Becoming familiar with x86 (IA-32 and x64)

Intel x86 (IA-32 and x64) is the most common architecture used in PCs and is powering many servers, so there is no surprise that most of the malware samples we have at the moment are supporting it. IA-32 is also commonly referred to as i386 (succeeded by i686) or even simply x86 while x64 is also known as x86-64 or AMD64. x86 is a CISC architecture, and it includes multiple complex instructions in addition to simple ones. In this section, we will introduce the most common of them, along with how compilers take advantage of them in their calling conventions.