Co přesně je na KB3156417 škodlivého, tedy jen proto, že se někde objevila na nějakém seznamu?
https://support.microsoft.com/en-us/kb/3156417
May 2016 update rollup for Windows 7 SP1 and Windows Server 2008 R2 SP1
The May 2016 update rollup package for Windows 7 Service Pack 1 (SP1) and Windows Server 2008 R2 SP1 resolves issues and includes performance and reliability improvements. We recommend that you apply this update rollup as part of your regular maintenance routines. Check out the fixed issues in this update. Also notice that there is a prerequisite and a restart requirement for installing this update.
Issues that this update fixes
This update package fixes the issues that are documented in the following:
KB3155039 Error 1326 when you change domain account password in Windows
KB3155218 Memory leak occurs in the Lsass.exe process after you install security update 3067505 in Windows