Microsoft has started releasing every second Tuesday of every month a new version of it for free software Microsoft Malicious Software Removal Tool, a security application that lends a helping hand to users trying to get rid of specific malware "infections".
Although there are none available notes of the current version, and since these Patches are updated every second Tuesday of each month (today is for the month of November), then most likely the 5.6 version comes with features to detect and remove new infections.
Of course, the app still provides support for all current versions of Windows, starting with XP and ending with the latest Windows 8.1.
Keep in mind, however, that Microsoft's Malicious Software Removal Tool is not a real-time software security product that is supposed to only help users get rid of certain malware infections. And of course it's a completely free software.
The application only acts as a guide and guides you through the entire scan and removal process, so if you have enough time to try to clean your computer, download the Microsoft Malicious Software Removal Tool 5.6 now.