Microsoft yesterday patched a vulnerability, MS15-085, in Windows Mount Manager, a driver in mountmgr.sys. Microsoft rated the vulnerability (CVE-2015-1769) important because it requires local access to a machine to exploit. Microsoft announced that in addition to the patch it was also making an event log available that detects attacks against this vulnerability. The flaw, Microsoft said, is being exploited in targeted attacks and patching this vulnerability should be prioritized.
Source: https://threatpost.com/microsoft-patches-usb-related-flaw-used-in-targeted-attacks/114240/