If you receive an email message that claims to be distributing a Microsoft security update, it is a hoax that may contain malware or pointers to malicious websites. Microsoft does not distribute security updates via email.
The Microsoft Security Response Center (MSRC) uses PGP to digitally sign all security notifications. However, PGP is not required for reading security notifications, reading security bulletins, or installing security updates. You can obtain the MSRC public PGP key at <https://technet.microsoft.com/security/dn753714>.
Webroot® SecureAnywhere™ Internet Security Complete 2014 Beta Tester v184.108.40.206 on my main system Windows 7 Ultimate 64bit & on Win XP 32bit, Win Vista 32bit, Win 7 32bit, Win 8.1 Pro 32bit & 64bit all on VM's.