difficult to scale for large applications or across application portfolios. Advancements in tooling have traditionally not kept pace with the industry’s needs, with security researchers often relying exclusively on non-security focused solutions such as Developer IDEs and grep.

Enter: CodeQL. CodeQL is a semantic code scanning engine that introduces a rich, custom query language. This query language can augment manual source code review by highlighting areas of interest to focus on, or it can be used to model entire vulnerability classes and provide alerts when those models are detected in a code base.

This workshop starts out with an introduction to CodeQL, how it works and what sets it a part from other solutions. It ramps up quickly to showcase how CodeQL can be applied to find vulnerabilities in real world applications. Tips and tricks, as well as strengths and weaknesses will also be covered. No experience is required.

2023-07-28 Ruby on Rails for Pentesters

Ruby on Rails makes it easy to spin up a web application in minutes, but has proven to be reliable enough to run large company product offerings as well. Web Pentesters don’t technically need to know the platform behind the websites they’re testing, but when we do, we can sometimes find more interesting bugs more quickly. At this meeting we’ll start with the fundamentals by spinning up a trivial Rails app and then take a look at some vulnerabilities that often arise within Rails’s “sensible defaults”. Bring a laptop you’re willing to install Rails on to play along.

2023-04-28 Purple Team 101

The how and why of a threat informed, offensive driven Defense

2023-03-24 API Security Exercises with crAPI and vAPI

There is a recent wave of interest in API security within the broader security community, and APIs continue to be a promising source of security findings due to their ubiquity as the glue that connects disparate systems. With the goal of spending the latter half of the night on hands-on exercises, we will start with an introductory talk that will survey the resources that are available for learning API security, and discuss tips for what to look for when practicing with API-focused testing exercises. After the intro talk, let’s work through any questions regarding the exercises. If you would like to participate in the exercise half of the night, it is recommended in the interest of time to prepare before the meetup the tool/lab setup instructions under the “Lab Setup” chapter of API Sec University: https://www.apisecuniversity.com/courses/api-penetration-testing

2023-02-24 Red Teaming: Windows and Linux Persistence Techniques

Red Teaming for a [redacted] college cybersecurity competition is a great opportunity to work on persistence techniques and develop some useful custom tools. We’ll go over the unique environment of this competition, how that applies to real world scenarios, and also share some tricks that can be played when you have permission to burn the environment to the ground.

2023-01-27 Fuzzing with LibAFL - We will cover the high-level concept of a fuzzer, then dig into the paper written by the authors of LibAFL, and then explore some code.

From the GitHub page: “LibAFL is a collection of reusable pieces of fuzzers, written in Rust. It is fast, multi-platform, no_std compatible, and scales over cores and machines.”

If you want to learn and explore in advance, here are the main resources:

GitHub is here: https://github.com/AFLplusplus/LibAFL

Academic paper is here: https://www.s3.eurecom.fr/docs/ccs22_fioraldi.pdf

2022-09-23 John Hoopes - Fun with Software Defined Radios

2022-08-26 Best of Defcon 2022

2022-06-24 mantis => How to exploit format string bugs with pwntools

2022-04-22 Lost Rabbit Labs - Bluetooth Demystification => Bring the invisible world of Bluetooth communications to light using the newly released 'Bluetooth Demystifier', from Lost Rabbit Labs https://gitlab.com/lost-rabbit-labs. This freely available, open-source software package allows you to examine and explore the Bluetooth/BLE landscape around you. The Lost Rabbit Labs team will demonstrate how to use 'Bluetooth Demystifier', provide the software for all to use, and manage a small CTF around detecting a rogue signal (potential malicious BT device).

Attendees do not have to bring anything as we will be mostly demoing our soon-to-be-released open-source software (projected release between April 18th - April 21st) against the Bluetooth devices we are bringing.

However, if attendees do want to participate, there are three options:

Linux OS laptops that support the BlueZ stack (Not ported to Windows yet nor will it run inside a Linux VM)
A laptop + a Raspberry Pi to configure (the Pi will be running the Bluetooth Demystifier software)
Any device with a web browser to view the front-end application from the LAN (Not entirely sure how many attendees can view this data at once due to Pi's resources)

Attendees can install it before hand (via Linux laptop or on a raspberry pi), with our help at the meetup, or can choose to access the front-end side via a device with a web browser during the event.

2022-03-25 Inroduction to Ghidra for reverse engineering

2022-01-28 Alan Shen -> Log4J Retrospective - Let's discuss the recent remote execution vulnerability in Log4J. To catch us all up to the same base understanding, we will start off with a presentation explaining the root cause and impact of the vulnerability, as well as work through an exercise that demonstrates this vulnerability. Other topics we can discuss include what resources and tooling we've found, remediations we've seen that either work or don't work, and how this event affected our day jobs.

2021-12-17 hxp CTF

2021-11-12 Investigating a real-world database breach

2021-10-22 Mark Hoopes - Windows privilege escalation via USB... @j0nh4t discovered that you can escalate from user to SYSTEM on an unlocked Windows machine just by plugging in a Razer mouse and clicking in the right places. At this meeting we'll take a look at how the specific exploit works and more interestingly how it falls into a no man's land where there are probably a lot more bugs to find. We'll look at how Windows identifies USB devices, decides which driver to install, and then where it downloads the driver from. Armed with that knowledge, we'll take a ~$5 Digispark Kickstarter Attiny85 board (https://smile.amazon.com/s?k=digispark+kickstarter+attiny85) and emulate a Razer device to trigger the vulnerability. If you bring your own board you can go home with a Windows master key (assuming no patches are released). Please come with the Arduino IDE installed for the full DIY experience.

2021-07-23 Editors/Tooling Showcase (vim/tmux)

2021-05-28 OrientDB and SQL Injection Fun - OrientDB is GraphQL under the hood, but implements its own dialect of SQL to make developers feel more comfortable. Unfortunately, despite being listed as fully supported, their Python library never quite implemented parameterized queries. This means that injection exploits are there for the taking if we can just figure out how to make them work using the non-standard SQL. This meeting will be spent getting back to basics on SQLi strategies. A test system will be available and at least one solution will be shared.

2021-03-26 picoCTF live - The CMU picoCTF is ongoing now (it is a two week event). Lots of challenges spread out in the normal categories.

2021-02-26 Discussion - What are you working on?

2021-01-22 Adding a new CPU architecture to Ghidra. Sometimes you come across a virtual machine or CPU description with an executable image that you want to reverse engineer. For instance, this challenge from Synacor has about 21 instructions: https://challenge.synacor.com/ . If we implement the CPU semantics in Ghidra, we should be able to get disassembly and decompilation. Feel free to download the challenge and attempt writing a VM emulator or getting a sense of the opcodes. During the meeting, we will work on adding support for the CPU architecture to Ghidra.

2020-06-26 Android Application Reverse Engineering - We will do a presenter-lead walkthrough of reversing an "easy" Android application and then have a second application for participant practice during the meeting.

2020-02-28 format string exploitation

2020-01-24 Hands-on with Exploit Education (Phoenix) https://exploit.education/phoenix/ . This is a set of binaries with increasing level of difficulties to teach "textbook" exploitation on Linux. We will present a bit of theory first, and then dive into the challenges. The binaries are provided as a Qemu image, so try to set that up in advance.

2019-12 No meeting (because holidays).

2019-11-22 Tilver will be presenting on some of the things that he's encountered in the wild (during professional engagements), and techniques they use when testing.

2019-10-25 Compiler Explorer - Investigating surprising optimization bugs and undefined behavior in C++

2019-09-27 walkthrough of CSAW CTF 2019 challenges: rev500 and crypto

2019-08-23 Discussion: Best of Blackhat/Defcon

2019-07-26 a better zip bomb => presentation on a new type of highly compressed zip bomb, and a technical description of how it works. source code, sample zip bombs, and a writeup are here. if you wish, bring zip-capable software to test.

2019-06-28 Kevin farrow => eaphammer => stealing radius credentials from wpa2-enterprise networks using eaphammer

2019-04-26 TeeOne => Hacking WiFi with the Pineapple Tetra

2019-03-22 Hands on with Ghidra. If you can, pre-install the tool using the instructions here

2019-02-22 xync => Mock CCDC Red Team Engagement. This meeting will be a hands-on red team of a Windows domain environment, post exploitation tools, and pivoting. Prereq: setup an AWS account (free tier is fine) and download/install this: Terraform

2019-01-25 Hands on with the radare2 tool... A (free) swiss army knife of reverse engineering utilities.

Main page

Feature comparison

Book

2018-12-14 Xync => Automated pentest lab deployment

2018-11 Canceling due to Thanksgiving

2018-10-26 A new tool/technique: SILENTTRINITY

A new tool/technique called SILENTTRINITY was released at Derbycon earlier this month. The tagline is “A post-exploitation agent powered by Python, IronPython, C#/.NET.” This looks like something fun to experiment with. Bring a Windows target VM and something to run the C2 server that can do Python 3.7. You will probably also need a development environment setup (see following links). Github repo. Dev enviornment setup. The Derbycon presentation (53 minutes).

2018-09-28 administrativia

2017-10-27 Francisco Donoso - DanderSpritz: How the Equation Group's 2013 tools pwn in 2017

2017-08-25 tilver => Wireless - The uncommon tasks - Some attack stuff as well as how to do useful things using Linux and a wireless adapter. Needed: Linux (Preferably Ubuntu, but will help with other distros), aircrack, wireshark, a wireless adapter that is Linux compatible.

2017-06-16 moose => Defcon CTF challenge walkthrough of awsno

2017-04-21 Tips, tricks, and preparation for CTF (Capture The Flag) events, with realtime PPP CTF play

2016-12-16 Xync will be presenting a walk through of the exploit paths for three CVE from this year. We'll look at the iOS 9.3.4 jailbreak (Trident/Pegasus), DirtyCow, and RowHammer.

2016-02-19 Frameworks to aid in removing custom and commercial packers and protections

2016-01-15 Android development and intent hijacking

2015-12-18 Secure Communications - open discussion

2015-10-16 NES ROM reversing

2015-09-18 CSAW CTF

2015-08-21 Intro to IDA Pro

2015-07-17 Greg Foss => honeypots and active defense

2015-03-20 mantis => Intro to ARM

2014-11-21 mantis => some CTF-style challenges

2014-10-17 Greg Foss => Attacking Wireless Access Points

2014-09-19 csaw ctf

2014-03-21 xync => web hacking challenge

2014-02-21 Greg Foss => hacking Drupal web applications

2014-01-17 CTF game => Ghost in the Shellcode 2014

2013-11-15 dgrif => Breaking weak implementations of RSA in binaries

2013-10-18 mantis => a hacking challenge

2013-09-20 CSAW CTF => https://ctf.isis.poly.edu/

2013-05-17 none

2013-04-19 Plaid CTF => http://www.plaidctf.com/

2013-03-22 Jon McCoy => hacking .net apps

2013-01-18 TJ => Hide and Seek : Geolocation With Metasploit

2012-12-19 cancelled - happy holidays

2012-11-16 syndrowm => advanced ROP exploitation ( slides ) ( code )

2012-10-19 weasel0x00 => Why I can only remember one password

2012-09-21 mantis => CSAW CTF challenges from 2011

2012-08-24 stripe CTF

2012-07-20 defcon CTF preparation

2012-03-16 mantis => challenge: time-locked-safe

2012-02-17 moose => reverse engineering/exploitation of "trivial" CTF challenge binary; dc303-2012-02-17-trivial.tar.gz

2012-01-20 mantis => game/challenge; dc303-2012-01-20-ladder.tar.gz

2011-11-18 tilver => Burp Suite (download Java files here: http://portswigger.net/burp/)

2011-10-21 syndrowm => buffer overflows 101

2011-09-16 tilver => sqlmap

2011-08-26 (4th Friday) Defcon recap

2011-04-15 syndrowm => ROP exploitation against Windows with ASLR

2011-02-11 Brad Arndt => Tedroo Spambot Analysis; Olldbg, IDA, Python writeup

2011-01-21 andy => IDA Pro scripting with IDC/IDAPython

2010-12-16 (thursday) luke => Wii console hacking

2010-11-19 group (Scott, Chuck, MAT, Tuska) => IPv6

2010-10-15 syndrowm => fuzzing with peach

2010-08-20 mantis => hands-on binary (updated) subversion on Linux

2010-07-16 july meeting will be at the ongoing SANS conference at The Westin Tabor Center, 1672 Lawrence Street, Denver, CO 80202 map

2010-06-18 Aaron Pratt => Wifi triangulation

2010-05-21 meeting cancelled due to Defcon CTF qualification round

2010-04-16 mantis => some challenges...

bring IDA/GDB and some scripting skills. file is here

2010-03-26 (was postponed by weather) Don Bailey => DECT sniffing (+ war driving). This meeting will be in the North Classroom Building, room 2002, building #3 (top, center) on the map.

2010-02-19 David Fifield => nmap scripting engine

2010-01-15 mantis => client reversing challenge

2009-12-17 (various) => turbo talks... show us some cool stuff

2009-11-20 Darel Griffin => objective C, debugging and reversing

Equipment: a mac or hackintosh or a *nix machine/VM with GNUstep installed (if you have windowmaker, it is probably already installed)

Tools: OTX (osx) and/or IDA, hex editor, gdb, binutils

Some links for gnustep: http://gnustep.org/ Guide for installing on Linux

2009-10-16 lucipher => win32 challenge: hacking game servers

You will be provided with a win32 game client that talks to a server daemon running remotely. The easy objective will be to insert a fake high score on the server. The hard objective will be to exploit a flaw in the server code running in a Windows virtual machine. You are advised to bring the following so you don’t waste time getting your tools setup:

1) windows operating environment (98, 2000, XP, Vista it shouldn’t matter) 2) a windows disassembler/debugger: ida pro or ollydbg 3) a network sniffer: tcpdump or wireshark 4) a tool for sending network traffic: netcat, ncat, perl, python 5) a hex editor (frhed, xvi32, hexdump) 6) some shellcode for owning windows XP (hard challenge only) 7) network cable 8) power strip

2009-09-18 mantis => CTF network/binary defense

CTF daemons/binaries (1.7 MBytes) CTF (Vegas) packet capture (1.5 GBytes)

2009-08-21 syndrowm => radare - good time binary analysis

http://radare.nopcode.org/new/ http://news.nopcode.org/summer.tar.gz

2009-07-17 syndrowm => hacking with python (and 2 challenges)

2009-05-15 mantis => writing shellcode

source and binary

2009-04-24 Luke Arntson => DLL injection (Windows)

presentation executables source

2009-03-15 don bailey => exploiting null pointer derefence bugs

pptx

2009-02-15 syndrowm => reverse engineering challenge

challenge

2009-01-15 mantis => reverse engineering challenge

challenge source with answers

2008-11-15 ctf from defcon 2008

2008-01-01 we had some meetings focused on the defcon ctf competition

2007-01-01 we had some meetings focused on the defcon ctf competition

2006-12-15 don.bailey => freebsd rootkits

2006-11-15 mdmonk => ossec hids

ossec hids

2006-10-15 mantis => hands-on reversing binaries (part 2)

2006-09-15 mantis => hands-on reversing binaries

2006-07-15 ctf preparation

2006-06-15 ctf preparation

2006-05-15 mantis => insecure programming

insecure programming

2006-02-15 Nicholas Albright => nepenthes

nepenthes

2005-12-15 OSIX security games

OSIX

2005-11-15 NGSEC security games

NGSEC

2005-10-15 mantis => snort backorifice buffer overflow exploit demonstration

buffer overflow

2005-09-15 magictao => scapy packet generation

scapy

2005-06-15 honeywall cdrom 'roo'

honeywall cdrom ‘roo’

2005-04-15 magictao => web application security

2005-03-15 magictao => database encryption product:

Vormetric

2005-02-15 digitalmedix.com => forensics and data recovery

2005-01-15 johan hybinette => windows rootkits (part 2)

2004-11-15 johan hybinette => windows rootkits

2004-10-15 mantis => linux rootkits

2004-09-15 magictao => network assessment techniques

2004-08-15 mantis

metasploit

2004-07-15 magictao

ActiveScout

2004-06-15 commercial stego detection tools