You are referred to the thread starting at <post#=672,358>post 672,358</post#> for information about an exploit in PDF files which is fixed by the 8.1.1 upgrade to Adobe Reader.

QUOTE: "A day after Adobe patched a serious security hole in its Reader and Acrobat programs, miscreants are flooding email inboxes with malware-tainted PDF files that try to remotely hijack vulnerable computers."