Adobe warned today that hackers appear to be exploiting a previously unknown security hole in its PDF Reader and Acrobat programs.
In an advisory published Wednesday, Adobe said a critical vulnerability exists in Acrobat and Reader versions 9.3.4 and earlier, and that there are reports that this critical vulnerability is being actively exploited in the wild. The company says its in the process of evaluating the schedule for an update to plug the security hole.
Meanwhile, an evil PDF file going around that leverages the new exploit currently is detected only by about 25 percent of the anti-virus programs out there (the Virustotal scan results from today are here, and yes it’s a safe PDF).
Adobe’s advisory doesn’t discuss possible mitigating factors, although turning off Javascript in Reader is always a good first step. Acrobat JavaScript can be disabled using the Preferences menu (Edit -> Preferences -> JavaScript and un-check Enable Acrobat JavaScript).
Better yet, consider using an alternative PDF reader that isn’t quite so heavily targeted as Adobe’s, such as Foxit, Sumatra, or Nitro PDF.