Malware that exploits a recently patched Adobe Acrobat/Adobe Reader vulnerability has been spreading through email.  Trojan.Pidief.A arrives as an attachment; the email it accompanies generally targets specific organizations and carries subject lines that read "invoice", "statement", or "bill."  The body of the email is empty.  If a user opens the maliciously crafted PDF file, the malware lowers security settings on Windows-based machines and installs other malware.

Adobe issued a patch that fixes this vulnerability on October 22, 2007.

We recommend immediately updating to the latest version of Adobe Acrobat products.  Please make sure all antivirus products are up to date and be cautious when opening any email attachment.  Adobe updates can be found at http://www.adobe.com