Since the early 2000's Microsoft has distributed patches on the second Tuesday of each month. Bad guys, good guys, and many in-between compare the newly released patches to the unpatched version of the files to identify the security fixes. Many organizations take weeks to patch and the faster someone can reverse engineer the patches and get a working exploit written, the more valuable it is as an attack vector. Analysis also allows a researcher to identify common ways that Microsoft fixes bugs which can be used to find 0-days. Microsoft has recently moved to mandatory cumulative patches which introduces complexity in extracting patches for analysis. Join me in this presentation while I demonstrate the analysis of various patches and exploits, as well as the best-known method for modern patch extraction.