Vibe coding a Mach-o parser

Way back in 2021 when I was working on my dissertation I used a Python library called macholibre to parse Mach-O files. There are several other options for parsing these file types. I’m sure they’re all great, but it’s a lot to go through to find some features I want. Mainly, outputting as JSON to easily load into other applications. This seemed like a good opportunity to try vibe-coding a Swift-based Mach-O parser using ChatGPT. After some trial and error, I’ve made MachP available. Let’s look at how this went. ...

April 13, 2025 · 7 min · Kimo B

GPT Detections on Windows and Linux

Introduction This is a follow up to A Little Less Malware, applying the same techniques to Linux and Windows data. There are some differences with this experiment. In the last one, we used Apple’s ESF to collect telemetry, which gave us process group identifiers to work with. In this experiment, I’m using only the Elastic Agent and the process telemetry it provides. Unfortunately, Elastic Agent does not send PGID for Linux, and while Windows notionally supports the concept, in practice it does not exist. First let’s look at a couple of ways to group activity without PGIDs. ...

February 17, 2025 · 5 min · Kimo B

A Little Less Malware a Little More Context: Using AI to detect malicious activity

Introduction A coworker and I gave a talk at Objective by the Sea v7 on using Large Language Models (LLMs) as a behavioral detection. Another speaker, Colson, gave a great talk on why behavioral detections are so useful. LLMs are particularly adept at understanding and processing language-like structures, which include not only traditional text but also command-line arguments. In cybersecurity events, where command-line interactions often reveal attacker behaviors, LLMs can be leveraged to do behavioral detection without needing to be an expert in analyzing malicious actions or writing detections. ...

December 27, 2024 · 16 min · Kimo B

SecurityOnion GPT

Introduction I was recently catching up on some conference videos and saw a talk by Roberto Rodriguez on Empowering Security Teams with Generative AI: GPT models. This got me thinking about how to integrate GPT to hunting with Security Onion. Goals: Summarize activity found in Security Onion Enrich activity with MITRE ATT&CK attribution Convert English questions to Kibana Query Language to hunt In this post, I’ll tackle goals 1 and 2. I’ll do goal 3 in a separate post. These experiments will be conducted in Jupyter lab. ...

February 12, 2024 · 14 min · Kimo B