When asked how to crack a safe open, most people will have a picture in mind, where a thief uses a stethoscope to listen to the inadvertent clicking noises of the lock. Despite usually not being clicking noises, the security of modern computers suffers similar problems. Adversaries can use inadvertent side effects of caching to crack our digital safes open. In this talk we will start with the basics on software-based microarchitectural attacks like Flush+Reload and then look at simple attacks that can be performed. Based on this, we will gain a deep understanding of transient execution attacks like Meltdown and Spectre and learn what the fundamental differences between these are. Finally, we will also look at a few other attacks to complete the overview of microarchitectural attacks.