Two days after Adobe released this Security Advisory (http://www.adobe.com/support/security/bulletins/apsb08-19.html) the first exploits have been seen in the wild, those examples were not recognised by the VirusTotal bank of AV applications.
Please follow the advice given in the advisory and update to the latest version of Acrobat or Acrobat Reader (v8.1.3 or, if you can, v 9.0.0). If updating from an earlier version to v9.0.0. you are advised to first remove all traces of that version via the "Add/Remove" function (XP) or "Programs and Features function (Vista) of Control Panel.