Detecting task modifications

In the previous post we looked at different ways to inject code into tasks on macOS. The goal being to create increased awareness of the type of methods attackers writing malicious code on macOS might use. In this post I wanted to focus in on the same issue of code injection but from a defenders point of view.

6 min read

Code injection on macOS

I was recently reviewing the MITRE ATT&CK™ knowledge base and came across the page on process injection techniques for privilege escalation. For those that are not aware of what the MITRE ATT&CK™ knowledge base is, it’s a group of documents and definitions that cover common adversary tactics and techniques. The macOS and Linux sections for process injection were lumped together and not very detailed. In some cases it seemed like the information wasn’t even accurate for macOS. This article covers common process injection techniques that apply to macOS.

11 min read

Swift value types vs reference types

A common question that comes up when people start Swift development is what’s the difference between a struct and a class? The standard answer is structs are value types and classes are reference types. The Swift Programming Language book has a whole section reviewing this concept in more detail. From a reverse engineering perspective I always find it interesting to dive under the hood and see how the compiler actually handles the different concepts from high level languages. This post presents a very simple example of a struct and class in Swift and how the compiler deals with them.

6 min read

syspolicyd internals

With my previous post I took a look at the SystemPolicy.framework and how it kept track of 32-bit applications that had been run. In the process of looking into that I ended up looking into the internals of syspolicyd. Way back in macOS 10.10.5 syspolicyd was part of the security_systemkeychain source code that Apple releases with each version of macOS. Unfortunately since that time syspolicyd was moved out of the security_systemkeychain package and closed sourced. This post details the internals of syspolicyd as it is today in macOS 10.14.x and covers both what services it provides and what clients connect and use its functionality.

23 min read