Why it matters: Microsoft has released a crucial bug-fixing update to its Windows Defender antimalware application. VirtualProtect is a function to change the "protection on a region of committed pages in the virtual address space of the calling process," Microsoft explains, and Defender was doing a lot of "useless computations" upon each event while Firefox was generating a lot of ETW events. Mozilla developers said that the Defender update would provide a massive ~75% improvement in CPU usage while browsing the web with Firefox