9 posts
Seven tasks spanning forensics, reverse engineering, cryptanalysis, and application security
The 2025 NSA Codebreaker Challenge was my first Codebreaker, and I completed all seven tasks, becoming one of 82 students to finish the full challenge. It was a …
Archive handling and the boundary between data and code
Now that we have access to the hidden channel the adversary is using, our military counterparts want to act quickly to destroy the adversary’s capacity …
A lesson in destination-specific authorization
This high visibility investigation has garnered a lot of agency attention. Due to your success, your team has designated you as the lead for the tasks ahead. …
The investigative handoff from malware to infrastructure
Task 5 - Putting It All Together - (Cryptanalysis) NSA analysts confirm that there is solid evidence that this binary was at least part of what had been …
Understanding an obfuscated Linux sample
Task 4 - Unpacking Insight - (Malware Analysis) Once back at NSA the team contacts the NSA liaison at FBI to see if they have any information about what was …
Moving from network evidence to a router memory image
Task 3 - Digging Deeper - (Reverse Engineering) The network administrators confirm that the IP address you provided in your description is an edge router. …
Tracing inconsistent DNS responses back to a router
Task 2 - The Hunt Continues - (Network Forensics) With your help, the team concludes that there was clearly a sophisticated piece of malware installed on that …
Finding a suspicious artifact in an EXT2 image
Task 1 - Getting Started (Forensics) You arrive on site and immediately get to work. The DAFIN-SOC team quickly briefs you on the situation. They have noticed …
A useful cryptography cheatsheet
Cryptography challenges are one of the most common categories in Capture the Flag (CTF) competitions. This guide provides a focused overview of essential …