A zero-day security flaw in Adobe Reader is being actively exploited in the wild. The vulnerability is in Adobe PDF Reader 9.5.3, 10.1.1, 11.0.1 and earlier versions. Researchers with antivirus provider Kaspersky Lab have confirmed the exploit can successfully escape the Adobe sandbox. Until the vulnerability gets patched, FireEye recommends users avoid opening PDF files of unknown origin. There are numerous free, open-source PDF readers available for downloaders.
Source: https://thehackernews.com/2013/02/new-adobe-reader-zero-day-vulnerability_13.html