Ever wondered how compiler mitigations are built? Or how a sophisticated build chain attack can target a compiler to place backdoors and other miscreants? Wonder no more, this hands-on workshop shows you how to build your own compiler pass, which can any source code you build to your liking. We'll learn how source code makes its way through the different stages of a compiler into its final binary form, how compilers perform modifications and optimizations of the code, and how they translate their view of the code to a given architecture's binary representation. Students will get a glimpse how some mitigations everybody knows and loves are actually implemented in a compiler. They'll work hands on with LLVM Clang, following along theoretical chapters of the workshop, and eventually they'll implement a Clang plugin themselves to sneak a backdoor into otherwise perfectly secure code. Prerequisites: Linux computer or virtual machine or cloud instance