Microsoft released a new patch for the LNK vulnerability exploited by Stuxnet after it learned original patch from 2010 failed and left Windows machines exposed. Microsoft today is expected to release a security bulletin, MS15-020, patching the vulnerability (CVE-2015-0096) It is unknown whether there have been public exploits of patched machines. The vulnerability works on Windows machines going back to Windows XP through Windows 8.1, and the proof of concept exploit evades the validation checks put in place.
Source: https://threatpost.com/patched-windows-machines-exposed-to-stuxnet-lnk-flaw-all-along/111558/