Because the CLR is a managed environment there are several components within the runtime that need to be initialised before any of your code can be executed. This post will take a look at the EE (Execution Engine) start-up routine and examine the initialisation process in detail.
Lots of interesting stuff happening before your code even gets executed. Many of the pieces can log.
Source: [WayBack] The 68 things the CLR does before executing a single line of your code (*) · Performance is a Feature!
Via: [WayBack] Good stuff to know! – Ondrej Kelle – Google+
–jeroen